Good day all have 1 deep cycle battery 110 amp wont to fit second and inverter have been told second battery should be same power output as first ?? and whats a good inverter for using when camping out weve got 350 amps off solar and 3.5 kva genie tow tub 2014 bt 50
van 2015supreme exc
warhorse said
08:32 AM Mar 7, 2017
hi barme1,need more info,how old is your existing battery? if its got a bit of age to it,better to replace it and start with 2 new batteries of same a.hr....as for the inverter,quality will vary with brand, a lot of the cheap ones off ebay are of acceptable quality but have a higher standby current use,size will depend on what you need to power and in turn will dictate if you have enough solar to maintain everything,main thing to remember is don't discharge your batteries below 50% as it shortens battery life. cheers ray
-- Edited by warhorse on Tuesday 7th of March 2017 08:43:23 AM
Mike Harding said
12:45 PM Mar 7, 2017
There have been a number of detailed threads covering this area recently and it will be well worth you doing a search and reading them.
Regarding multiple batteries:
Unless your battery is close to new it is no longer a 110Ah battery but a (110Ah - xAh) battery. Lead acid batteries degrade naturally over time, temperature and use or abuse. After five years of careful use I would expect a 100Ah battery to be around a 40Ah battery.
The problem is that the aging changes the way the battery accepts and produces current and if you put it in parallel with a battery with different electrical characteristics they'll, kind of, fight each other a bit and it is likely the lifespan of one will be shortened - probably the lower capacity battery. You can do it and it will work but it's not a great idea.
Jaahn said
01:16 PM Mar 7, 2017
BARME1 wrote:
Good day all have 1 deep cycle battery 110 amp wont to fit second and inverter have been told second battery should be same power output as first ?? and whats a good inverter for using when camping out weve got 350 amps off solar and 3.5 kva genie tow tub 2014 bt 50
van 2015supreme exc
Hi BARME1
Lots of doom and gloom about the old battery If the old one is going OK and not so old then just pair it up with another of the same type and see how it goes You can easily buy another new one anytime if you need it !
More to the point, regarding the inverter is what you will be running on it. If a big user of power then it is important to get the cables and connections short, generous size and well done. Often the budget inverters are OK but the cables etc are obviously under size. As said the load sets the size and how much time of use sets the battery capacity required to run it, basicly !
If you only want to charge things or use the telly or something like that then a smaller one will be better as the efficiency is better. I assume you are talking about a full sine wave type as you should get that type. Do not get a big one and only use a small amount of current. Bigger just means more wasted power. What ever you get, it should not plug into a socket but be properly wired to the batteries.
Jaahn
PS do you mean 350W of solar. That sounds OK for 2x 110Ahr batteries.
Mike Harding said
01:37 PM Mar 7, 2017
>Jaahn >If the old one is going OK and not so old then just pair it up with >another of the same type and see how it goes wink You can easily buy >another new one anytime if you need it !
He can do that... and it will work....
The problem is: Let's assume a well cared for battery has a life of five years.
His existing 110Ah battery (battery A) may be half way through its life and, perhaps, now only a 70Ah battery.
If he buys a new 110Ah battery (battery B) and puts it in parallel with a 70Ah battery the 70Ah battery is going to have a hard time which will shorten its life and its capacity.
In turn this will place a greater load on the 110Ah battery which will shorten its life.
At some point battery A will fail and he'll have to buy a new 110Ah battery which he'll put in parallel with battery B which is now a year or two old, has had a hard life and is probably only a 60Ah battery.
And so on....
In addition he'll never actually have 220Ah of storage but something less.
Two batteries of the same model bought from fresh stock at the same time and, ideally, the same batch will tend to age in a similar manner.
MH
Peter_n_Margaret said
05:56 PM Mar 7, 2017
The second battery should be the same chemistry/style as the first, but it can be any size/capacity that you can fit.
Cheers,
Peter
Aus-Kiwi said
11:05 PM Mar 8, 2017
Think about 12V appliances too ? TV, fridge etc.. I find since fitting 12v the elect system worked way better.. Charging phones etc off 12V is fine also.. Just requires a double or triple plug..
vik351 said
12:46 PM Mar 9, 2017
Aus-Kiwi wrote:
Think about 12V appliances too ? TV, fridge etc.. I find since fitting 12v the elect system worked way better.. Charging phones etc off 12V is fine also.. Just requires a double or triple plug..
Huh...??? I find since fitting 12v the elect system worked way better..
Power points to existing 12 v...???
vik...
Aus-Kiwi said
05:11 PM Mar 9, 2017
I fitted 12V appliances, As in TV, Sat box etc.. Yes 240v for hot water jag etc if we need it..
Even boiling an elect jug off batteries through inverter is pulling a massive current.. I found charging things like phones, Ipads etc much better off 12V supply.. 240v is there when hooked up at camping ground.. But we are set up for free camping for weeks on end.. 400 watt solar and [sorry] 5Kw quiet generator ..
