We have 2 x 100a/hr AGM batteries in our caravan. They are dead! Time to replace them...we did get 4yrs out of them so to be expected!

My question is...has anyone bought batteries off eBay? And if so, were they good? Did they last you a decent length of time?

We are thinking of upgrading to 2 x 140a/hrs AGM. Our old configuration was not quite enough to run our caravan and a Waeco fridge.

Any advice greatly appreciated. Thanks

Kebbin wrote:

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Kickass or Australian direct batteries are overrated, light for there Ah buyer beware!

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:lol: They don't make light weight lead and it takes 30kg of lead to make a 100Ah C20 rated deep cycle battery. Add the weight of the plastic case and the electrolyte and a 100Ah deep cycle battery weighs 32kg, no way around it. If they load test at C100 (discharged over 100 hrs not 20 hrs) then they get a higher number of Ah before the battery is absolutely flat and quite possibly stuffed, but the numbers look good if you don't know what you are looking at

Often wondered just how much you could get out of a Winston 100Ah lithium battery at a C20 rate, the standard used by quality lead acid battery makes, the standard for quality lithium batteries is 0.5CA or fully discharged over 2 hrs not 20 hrs.

You really need to understand just how much capacity you are buying before you do the cost comparison, so the test really needs to be at the same load in amps for the same length of time till the same voltage is reached while under load. Using an end of test voltage of 10.5 is rather meaningless, especially if they don't mention if it's rested or under load. If you look here  http://www.fullriverbattery.com/product/batteries/DC105-12 you can see that after roughly 10hrs the C20 load of only 5.3 amps drops the battery down to 12v or less, yet the Winston lithium with a load of 50 amps (10 times as much) still holds above 12v for more than the 2 hr test time it takes to deliver the full 100Ah advertised capacity .... how long could it deliver a 5.3 amp load before it dropped below 12v?

For the sake of comparison, look at the 1CA load (105 amps from a 105Ah battery) in the Full River chart and where it drops below 12v line and divide the capacity by the number of mins or the mins into hrs to see the real capacity under that load.

Now look at the Winston 100Ah cell chart at the  same 1CA load and have a look at where it drops below the 3v mark (4 x 3v = 12v for a 12v battery) now you get a better idea of just how good one battery is compared to the other, which one actually delivers the full 100Ah even under very high loads.

T1 Terry

T1 Terry wrote:

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For the sake of comparison, look at the 1CA load (105 amps from a 105Ah battery) in the Full River chart and where it drops below 12v line and divide the capacity by the number of mins or the mins into hrs to see the real capacity under that load.

Now look at the Winston 100Ah cell chart at the  same 1CA load and have a look at where it drops below the 3v mark (4 x 3v = 12v for a 12v battery) now you get a better idea of just how good one battery is compared to the other, which one actually delivers the full 100Ah even under very high loads.

 

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Terry a 1CA comparison for 99% of RV battery users is stupid and misleading.

Forever the one eyed salesman. Can't help yourself can you?

Cheers,

Peter

I agree...they should have lasted longer. We put the caravan on a sales yard here in Townsville because we were thinking of selling as we werent using caravan. The dickhead at the caravan place disconnected our batteries...despite the fact we have solar panels on the roof! My partner took them into work (bus company) and tested them and tried charging them in some heavy duty charger...no joy! 

Thanks everyone for your feedback.....will probably buy from a store on eBay.

Peter_n_Margaret wrote:

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T1 Terry wrote:

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For the sake of comparison, look at the 1CA load (105 amps from a 105Ah battery) in the Full River chart and where it drops below 12v line and divide the capacity by the number of mins or the mins into hrs to see the real capacity under that load.

Now look at the Winston 100Ah cell chart at the  same 1CA load and have a look at where it drops below the 3v mark (4 x 3v = 12v for a 12v battery) now you get a better idea of just how good one battery is compared to the other, which one actually delivers the full 100Ah even under very high loads.

 

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Terry a 1CA comparison for 99% of RV battery users is stupid and misleading.

Forever the one eyed salesman. Can't help yourself can you?

Cheers,

Peter

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Can't help yourself can you Peter, always been on the attack if it isn't a product you are using at the moment  Try reading the first few words of the bit you quoted and the topic of the thread, can you see any relevance there? Now read through your post, was it informative based or attack based? The fact that you don't think you could use 100% of the batteries capacity or a load greater than 5 amps per 100Ah capacity at any time doesn't mean you represent 99% of the RV community, so why is it stupid and misleading?

