If planning twin batteries you need to consider the following options...
1. If planning to connect two batteries in parallel (positive to positive, negative to negative) you must ensure that both batteries are identical in every respect...brand, model, age, discharge history. Also they need to be located very close and connected with short as possible very heavy gauge cables (like starter motor gauge). You will need to start with brand new batteries to meet the "identical" criteria. I recently read in a magazine a case of a battery destroying itself as a result of a "thermal runaway" condition where dissimilar batteries were "paralleled". I personally do not like this configuration and can call on personal and costly (to my employer at the time, not a good look) experience of reduced battery life despite meeting these conditions. If one battery fails you will need to replace both batteries. Also if one fails and you're not aware of this the other probably will soon follow.
2. A preferred twin battery set up is to use two 6 volt batteries connected in series. Again the batteries should be identical but other aspects of the installation are not as critical. This configuration will not shorten the life of the batteries. If one battery prematurely fails, depending on the circumstances of the failure, you shouldn't need to replace the other one.
Note that two 200 amp hour 6 volt batteries will give you a total capacity of 200 amp hours.... not 400 amp hours. A 200 amp hour 6 volt battery is a similar physical size to a 100 amp hour 12 volt battery.
(Series connection means connecting the negative wire to the negative terminal of one battery the positive of that battery to the negative of the second battery and the positive wire to the positive of the second battery.)
3. The least critical set up is two 12 volt batteries with a changeover switch (available at marine and caravan shops) and use them one at a time. Location and cable sizes are less critical and dissimilar batteries can be used.
I do not own a generator but it's my understanding that it is better to charge batteries with a battery charger connected to the 240v ac output rather than using the 12v output.
-- Edited by jimricho on Wednesday 9th of June 2010 07:46:24 AM
Hi All, Jimricho, That is good advice, The only thing I would add. Is if dollars can be found fit sola as well. They are good when fitted properly and will save you a LOT of money..gennys are a good back up.and yes better to have a good batt. charger than use the 12 volt out put from the genny.. Been useing sola since 94 and they still work well.. When bush camping ,we can go for days with out running the genny, and we have a 12 volt comp.fridge.. Setting up always cost a little bit, but done right its worth it..good luck..Bob n Bev
__________________
Land Rover Discovery Chipped TD5 Manual ,Air Springs, Anti Sway. T.C. Auto level. Van, Roadstar 21.6 Voyager 4000 all sola powered.
I don't have solar either but if I start doing more extended bush camping that will be the way I'll go. That's not meant to claim that solar is somehow better than genny as that depends on one's individual situation.
I don't have solar either but if I start doing more extended bush camping that will be the way I'll go. That's not meant to claim that solar is somehow better than genny as that depends on one's individual situation.
Dead right jimricho but solar is silent, and costs nothing to run.
-- Edited by JRH on Wednesday 9th of June 2010 05:17:23 PM
__________________
If I don't get there today, I'll get there tomorrow or the day after.
John & Irona..........Rockingham Western Australia
I think we wandered slightly away from your question although all relevant stuff
You ask the question "battery OR Solar" implying that these are alternatives. A solar panel requires a charge regulator AND a battery to charge up while there is (useful) sunlight on the panel. This battery should be a separate additional battery to your vehicle's normal (starting) battery and is often referred to as the "house" battery. The reference above to a twin battery installation refers to the house battery(s) only and does not include the starting battery.
It is possible (and quite common) to also connect a 240v mains powered charger to the house battery for when "ground" (mains) power is available. I strongly recommend using a good quality multi-stage "smart" charger for this purpose. It is also common to recharge the house battery from the vehicle's alternator but a special isolating thingy called a (amongst other names) voltage sensitive relay (VSR) needs to be installed to ensure that the vehicle's own battery gets charging priority. There are some 12v dc - 12v dc battery chargers coming onto the market now and are worth considering instead of the VSR.
If you're not "au fait" with matters 12v electrical I suggest you seek "professional" help with the installation and preferably from someone familiar with caravan/motor home electrics and deep cycle batteries.
Note also that any 240v mains wiring must be done by a licensed electrical contractor.
If installing a 3-way fridge I suggest you not wire the 12v dc element to the house battery but to the vehicle's battery instead via a relay so that it only operates (when switched to 12v) when the engine is running. Other times you run it on gas or mains power when available.
Not being of an electrical persuasion, I leave that to the people who are trained to install the package and I charge the batteries through the onboard charger using a pure sinewave genie
This is similar to what I mean
-- Edited by goinsoon on Wednesday 9th of June 2010 07:30:13 PM
That setup is not mine but similar and I use an inverter genie as I just plug it into the caravan to charge the batteries, works fine as it is pure sinewave
__________________
Goinsoon
I dont suffer from insanity; I enjoy every minute of it.
so with solar , can i run my tv,lights and laptop at night ? ie when not at a cp ?
Milo, with enough Panels, and Batteries for Power storage, you can run a whole house, with all the usual appliances. Lots of people are running Laptops, Fridges, Lights, TV's, DVD Players, etc. in Motorhomes all around the country. You just have to find out what size and number of Panels, and how many Batteries you need, for what you want to run.