T1 Terry said
11:18 PM Mar 9, 2017
If you need to buy 2 new 110Ah battery it would make more $$ sense to buy a 100Ah lithium ferrous battery. It will handle the inverter loads better, recharge faster and last longer for around the same $$ outlay as AGM batteries of an equal quality. The other advantage with lithium ferrous batteries is you can increase the capacity later on without having the throw away the original cells, new and old will work together just fine. As an example, one well know and highly respected A van owner powered his microwave and other 240vac electrical appliances from a single 100Ah lithium ferrous battery and it was still going strong when he sold the vehicle to upgrade to a more off road vehicle. There is no value in buying old out-dated technology when the new technology will do what you want for around the same price
As far as inverter size/brand/price, depends just what you want to do with it but make sure it is a pure sine wave type, modified sine wave is just not suitable for electronic controlled equipment and will damage it. If you buy a cheapie ebay inverter the capacity required must be greater than the biggest load by around 10%, for example to run a 2,000w kettle you need an inverter with a rated output of at least 2200w, so one advertised as 2,000w - 4,000w won't do the job, the second number is as good as meaningless for practical use and the first number often refers to the input power required at max load, not the mx it can put out continuously. To power a 2,000w kettle you need a 2,500w inverter and this will be big enough to power a microwave or coffee machine or hair dryer..... one at a time and only for as long as the battery capacity lasts of course.
If you want to power a CPAP machine or recharge phones or power the electric blanket, a 300w to 400w inverter will be sufficient.
Hope that helped
T1 Terry
warhorse said
12:56 AM Mar 10, 2017
Hi Terry,you have got me interested.i have never heard of lithium ferrous battery's,could you please explain the difference between them & lifepo4 lithium battery's. cheers Ray
Mike Harding said
09:41 AM Mar 10, 2017
T1 Terry wrote:
There is no value in buying old out-dated technology when the new technology will do what you want for around the same price
I don't think the same price claim stands up:
Let's compare a 60Ah LiFePO4 battery with a 100Ah AGM battery - there is an argument you'll get a similar amount of energy out of each because of the different recommended maximum depth of discharge:
Hi Terry,you have got me interested.i have never heard of lithium ferrous battery's,could you please explain the difference between them & lifepo4 lithium battery's. cheers Ray
:lol: Lithium ferrous is just a way of stopping the confusion with lithium iron and lithium ion looking to be one and the same thing rather than lithium iron (lithium ferrous) being part of the much larger group of lithium technology batteries known as lithium ion due to the ion exchange being their method of electrical energy transfer as apposed to the chemical reaction used in lead acid batteries (flooded cell, AGM, Gel, Lead crystal etc). Li (lithium) Fe (ferrous or iron) P04 (phosphate) LYP is lithium yttrium ferrous phosphate and the improved version of LiFeP04 developed and manufactured by Winston Battery Corporation, Been about for around 5yrs or so and has far better cold tolerance when charging/discharging and increases cycle life, LFP is good but aged technology, LYP is just an improved version better suited to cycling type storage as used in an RV application.
T1 Terry
-- Edited by T1 Terry on Friday 10th of March 2017 04:51:06 PM
T1 Terry said
05:17 PM Mar 10, 2017
Mike Harding wrote:
T1 Terry wrote:
There is no value in buying old out-dated technology when the new technology will do what you want for around the same price
I don't think the same price claim stands up:
Let's compare a 60Ah LiFePO4 battery with a 100Ah AGM battery - there is an argument you'll get a similar amount of energy out of each because of the different recommended maximum depth of discharge:
I guess I could find links that indicate your AGM batteries are either over priced or under priced, but quality for quality using say Winston LYP cells and Fullriver or Century or Ritar for example, 100Ah of LYP will deliver 100Ah and retain better than 12vdc at even a 100 amp discharge rate (see attached chart) where any of the mentioned brands would be struggling to deliver 100Ah while retaining the 12v at much better than 10 amps from 200Ah capacity.
As far as the recommended discharge limit, you seem keen to extend the lead acid limit below 40% SOC yet ignore the need to retain 12v under load as part of the comparison. I'm quite happy to withdraw my criticism and accept you are correct if you can display that the lead acid battery you mentioned will deliver 60Ah at a rate higher than 5 amps and retain the 12v under load requirement, but keep in mind the 60Ah lithium battery... well an Winston LYP version at any rate, will deliver a lot more than 60Ah if only loaded to 5 amps throughout the test before the loaded voltage drops below 12vdc. Again, refer to the chart, that 100Ah is rated with a 100 amp load, with a 50 amp load it delivers more than the advertised 100Ah so just how much you could get at only a 5 amp load is really an unknown.
Need to compare apples with apples to really see the comparison, any of the lead acid batteries listed above are simply batteries, no BMS or charge control etc, a 100Ah Winston LYP battery strapped with cell links is around the $800 mark if we are going to compare batteries with batteries.
For clarification, the 0.5c means 50% of the advertised capacity as a load in amps (50 amp load from a 100Ah battery) 1C is 100% load etc
I agree with most of what you write - it's just that the two technologies are not compatible price wise with the lithium being about 4 x the cost of a lead acid.
If one requires the specific advantages of lithium then it may be worth paying the extra but for most it will not.
T1 Terry said
07:00 PM Mar 10, 2017
Mike Harding wrote:
T1-Terry:
I agree with most of what you write - it's just that the two technologies are not compatible price wise with the lithium being about 4 x the cost of a lead acid.