By offering a comparison the reader can make their own decision if the capability of a certain chemistry battery would better suit their needs, then add in the weight factor, cycle life and speed to recharge etc and determine for themselves which chemistry would better suit their needs. What makes you think something that doesn't suit you at the moment wouldn't suit anyone in an RV?

 T1 Terry   

Gday...

Terry, your knowledge of your products and their applications are renowned and appreciated.

However, too often when some asks the time you provide a detailed, albeit informed, description - with diagrams - of how to design a watch.

But keep sharing the info ... there are some who will understand it even if I don't.

cheers - John

rockylizard wrote:

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Gday...

Terry, your knowledge of your products and their applications are renowned and appreciated.

However, too often when some asks the time you provide a detailed, albeit informed, description - with diagrams - of how to design a watch.

But keep sharing the info ... there are some who will understand it even if I don't.

cheers - John

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Thanks John, never sure if I'm doing the right thing or not, I only ever seem to hear from the minority that want to attack anything that they don't want to understand for what ever reason

T1 Terry 

rockylizard wrote:

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Gday...

Terry, your knowledge of your products and their applications are renowned and appreciated.

However, too often when some asks the time you provide a detailed, albeit informed, description - with diagrams - of how to design a watch.

But keep sharing the info ... there are some who will understand it even if I don't.

cheers - John

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 Hi 

An old saying; "Fools rush in where angels fear to tread" but here goes 

The way i see it John above has put his finger on one side of the problem with Terrys answers. Perhaps Peter has also. I see it as answering the wrong question all the time. Everyone knows lithium technology is better and will take over. 

The question that a lot of people want to have answered is simple really. How much do I have to spend today to get my simple basic system to work reliably. EG buffy61 , not a technical dissertation about discharging at C1 (I hear people asking; WTF is that ???). There were lots of answers about the life he should have expected and reasons to explore to improve it. Good !   

So there seems to be great  mystery about the cost of lithium. I posted some costs from a supplier that I knew about, but Terry had a put down for that.  On another thread another poster said he had fitted 350Ahr of lithium and he was satisified following a Terry post, but no costings ?? That is what people want to know. Not a whole of life dodgey comparison with a genny thrown in for more cost padding. 

So Terry if you want to get brownie points from the punters put up some LI costs when someone want to replace some LA batteries. IMHO.

If someone want to set up an ultimate system in their rig then contact Terry direct and take the cheque book. 

Jaahn    

Here is another link to a LI site, that I have no association with except having used them and they put their prices there.  https://www.lfp.net.au/shop 

PS Terry I do understand C1 so no need to explain it thanks 

Good post Jaahn

So Terry if you want to get brownie points from the punters put up some LI costs when someone want to replace some LA batteries. IMHO.

Yep.

I will be replacing my 8 1/2 year old 460Ah of AGMs in the near future (3-6 months?). I have a quoted price of $1200 for 500Ah of good quality replacements. I have a PL60 controller which is quite suitable for the 600W of solar, the hold down brackets are all in place, so it is a simple "drop in" replacement. They can be left un-seen and un-monitored for 6 months or more at a time without attention and the solar simply "takes care of them". 

Terry, how much to install a 400Ah lithium pack, complete with fully automatic BMS (set and forget)?  I would love to give you the business. Seriously.

Cheers,

Peter

Between a rock and a hard place there Jaahn. If I post prices I get accused of using the place as an advertising spot, just been jabbed with the salesman line a few posts back. I give a price for a basic battery system and then I get attacked for false advertising or something because I won't fit a full bells and whistles system for the same cost as well as the other 50 things they want done at the same time. Trust me, we have had few of them and one that still owes us quite a bit because she thought the other weeks worth of work she wanted done as well should have been thrown in like installing a household fridge in place of the 3 way and rebuilding half the cupboards and wiring so the microwave could be retained

If I quote a price for a system that suits one customer it might not do what the next one wants or be a heap more than they want so a waste of money.

We don't install drop in systems, we try to fix the mess people end up with after they bought a drop in set up but it always ends up as a compromise and the end cost is way more than the original custom set up would have cost and doesn't have the same technical and product back up.

No doubt this will be seen as product promotion and I'll get attacked for that, seems no matter what I do here I'm not doing it right, I don't promote the business name here for that very reason, but I do offer help to anyone who asks either on the open forum or via PM, should I stop doing that?

T1 Terry 

Peter_n_Margaret wrote:

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Good post Jaahn

So Terry if you want to get brownie points from the punters put up some LI costs when someone want to replace some LA batteries. IMHO.

Yep.