Brickies makes a valid point about keeping it simple.
Ask yourself this.....Do you really need to use the high current luxuries when free/bush camping such as microwave, electric jug/kettle, toaster, hair dryer, electric heater, etc. How much TV/DVD watching do you intend to do?
My main load when bush camping is a "Bushman" fridge (similar to Engel/Waeco etc) that's installed in the vehicle and powered from an auxiliary 50 ah battery. The battery size is limited by the physical space available. I also have a 30ah jump starter for a back-up for the fridge (or the van) and I use a Ctek 3.8 amp charger to recharge this rather than its internal charger. I have a Ctek 7 amp charger installed in the car that powers the Bushman and recharges the battery when connected to "ground" power.
My van is fitted with a 55ah Optima Red Top that's over 8 years old and was tested about a year ago and still had most of it's ah capacity, down slightly, but my test set up was at the c10 rate not the more usual c20 rate. Yes I know, a Red Top is a starting battery but during its life its been a car battery, a boat battery, and now a deep cycle battery. I can get several days out this battery and my only charging arrangement is when I'm on "ground" power. I can reconfigure a voltage booster currently fitted to the 3 way fridge to charge the van battery on the move but so far have not needed to do this. As alluded to earlier, if I find myself doing more extended bush camping I'll consider solar, mainly for the Bushman
Small LCD TVs draw much less power than the older tube type units, mine draws 3.3 amps directly from 12 volts, no inverter needed. The best way to recharge a Laptop when 240v power is not available is by using a 12v laptop power supply rather than an inverter. These cost significantly less than a pure sine wave inverter. (use a cheapie inverter at your own risk, we've been there before). Those with CPAP machines will need to consider their power requirements, this subject has been previously visited on this forum too.
Another power saving is to consider installing LED lighting.
A couple of sites worth checking for more info....
When using my campertrailer I have a 120 amp hour deep cycle battery and a 80watt solar panel regulated...for lighting and running my 40lt waeco.....I'm getting a caravan and will be using the solar panel for it..it wont be fixed to the van....as I like chasing the sun...they dont work well in the shade.
also do solar pannels get much damage from heavty rain and hail? and can they be purmantly mounted on the roof with out blowing off at 100ks??
My understanding is, that they're built to withstand most weather conditions Milo, and if they're attatched properly, there is no way they will fly off the roof.
If I've got it wrong, some-one will let us know, Cheers, Sheba.
Hi All, We live in the best part of the world ,Right.. so one should not complain about a thing..even noisy gennys..I carry two a 1kva..and a 2.6 kva..And use both at times. both inverter type.and very quite.. As well as that I have on the roof 2 sola panels with the out put of 420 watts.. in the batt. 2 ,120 amph AGMs..And when we are at a lonly beach and away from other people a Wind genny that has put out over 35 amps at 12 volts..Very frighting to see the blades at that speed..Any how dogs ,we had a little darling once travled with us for over 14 years..Now she has gone its much easier to go places and do things. Yes I would have her back in a heart beat..But would not have another..The poor guy that asked if sola is better than gennys..Yes sola is better if set up right ..Gennys are better if you just stay over night here and there , and CP are your thing..Its just one of them things, Its up to you..But dont argue over it ,Just do it..And Smile while you do..to easy..There is just one real problem and thats getting old to quick...So dont wast a min..Bob N Bev
__________________
Land Rover Discovery Chipped TD5 Manual ,Air Springs, Anti Sway. T.C. Auto level. Van, Roadstar 21.6 Voyager 4000 all sola powered.
Check out Sidewinder up at Qld -- they have a online store with heaps of info on their web site.
depends where you travel if your solar or genny --- solar can be pretty useless down in the southern states during the cooler months .
solar panels are toughned glass, hence near unbreakable
my own set up is both, a Honda 20ui Genny , along with a fixed flat panel and a foldable panel ---- useing a sidewinder battery pack in vechile and batteries in camper along with inverters
would not even attempt to use electric toaster or jug unlless hooked up to powered site -- far to much draw --- better to use gas or camp fire for these.
cheres
Coyotte
__________________
BOWRAL --- Southern Highlands -- N.S.W
Love this road -- Love this life-- It's in my blood --It's in my soul
I'm about to investergate what size sola panel, most suggest 120watt free standing with a 3000 tonne boat chain with 12 padlocks. I wondered about parking in the shade how the panel would work. They say the free standing panels are cheaper now & all you have to do is fit anAndreson plug back directly to the battery in the van. With your current set up how long can you stay away from 240v.
I have 2 x 100amp batteries and 2 x 80 solar panels. 3 way fridge I run on gas when camping.
With this set up you cannot use high end power items like Microwaves, toasters or electric kettles, However, I still watch TV each night and by the time the sun goes down the next day the batteries are fully charged
I also have a 2kva gennie for emergencies and have used it once in 2 years when I had a week of rain whilst camped in my brothers front yard...without access to power (2 acres property)