If one requires the specific advantages of lithium then it may be worth paying the extra but for most it will not.
This is the part I can't follow, if the requirement is 100Ah @ 12v min then 200Ah of lead acid min is required, even more if the current draw is greater than 5 amps per 100Ah capacity once the SOC drops below around 60%. With a 100Ah Winston LYP 100Ah battery at around the $800 mark that would mean you were buying deep cycle 100Ah lead acid batteries for under $200 each...... then the quality wouldn't be a fair match and over a 1500cycle use period the lithium would still be like new yet the AGM would be in need of yet another replacement.
Many people confuse cycle use and calendar days, the calendar day life of a lithium battery is as yet unknown, the Mars Rover is still going so we know it must be longer than 10 yrs in a very hostile environment yet used every day if it had a chance to recharge.
Cycle life for a lithium battery is discharged to 2.8v in each cell and recharged to a rested voltage of 3.4v in each cell, lead acid is 700 cycles at a 50% discharge and recharged to 100%, less if you discharge it deeper and more if discharged less. The cut off point for lead acid is 60% of advertised capacity, this actually means less than 10% available before the voltage drops below 12v under load. There are a lot of passed on lead acid batteries out on the road just waiting for the owner to discover just how little capacity is really left in their batteries. A few poor solar days and it's all over as the weak cell gets very deeply discharged and never recovers. A string of 12v batteries only requires one battery to have one of 6 cells fail and that will destroy the other batteries in the series chain if the user doesn't catch it very quickly and remove the connections from the now dead battery. The other batteries will keep trying to recharge it till they are all pulled down to the point where a cell will fail. Brand new batteries can sort of take that sort of punishment, batteries with a bit of capacity loss already can't take it and the weakest cell fails making the battery useless for the purpose intended.
Lithium battery packs properly build and monitored do not suffer this problem, a cell never suddenly drop dead, the death spiral is long and clearly evident for mths if not yrs so the appropriate action can be taken at the owners convenience, not when the battery suddenly didn't do what was asked.
T1 Terry
-- Edited by T1 Terry on Friday 10th of March 2017 07:04:50 PM
Jaahn said
07:01 PM Mar 10, 2017
Hi
I also think the comparison of the two technologies does not stack up price wise. Terry is a bit one eyed about it as he is an industry expert. That's OK but some balance is necessary for the sake of people not as knowledgeable about the subject.
With Lithium batteries Terry himself has said that you need a 'system' not just a battery, so there is more to buy there. Where as with the old technology LA batteries they are available commonly for a good price, not only premium ones for a premium price, and the associated gear required is also commonly available for a good price.
If you want to spend the money on Lithium that's OK and benefits come with it, but if you just want to "keep the lights on" they do not care what battery the electrons come out of. Your choice but I believe the lithium way will cost considerably more !
Jaahn
T1 Terry said
04:30 PM Mar 11, 2017
Jaahn wrote:
Hi
I also think the comparison of the two technologies does not stack up price wise. Terry is a bit one eyed about it as he is an industry expert. That's OK but some balance is necessary for the sake of people not as knowledgeable about the subject.
With Lithium batteries Terry himself has said that you need a 'system' not just a battery, so there is more to buy there. Where as with the old technology LA batteries they are available commonly for a good price, not only premium ones for a premium price, and the associated gear required is also commonly available for a good price.
If you want to spend the money on Lithium that's OK and benefits come with it, but if you just want to "keep the lights on" they do not care what battery the electrons come out of. Your choice but I believe the lithium way will cost considerably more !
Jaahn
:lol: @ x $200 for cheap LA that last for how long? Then another $400 or more due to inflation now equals the cost as the same 100Ah useable from the quality lithium battery that would still be doing what it was bought for, storing energy and releasing it when needed. That how long in both cases depends on some form of battery management.
For those who "just want to keep the lights on" won't have them on for long without some form of battery management. Even a start battery will require some sort of battery management if it's going to last more than a few weeks because it will go flat if not charged. Simply connecting a solar panel or the alternator direct to the battery will over charge it and destroy it, they both need a voltage regulator, the alternator has it built in these days but it is still there, the solar requires a solar regulator to act as the voltage regulator. Lithium batteries are no different, they also require a voltage regulator or they will be destroyed by over charging. The difference is the lead acid battery has no method of measuring cell voltages so any cell in the battery can end up getting over charged resulting in a reduced cycle life, just because you can't see the problem doesn't mean it doesn't exist. Lithium again is no different, it will suffer damage if a cell is over charged, the difference is properly built lithium batteries can have their cell voltage monitored and for a the grand total of $30 plus $5 for the plug and leads to install such a monitor..... but that is a step beyond comparing batteries with batteries, we are now talking about monitoring to extend the batteries life. You can do without the cell monitoring if you want, it's your hard earned $$ that bought the battery so it's up to the user to decide if a bit of insurance is worthwhile or not, the battery really doesn't care.