I will be replacing my 8 1/2 year old 460Ah of AGMs in the near future (3-6 months?). I have a quoted price of $1200 for 500Ah of good quality replacements. I have a PL60 controller which is quite suitable for the 600W of solar, the hold down brackets are all in place, so it is a simple "drop in" replacement. They can be left un-seen and un-monitored for 6 months or more at a time without attention and the solar simply "takes care of them". 

Terry, how much to install a 400Ah lithium pack, complete with fully automatic BMS (set and forget)?  I would love to give you the business. Seriously.

Cheers,

Peter

-- Edited by Peter_n_Margaret on Friday 3rd of August 2018 03:45:29 PM

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I'm not quite sure what you are asking here, you quote a price for 500Ah lead acid drop in but ask for the price of an installed 400Ah system that would give a lot more useable storage than the 500Ah lead acid in both immediately useable energy and cycle life so deliverable energy per $$ for the life of the battery pack.

Basically lithium cells packed and strapped ready for use costs some where around $1,000 per advertised 100Ah, so $4,000 for 400Ah. The battery management cost roughly $780, depends just what needs to be controlled and how many different control methods would be required. For instance, anything with separate voltage sensing can be controlled by a single module in the control package, no need for a module for each of them as the number any single module can control is open ended. In your case you don't have any mains power plug in charging so a module to control that would be a waste of money for you. You don't use a DC to DC charger from what I understand so you don't need any sort of control for that, although most of the good ones can be simply controlled by the base lithium control system. If you already have a Victron BMV or a suitable battery monitoring system you don't need one of those, if all the wiring and fuses you have now are good enough to do the job then there is no additional costs there .... can you see why a one set up suits all never seems to suit anyone? 

If you really want a better quote, drop me a PM or email and I'll pass it on to Margaret, she does prices, I'm just the unpaid worker who's thrashed red headed stepchild

T1 Terry

Terry said....

. some where around $1,000 per advertised 100Ah, so $4,000 for 400Ah. The battery management cost roughly $780,.........You don't use a DC to DC charger...... If you already have a Victron BMV or a suitable battery monitoring system you don't need one of those,

Thanks.

So. $4,780 for 400Ah with BMS?

I don't use a DC-DC charger, but I do charge direct from the alternator via a 200A VSR if solar is poor and I do use the house batteries to crank the engine (again, via the VSR) if it is very cold (no glow plugs in the Perkins). I would expect to be able to maintain those capabilities.

EDIT... The PL60 sees and records those currents, both in and out via an existing 200A shunt and PLS.

I don't have a Victron BMV because the PL60 provides complete in/out/SOC information. Why would I need anything else?

Does that information change what I need?

Is that lithium BMS set and forget?

Cheers,

Peter

Gee Terry that did not seem so hard. I do not think you will be dammed for that post 

We all know(or should know) that the devil is in the details for an accurate price. But that gives people something to think about price wise.

Jaahn

Jaahn wrote:

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Gee Terry that did not seem so hard. I do not think you will be dammed for that post 

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Certainly not by me.

Cheers,

Peter

buffy61 wrote:

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We are thinking of upgrading to 2 x 140a/hrs AGM. Our old configuration was not quite enough to run our caravan and a Waeco fridge.

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 Buffy, maybe another side track, but apart from the fridge, do you have any other constant loads?

If not, I would consider that 200Ah of batteries should be quite sufficient for your needs. Maybe rather than adding more batteries you should add more solar (which will last 20+ years).

Batteries only need to last while the solar is not keeping up and mostly that is just over night (which is probably 25Ah +/-) plus some extra capacity for the no sun days when the solar output is lower than the usage. 

How much solar do you have now?

Cheers,

Peter

Peter_n_Margaret wrote:

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Terry said....

. some where around $1,000 per advertised 100Ah, so $4,000 for 400Ah. The battery management cost roughly $780,.........You don't use a DC to DC charger...... If you already have a Victron BMV or a suitable battery monitoring system you don't need one of those,

Thanks.

So. $4,780 for 400Ah with BMS?

I don't use a DC-DC charger, but I do charge direct from the alternator via a 200A VSR if solar is poor and I do use the house batteries to crank the engine (again, via the VSR) if it is very cold (no glow plugs in the Perkins). I would expect to be able to maintain those capabilities.

EDIT... The PL60 sees and records those currents, both in and out via an existing 200A shunt and PLS.

I don't have a Victron BMV because the PL60 provides complete in/out/SOC information. Why would I need anything else?

Does that information change what I need?

Is that lithium BMS set and forget?