Any additional costs revolves around reducing the time spent looking after the battery pack, if you want it to look after itself yet still get the long life then you have to pay for the control equipment to do that. If you are happy to do it all yourself then even the $35 can be saved and just use a multi-meter, but I'm sure I could find better things to do with my time than watch batteries 24/7 If you don't want the lights to go out without you expecting it then a battery monitor is required, again, an aid for the user and not mandatory equipment so that can not be included in the price of the battery.
If you are going to compare $$ costs then you do need to compare apples with apples
T1 Terry
Jaahn said
10:35 AM Mar 12, 2017
Hi
Terry likes to compare our good old Delicious or Pink lady apples with Seckai Ichi apples to make various statements. A bit of a stretch for most supermarket(ebay) shoppers. But who knows how much better the Seckai Ichi apples are as I have never had one ?? Not likely either !
If you can afford the best then spend away, Terry will help you. If not then find advice less biased and add up the costs for yourself ! I do not see many people towing their rigs with RR or even BMW and Audi 4WDs so a budget must be important to some people here.
Jaahn
T1 Terry said
01:15 PM Mar 12, 2017
Jaahn, go back to the thread title and give an honest costing and expected cycle life to show your method is better budget wise. By the way, there is no such thing as Good Old delicious apples, they are either fresh and good or tasteless/flowery old, but then anyone who knows their apples already knows that ;)
Lithium is not for the caravan park jumper who never free camps, ever, I can't see why they need a battery at all really.
Lithium is not for the one or two week ends a yr caravan user who doesn't want to use an inverter, lead acid will do that job fine
Lithium is for those who use their RV a lot, they like to camp off grid even in a caravan park because those spots are roomier and further away from the pool and jumping castle. Lithium is for those who do want to use an inverter and who want to move towards 21st century travelling with a few of the comforts from home.
I note it rarely the other half who says they are perfectly happy with roughing it and being restricted in what can be used when, ever thought that might be the reason they are not as keen on travelling as the driver??? Happy wife is a happy life, is parking the van in the yard most of the time a good financial choice when you could be out there enjoying it which was the reason you spent all those $$ in the first place.
T1 Terry
Mike Harding said
01:23 PM Mar 12, 2017
T1 Terry: do you have any kind of commercial interest in lithium batteries?
T1 Terry said
02:34 PM Mar 12, 2017
Mike Harding wrote:
T1 Terry: do you have any kind of commercial interest in lithium batteries?
Yes, my wife became frustrated by the amount of gear I had around the house so she bought a workshop for me to play in, not many blokes have a wife like that eh :lol: I've mentioned else where that I install custom lithium battery systems using as much of the users original equipment as possible by building an interface to adapt just about anything to work well with lithium batteries. Hundreds of systems fitted and all say a similar thing, couldn't live our present lifestyle without them.
I don't want to promote any business interests here, that is not my intention so I won't name the business set up and run by my wife, my interest is in promoting lithium batteries for what they are and trying to quash the myths set up about cost, safety and use that seems to be so wide spread across the internet.
T1 Terry
El Gringo said
07:05 PM Mar 12, 2017
Here's a spread sheet I worked on to compare AGM to LFP.
This wont be for everybody as I want to have lots of power, but I think the sums stand up for most situations anyway.
Cheers.
I have removed the spredsheet due to it being wrong...
-- Edited by El Gringo on Sunday 12th of March 2017 08:18:58 PM
Peter_n_Margaret said
07:43 PM Mar 12, 2017
Something a bit wrong there...
600Ah @ 24V = 10 @ 120Ah/12V, not 10 @ 160Ah.
And 10 @ 120Ah/12V should cost about $3,850, not $5,500.
And if you are happy to use a Dingo for the Li (plus BMS) then you can also use it for the AGMs (minus BMS), so your control comparison is somewhat biased.
Cheers,
Peter
El Gringo said
07:54 PM Mar 12, 2017
Perter you missed the very top line of the spreadsheet showing what you need to get for the same (similar) usable amps. 10 x 160a = 300a usable @ 24v (50% DOD) compared to the LFP at 320a usable. (80% DOD)
As i also mentioned it is for my comparison, the control system is as yet not fully costed, but if anything I have allowed equal amounts dollar wise so there should be no bias there either really.
Yes I have decided on using LFP, but this is what helped convince me.
Cheers.
El Gringo said
07:58 PM Mar 12, 2017
Opps, I'll take that back, my sums were incorrect....
El Gringo said
08:17 PM Mar 12, 2017
Well Thanx for that Peter, my brain isn't always to be trusted and I hadn't had anyone check it first for me.
I will attach a revised one though with corrected figures. (Just in case anyone is actually interested.)
The control systems will not be the same costs for each system.
50% DOD is a nominal % for AGMs. There is no damage to go much lower to keep things running, so that 80%/50% DOD comparison is also flawed.
The Li excel for big heavy continuous loads, but not everyone needs that feature.
If AGMs are currently providing the service that you require then the only real benefit to Li is the weight saving plus a life increase that is still to be proven.
They are all "just batteries".
Cheers,
Peter
T1 Terry said
02:53 PM Mar 13, 2017
Peter_n_Margaret wrote:
The control systems will not be the same costs for each system. 50% DOD is a nominal % for AGMs. There is no damage to go much lower to keep things running, so that 80%/50% DOD comparison is also flawed. The Li excel for big heavy continuous loads, but not everyone needs that feature. If AGMs are currently providing the service that you require then the only real benefit to Li is the weight saving plus a life increase that is still to be proven. They are all "just batteries".
Cheers, Peter
There is a need for a qualifier as far as depth of discharge goes, both chemistries can be discharged till absolutely no voltage is available but the Li would by far exceed to output obtained from the AGM. The result would be the same though, both batteries would be stuffed.
The best indicator is the advertised battery nom. voltage, 12v for a 12v battery, stands to reason really as that is what was bought, a 12v battery. Now comparing available output at say a 5 amp load per 100Ah of advertised capacity until the loaded voltage dropped below 12v a good AGM battery will pull up at around 50% of the advertised capacity. An LYP battery will deliver more than 100% of its advertised capacity using the same test and that is the only test where the AGM battery stands a ghost of a chance competing head to head. Step up the load used to rate lithium batteries, 50% of the advertised capacity or 50 amps per 100Ah advertised capacity and the LYP battery will deliver all 100% of its advertised capacity before dropping below 12v....... how many Ah can you draw from a 100Ah AGM battery under a 50 amp load before the voltage drops below 12v?
Back to the apples v apples comparison to first decide just how many Ah of AGM batteries are required to match the load/time curve you require, then do a cost comparison. At the moment the cost comparison is being made using a C20 load (5 amps per 100Ah of advertised comparison) so 2 x 100Ah AGM matched up against 100Ah of LYP requires the load to be less than 10 amps to give the AGM batteries a fighting chance..... but then at a 10 amp load the LYP battery would deliver a lot more than 100Ah before it dropped below 12v so the comparison is still not on an even basis is it?
T1 Terry
Peter_n_Margaret said
06:47 PM Mar 13, 2017
T1 Terry wrote:
...... how many Ah can you draw from a 100Ah AGM battery under a 50 amp load before the voltage drops below 12v?
Who cares? Not me and not anyone I know. Certainly not the OP.
I do know I have been starting the OKA for over 7 years now from a single 120Ah/12V Fullriver AGM. That takes about 400A for up to 45 seconds in the winter. That is not relevant to any discussion here either.
Good day all have 1 deep cycle battery 110 amp wont to fit second and inverter have been told second battery should be same power output as first ?? and whats a good inverter for using when camping out weve got 350 amps off solar and 3.5 kva genie tow tub 2014 bt 50
van 2015supreme exc
hi barme1,need more info,how old is your existing battery? if its got a bit of age to it,better to replace it and start with 2 new batteries of same a.hr....as for the inverter,quality will vary with brand, a lot of the cheap ones off ebay are of acceptable quality but have a higher standby current use,size will depend on what you need to power and in turn will dictate if you have enough solar to maintain everything,main thing to remember is don't discharge your batteries below 50% as it shortens battery life. cheers ray
-- Edited by warhorse on Tuesday 7th of March 2017 08:43:23 AM
There have been a number of detailed threads covering this area recently and it will be well worth you doing a search and reading them.
Regarding multiple batteries:
Unless your battery is close to new it is no longer a 110Ah battery but a (110Ah - xAh) battery. Lead acid batteries degrade naturally over time, temperature and use or abuse. After five years of careful use I would expect a 100Ah battery to be around a 40Ah battery.
The problem is that the aging changes the way the battery accepts and produces current and if you put it in parallel with a battery with different electrical characteristics they'll, kind of, fight each other a bit and it is likely the lifespan of one will be shortened - probably the lower capacity battery. You can do it and it will work but it's not a great idea.
Hi BARME1
Lots of doom and gloom about the old battery
If the old one is going OK and not so old then just pair it up with another of the same type and see how it goes 
You can easily buy another new one anytime if you need it !
More to the point, regarding the inverter is what you will be running on it. If a big user of power then it is important to get the cables and connections short, generous size and well done. Often the budget inverters are OK but the cables etc are obviously under size.
As said the load sets the size and how much time of use sets the battery capacity required to run it, basicly !
If you only want to charge things or use the telly or something like that then a smaller one will be better as the efficiency is better. I assume you are talking about a full sine wave type as you should get that type. Do not get a big one and only use a small amount of current. Bigger just means more wasted power. What ever you get, it should not plug into a socket but be properly wired to the batteries.
Jaahn
PS do you mean 350W of solar. That sounds OK for 2x 110Ahr batteries.
>Jaahn
>If the old one is going OK and not so old then just pair it up with
>another of the same type and see how it goes wink You can easily buy
>another new one anytime if you need it !
He can do that... and it will work....
The problem is:
Let's assume a well cared for battery has a life of five years.
His existing 110Ah battery (battery A) may be half way through its
life and, perhaps, now only a 70Ah battery.
If he buys a new 110Ah battery (battery B) and puts it in parallel
with a 70Ah battery the 70Ah battery is going to have a hard time
which will shorten its life and its capacity.
In turn this will place a greater load on the 110Ah battery which
will shorten its life.
At some point battery A will fail and he'll have to buy a new 110Ah
battery which he'll put in parallel with battery B which is now a
year or two old, has had a hard life and is probably only a 60Ah
battery.