Cheers,

Peter

 

-- Edited by Peter_n_Margaret on Friday 3rd of August 2018 04:32:57 PM

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Not completely set and forget, it will alarm if things need attention like low state of charge or battery voltage, excessively low cell voltage, excessively high cell voltage, high battery voltage. It will automatically disconnect the battery if these alarms are ignored or you just weren't there to respond and stays disconnected till manually reset. We chose this method because we considered it better the owner knows there is a problem that needs attention rather than being hidden unless you probed for it and the owner wouldn't know if the fridge had been off for a period of time so they could check the ice cubes in the freezer bag to see if their has been a defrost.

As far as more information required, probably not if you have separate voltage sensing wires to the PL60 and you are using no other auto charging devices. I assume the VSR is manually controlled so it was only turned on when needed to save the alternator from overheating. If the cables etc can handle 200 amps with little voltage drop then 200 amps or more will flow into the lithium battery if the voltage difference is there and that can be quite a load for any alternator.

As far as the Plasmatronics shunt, the limit is 200 amps unless you add more shunts and paralleling shunt adaptors and the controllers have no Peukert Factor nor charge efficiency adjustment like the Victron BMV does and these are different between different battery chemistries. I believe you know Lesley & Eric that swapped over to lithium batteries maybe 5 yrs or so back, they had issues with the Plasmatronics getting out of phase with remaining battery capacity and often reading up to 125% SOC due to these error factors, so for the $300 for a Victron BMV it seemed to be a good investment.

Most that have the Plasmatronics shunt set up already now use it to record the charging only from all devices so they know just how much is coming in, the Victron only shows what is going to or from the battery so what is used by the loads directly is not shown. The Plasmatronics history is a bonus as well because daily min and max battery voltage is recorded along with charging and even that is broken down into internal (solar throughput) and external that could be battery to battery or from a mains charger or even a wind turbine if someone wants to use one of those. Mostly for those who want to know a lot of info. Those that just want to flick the switch and the light comes on etc have no need for such things, again, a system designed to suit the user. There is even a feature that can record and produce a graph of each cell voltage 24/7 for a 7 day period if that sort of stuff interests the user or if trying to fault find a problem, it allows the battery to be ruled out or pin-point just where to look.

Again, this wasn't intended as a promotional post but I might have got a tad carried away

T1 Terry

Thanks Terry...

 It will automatically disconnect the battery if these alarms are ignored....

That seems OK for the house battery, but what sort of disconnect do you use - it would need to be 300A capable - and I presume there would be no risk in not attending to the problem for some months - is that acceptable and safe?

It does raise another question too.... when we go away for extended periods, I bridge the VSR (which I leave open, because it consumes power) to keep the crank battery in parallel with the house battery and I also add the crank from Margaret's shopping trolley to the mix so they are all kept topped up and ready to go for when we come home. The vehicles are in a shed with some clear roof panels and that is enough for the solar on the OKA to do its job.

Any other issues there?

I assume the VSR is manually controlled so it was only turned on when needed to save the alternator from overheating. If the cables etc can handle 200 amps with little voltage drop then 200 amps or more will flow into the lithium battery if the voltage difference is there and that can be quite a load for any alternator.

I usually manually control the alternator, but will generally leave it charging until the house voltage equals the alternator voltage (14.3V) at which point the alternator switches off, the charge light on the OKA comes on and the tacho stops working. At that point I manually open the VSR. The alternator is 85A and I typically start with 70A (according to the PL60) to the house batteries (via a 70mm2 cable). I have never had any alternator overheating issues.

As far as the Plasmatronics shunt, the limit is 200 amps unless you add more shunts and paralleling shunt adaptors and the controllers have no Peukert Factor nor charge efficiency adjustment like the Victron BMV does and these are different between different battery chemistries. I believe you know Lesley & Eric that swapped over to lithium batteries maybe 5 yrs or so back, they had issues with the Plasmatronics getting out of phase with remaining battery capacity and often reading up to 125% SOC due to these error factors, so for the $300for a Victron BMV it seemed to be a good investment.

Not sure what you are saying here as to whether I would need the Victron BMS, or not.  I would not be keen to add it, but I would not want to loose any more of the accuracy of the PL60 SOC readout, which I find to be quite adequate.

Most that have the Plasmatronics shunt set up already now use it to record the charging only from all devices so they know just how much is coming in, the Victron only shows what is going to or from the battery so what is used by the loads directly is not shown.

My current 200A shunt shows both incoming and out going power which is counted by the PL60 as external load or charge.