And so on....
In addition he'll never actually have 220Ah of storage but something
less.
Two batteries of the same model bought from fresh stock at the same
time and, ideally, the same batch will tend to age in a similar
manner.
MH
Cheers,
Peter
Huh...???
I find since fitting 12v the elect system worked way better..
Power points to existing 12 v...???
vik...
Even boiling an elect jug off batteries through inverter is pulling a massive current.. I found charging things like phones, Ipads etc much better off 12V supply.. 240v is there when hooked up at camping ground.. But we are set up for free camping for weeks on end.. 400 watt solar and [sorry] 5Kw quiet generator ..
If you need to buy 2 new 110Ah battery it would make more $$ sense to buy a 100Ah lithium ferrous battery. It will handle the inverter loads better, recharge faster and last longer for around the same $$ outlay as AGM batteries of an equal quality. The other advantage with lithium ferrous batteries is you can increase the capacity later on without having the throw away the original cells, new and old will work together just fine. As an example, one well know and highly respected A van owner powered his microwave and other 240vac electrical appliances from a single 100Ah lithium ferrous battery and it was still going strong when he sold the vehicle to upgrade to a more off road vehicle.
There is no value in buying old out-dated technology when the new technology will do what you want for around the same price
As far as inverter size/brand/price, depends just what you want to do with it but make sure it is a pure sine wave type, modified sine wave is just not suitable for electronic controlled equipment and will damage it. If you buy a cheapie ebay inverter the capacity required must be greater than the biggest load by around 10%, for example to run a 2,000w kettle you need an inverter with a rated output of at least 2200w, so one advertised as 2,000w - 4,000w won't do the job, the second number is as good as meaningless for practical use and the first number often refers to the input power required at max load, not the mx it can put out continuously. To power a 2,000w kettle you need a 2,500w inverter and this will be big enough to power a microwave or coffee machine or hair dryer..... one at a time and only for as long as the battery capacity lasts of course.
If you want to power a CPAP machine or recharge phones or power the electric blanket, a 300w to 400w inverter will be sufficient.
Hope that helped
T1 Terry
I don't think the same price claim stands up:
Let's compare a 60Ah LiFePO4 battery with a 100Ah AGM battery - there is an argument you'll get a similar amount of energy out of each because of the different recommended maximum depth of discharge:
LiFePO4 = $999
AGM = $280
http://www.ebay.com.au/itm/12V-SSB-FUSION-LITHIUM-ION-POWER-SOLAR-BATTERY-60AH-DEEP-CYCLE-N70ZZ-LFP-12-90-/281703921850?hash=item4196dcb8ba
http://www.ebay.com.au/itm/PDC121000-100AH-750CCA-12-VOLT-BATTERY-DEEP-CYCLE-SOLAR-CARAVAN-AGM-SLA-12V-/221342680201?hash=item33890d4489
:lol: Lithium ferrous is just a way of stopping the confusion with lithium iron and lithium ion looking to be one and the same thing rather than lithium iron (lithium ferrous) being part of the much larger group of lithium technology batteries known as lithium ion due to the ion exchange being their method of electrical energy transfer as apposed to the chemical reaction used in lead acid batteries (flooded cell, AGM, Gel, Lead crystal etc). Li (lithium) Fe (ferrous or iron) P04 (phosphate) LYP is lithium yttrium ferrous phosphate and the improved version of LiFeP04 developed and manufactured by Winston Battery Corporation, Been about for around 5yrs or so and has far better cold tolerance when charging/discharging and increases cycle life, LFP is good but aged technology, LYP is just an improved version better suited to cycling type storage as used in an RV application.
T1 Terry
-- Edited by T1 Terry on Friday 10th of March 2017 04:51:06 PM
I guess I could find links that indicate your AGM batteries are either over priced or under priced, but quality for quality using say Winston LYP cells and Fullriver or Century or Ritar for example, 100Ah of LYP will deliver 100Ah and retain better than 12vdc at even a 100 amp discharge rate (see attached chart) where any of the mentioned brands would be struggling to deliver 100Ah while retaining the 12v at much better than 10 amps from 200Ah capacity.
As far as the recommended discharge limit, you seem keen to extend the lead acid limit below 40% SOC yet ignore the need to retain 12v under load as part of the comparison. I'm quite happy to withdraw my criticism and accept you are correct if you can display that the lead acid battery you mentioned will deliver 60Ah at a rate higher than 5 amps and retain the 12v under load requirement, but keep in mind the 60Ah lithium battery... well an Winston LYP version at any rate, will deliver a lot more than 60Ah if only loaded to 5 amps throughout the test before the loaded voltage drops below 12vdc. Again, refer to the chart, that 100Ah is rated with a 100 amp load, with a 50 amp load it delivers more than the advertised 100Ah so just how much you could get at only a 5 amp load is really an unknown.
Need to compare apples with apples to really see the comparison, any of the lead acid batteries listed above are simply batteries, no BMS or charge control etc, a 100Ah Winston LYP battery strapped with cell links is around the $800 mark if we are going to compare batteries with batteries.
For clarification, the 0.5c means 50% of the advertised capacity as a load in amps (50 amp load from a 100Ah battery) 1C is 100% load etc
T1 Terry
T1-Terry:
I agree with most of what you write - it's just that the two technologies are not compatible price wise with the lithium being about 4 x the cost of a lead acid.
If one requires the specific advantages of lithium then it may be worth paying the extra but for most it will not.
This is the part I can't follow, if the requirement is 100Ah @ 12v min then 200Ah of lead acid min is required, even more if the current draw is greater than 5 amps per 100Ah capacity once the SOC drops below around 60%. With a 100Ah Winston LYP 100Ah battery at around the $800 mark that would mean you were buying deep cycle 100Ah lead acid batteries for under $200 each...... then the quality wouldn't be a fair match and over a 1500cycle use period the lithium would still be like new yet the AGM would be in need of yet another replacement.
Many people confuse cycle use and calendar days, the calendar day life of a lithium battery is as yet unknown, the Mars Rover is still going so we know it must be longer than 10 yrs in a very hostile environment yet used every day if it had a chance to recharge.
Cycle life for a lithium battery is discharged to 2.8v in each cell and recharged to a rested voltage of 3.4v in each cell, lead acid is 700 cycles at a 50% discharge and recharged to 100%, less if you discharge it deeper and more if discharged less. The cut off point for lead acid is 60% of advertised capacity, this actually means less than 10% available before the voltage drops below 12v under load. There are a lot of passed on lead acid batteries out on the road just waiting for the owner to discover just how little capacity is really left in their batteries. A few poor solar days and it's all over as the weak cell gets very deeply discharged and never recovers. A string of 12v batteries only requires one battery to have one of 6 cells fail and that will destroy the other batteries in the series chain if the user doesn't catch it very quickly and remove the connections from the now dead battery. The other batteries will keep trying to recharge it till they are all pulled down to the point where a cell will fail. Brand new batteries can sort of take that sort of punishment, batteries with a bit of capacity loss already can't take it and the weakest cell fails making the battery useless for the purpose intended.
Lithium battery packs properly build and monitored do not suffer this problem, a cell never suddenly drop dead, the death spiral is long and clearly evident for mths if not yrs so the appropriate action can be taken at the owners convenience, not when the battery suddenly didn't do what was asked.
T1 Terry
-- Edited by T1 Terry on Friday 10th of March 2017 07:04:50 PM
Hi
I also think the comparison of the two technologies does not stack up price wise. Terry is a bit one eyed about it as he is an industry expert. That's OK but some balance is necessary for the sake of people not as knowledgeable about the subject.
With Lithium batteries Terry himself has said that you need a 'system' not just a battery, so there is more to buy there. Where as with the old technology LA batteries they are available commonly for a good price, not only premium ones for a premium price, and the associated gear required is also commonly available for a good price.
If you want to spend the money on Lithium that's OK and benefits come with it, but if you just want to "keep the lights on" they do not care what battery the electrons come out of. Your choice but I believe the lithium way will cost considerably more !
Jaahn
:lol: @ x $200 for cheap LA that last for how long? Then another $400 or more due to inflation now equals the cost as the same 100Ah useable from the quality lithium battery that would still be doing what it was bought for, storing energy and releasing it when needed. That how long in both cases depends on some form of battery management.
For those who "just want to keep the lights on" won't have them on for long without some form of battery management. Even a start battery will require some sort of battery management if it's going to last more than a few weeks because it will go flat if not charged. Simply connecting a solar panel or the alternator direct to the battery will over charge it and destroy it, they both need a voltage regulator, the alternator has it built in these days but it is still there, the solar requires a solar regulator to act as the voltage regulator. Lithium batteries are no different, they also require a voltage regulator or they will be destroyed by over charging. The difference is the lead acid battery has no method of measuring cell voltages so any cell in the battery can end up getting over charged resulting in a reduced cycle life, just because you can't see the problem doesn't mean it doesn't exist. Lithium again is no different, it will suffer damage if a cell is over charged, the difference is properly built lithium batteries can have their cell voltage monitored and for a the grand total of $30 plus $5 for the plug and leads to install such a monitor..... but that is a step beyond comparing batteries with batteries, we are now talking about monitoring to extend the batteries life. You can do without the cell monitoring if you want, it's your hard earned $$ that bought the battery so it's up to the user to decide if a bit of insurance is worthwhile or not, the battery really doesn't care.
Any additional costs revolves around reducing the time spent looking after the battery pack, if you want it to look after itself yet still get the long life then you have to pay for the control equipment to do that. If you are happy to do it all yourself then even the $35 can be saved and just use a multi-meter, but I'm sure I could find better things to do with my time than watch batteries 24/7
If you don't want the lights to go out without you expecting it then a battery monitor is required, again, an aid for the user and not mandatory equipment so that can not be included in the price of the battery.
If you are going to compare $$ costs then you do need to compare apples with apples
T1 Terry
Hi
Terry likes to compare our good old Delicious or Pink lady apples with Seckai Ichi apples to make various statements. A bit of a stretch for most supermarket(ebay) shoppers. But who knows how much better the Seckai Ichi apples are as I have never had one ?? Not likely either !