Cheers,

Peter

Peter_n_Margaret wrote:

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Thanks Terry...

 It will automatically disconnect the battery if these alarms are ignored....

[quote= That seems OK for the house battery, but what sort of disconnect do you use - it would need to be 300A capable - and I presume there would be no risk in not attending to the problem for some months - is that acceptable and safe?

It does raise another question too.... when we go away for extended periods, I bridge the VSR (which I leave open, because it consumes power) to keep the crank battery in parallel with the house battery and I also add the crank from Margaret's shopping trolley to the mix so they are all kept topped up and ready to go for when we come home. The vehicles are in a shed with some clear roof panels and that is enough for the solar on the OKA to do its job. ]

Possibly getting a bit complicated for this thread, but it can reasonably easily set up to disconnect the lithium house battery to protect it while leaving the start battery connected so it remains charged via the solar, lithium batteries don't like to be held at a float voltage for extended periods without ever seeing a load because it can damage them. Simply dropping into float mode during the day and then under load over night to run say a fridge etc and then solar recharge the next day and again returning to float voltage is a completely different thing that some people can't seem to get their head around, lithium batteries excel at this type of work. Basically, they love to work and work hard compared to the way lead acid batteries are treated, they don't like being treated like pets and the whole definition of cycle life is different between lead acid and lithium .... I've started getting carried away again eh

The battery isolation can handle a constant 350 amps at up to 800v but the 100,000 cycle life starts to drop off over the 24v mark, 800v @ 350 amps only has a cycle life of around 150 cycles but that is way outside anything likely to be experienced in an RV. Current carrying capacity over time start to drop off at around the 450 amp mark from 10,000 seconds down to 1,000 secs at around the 500 amp mark and 20 secs at around the 2,000 amp mark, but that is mostly due to cable size and heat rise.

Any other issues there?

I assume the VSR is manually controlled so it was only turned on when needed to save the alternator from overheating. If the cables etc can handle 200 amps with little voltage drop then 200 amps or more will flow into the lithium battery if the voltage difference is there and that can be quite a load for any alternator.

[quote= I usually manually control the alternator, but will generally leave it charging until the house voltage equals the alternator voltage (14.3V) at which point the alternator switches off, the charge light on the OKA comes on and the tacho stops working. At that point I manually open the VSR. The alternator is 85A and I typically start with 70A (according to the PL60) to the house batteries (via a 70mm2 cable). I have never had any alternator overheating issues.]

70mmsq cables will carry a lot more than 70 amps without a voltage drop and lithium batteries do not have the high internal resistance that lead acid batteries do, so until the voltage equalises a lot of current will flow from one battery to the other meaning the alternator will be at max output while this is happening and this will overheat an alternator not built with additional fans and over size heat sinks to get rid of the heat ... but your call, you turn it off when ever you want. There would need to be an interrupt control available to the lithium battery control system because 14.3v is way too high for a 12v lithium battery if you want a long service life ... all fairly easily buolt into the custom designed/built system, but again, another example of one design not fitting all applications.

 

As far as the Plasmatronics shunt, the limit is 200 amps unless you add more shunts and paralleling shunt adaptors and the controllers have no Peukert Factor nor charge efficiency adjustment like the Victron BMV does and these are different between different battery chemistries. I believe you know Lesley & Eric that swapped over to lithium batteries maybe 5 yrs or so back, they had issues with the Plasmatronics getting out of phase with remaining battery capacity and often reading up to 125% SOC due to these error factors, so for the $300for a Victron BMV it seemed to be a good investment.

Not sure what you are saying here as to whether I would need the Victron BMS, or not.  I would not be keen to add it, but I would not want to loose any more of the accuracy of the PL60 SOC readout, which I find to be quite adequate.

Most that have the Plasmatronics shunt set up already now use it to record the charging only from all devices so they know just how much is coming in, the Victron only shows what is going to or from the battery so what is used by the loads directly is not shown.

My current 200A shunt shows both incoming and out going power which is counted by the PL60 as external load or charge.

Cheers,

Peter

-- Edited by Peter_n_Margaret on Saturday 4th of August 2018 03:12:32 PM

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 As far as the Plasmatronics shunt and the 200 amp capacity, how does it handle the 300 amps plus required for the start assist? Even close to running at the 200 amp upper limit some heat is generated and this effects the shunt accuracy as the use of an inverter larger than 2,000w has shown in the past, but if you are happy with the accuracy that it provides then there is no need to add another battery monitoring system. It can always be fitted later anyway so not a serious stumbling block.

T1 Terry