If you can afford the best then spend away, Terry will help you. If not then find advice less biased and add up the costs for yourself ! I do not see many people towing their rigs with RR or even BMW and Audi 4WDs so a budget must be important to some people here.
Jaahn
Lithium is not for the caravan park jumper who never free camps, ever, I can't see why they need a battery at all really.
Lithium is not for the one or two week ends a yr caravan user who doesn't want to use an inverter, lead acid will do that job fine
Lithium is for those who use their RV a lot, they like to camp off grid even in a caravan park because those spots are roomier and further away from the pool and jumping castle. Lithium is for those who do want to use an inverter and who want to move towards 21st century travelling with a few of the comforts from home.
I note it rarely the other half who says they are perfectly happy with roughing it and being restricted in what can be used when, ever thought that might be the reason they are not as keen on travelling as the driver??? Happy wife is a happy life, is parking the van in the yard most of the time a good financial choice when you could be out there enjoying it which was the reason you spent all those $$ in the first place.
T1 Terry
T1 Terry: do you have any kind of commercial interest in lithium batteries?
Yes, my wife became frustrated by the amount of gear I had around the house so she bought a workshop for me to play in, not many blokes have a wife like that eh :lol: I've mentioned else where that I install custom lithium battery systems using as much of the users original equipment as possible by building an interface to adapt just about anything to work well with lithium batteries. Hundreds of systems fitted and all say a similar thing, couldn't live our present lifestyle without them.
I don't want to promote any business interests here, that is not my intention so I won't name the business set up and run by my wife, my interest is in promoting lithium batteries for what they are and trying to quash the myths set up about cost, safety and use that seems to be so wide spread across the internet.
T1 Terry
Here's a spread sheet I worked on to compare AGM to LFP.
This wont be for everybody as I want to have lots of power, but I think the sums stand up for most situations anyway.
Cheers.
I have removed the spredsheet due to it being wrong...
-- Edited by El Gringo on Sunday 12th of March 2017 08:18:58 PM
600Ah @ 24V = 10 @ 120Ah/12V, not 10 @ 160Ah.
And 10 @ 120Ah/12V should cost about $3,850, not $5,500.
And if you are happy to use a Dingo for the Li (plus BMS) then you can also use it for the AGMs (minus BMS), so your control comparison is somewhat biased.
Cheers,
Peter
Perter you missed the very top line of the spreadsheet showing what you need to get for the same (similar) usable amps.
10 x 160a = 300a usable @ 24v (50% DOD)
compared to the LFP at 320a usable. (80% DOD)
As i also mentioned it is for my comparison, the control system is as yet not fully costed, but if anything I have allowed equal amounts dollar wise so there should be no bias there either really.
Yes I have decided on using LFP, but this is what helped convince me.
Cheers.
Opps, I'll take that back, my sums were incorrect....
Well Thanx for that Peter, my brain isn't always to be trusted and I hadn't had anyone check it first for me.
I will attach a revised one though with corrected figures. (Just in case anyone is actually interested.)
Thanx again,
Bernie
ps, apologies to the OP for going off track.
50% DOD is a nominal % for AGMs. There is no damage to go much lower to keep things running, so that 80%/50% DOD comparison is also flawed.
The Li excel for big heavy continuous loads, but not everyone needs that feature.
If AGMs are currently providing the service that you require then the only real benefit to Li is the weight saving plus a life increase that is still to be proven.
They are all "just batteries".
Cheers,
Peter
There is a need for a qualifier as far as depth of discharge goes, both chemistries can be discharged till absolutely no voltage is available but the Li would by far exceed to output obtained from the AGM. The result would be the same though, both batteries would be stuffed.
The best indicator is the advertised battery nom. voltage, 12v for a 12v battery, stands to reason really as that is what was bought, a 12v battery. Now comparing available output at say a 5 amp load per 100Ah of advertised capacity until the loaded voltage dropped below 12v a good AGM battery will pull up at around 50% of the advertised capacity. An LYP battery will deliver more than 100% of its advertised capacity using the same test and that is the only test where the AGM battery stands a ghost of a chance competing head to head. Step up the load used to rate lithium batteries, 50% of the advertised capacity or 50 amps per 100Ah advertised capacity and the LYP battery will deliver all 100% of its advertised capacity before dropping below 12v....... how many Ah can you draw from a 100Ah AGM battery under a 50 amp load before the voltage drops below 12v?
Back to the apples v apples comparison to first decide just how many Ah of AGM batteries are required to match the load/time curve you require, then do a cost comparison. At the moment the cost comparison is being made using a C20 load (5 amps per 100Ah of advertised comparison) so 2 x 100Ah AGM matched up against 100Ah of LYP requires the load to be less than 10 amps to give the AGM batteries a fighting chance..... but then at a 10 amp load the LYP battery would deliver a lot more than 100Ah before it dropped below 12v so the comparison is still not on an even basis is it?
T1 Terry
Who cares? Not me and not anyone I know. Certainly not the OP.
I do know I have been starting the OKA for over 7 years now from a single 120Ah/12V Fullriver AGM. That takes about 400A for up to 45 seconds in the winter. That is not relevant to any discussion here either.
Cheers,
Peter