Triple Battery Systems

[mitchelljames]

Hi all
Im just looking around at battery systems , i was just after some input on what everyone else is using what works well and what to stay away from .. cheers

[Maxhead]

I don't know which systems are better or worse but this is the way I have my system setup. I have 2 batteries under the bonnet and third and fourth in the caravan. This principle would work execly the same if you had the third in the rear of the wagon or ute.

[mitchelljames]

cheers, i originally priced a dual unit from ARB but having looked into to more and advice from friends it seems you can buy everything off ebay a lot cheaper and its not that hard to set up.
Can you ad a solar panel to your set up

[Maxhead]

Yep, I have 125W panel on the caravan which charges the third and fourth battery in the van as the car is disconnected most of the time.If I'm connected and driving the third and fourth batteries gets charged. You can definitely set it up if you want a panel to charge all your batteries

[the evil twin]

I have dual 105 amp hour batteries in my Camper, 100 Amp hour Aux under the bonnet and whatever the cranker is...

100 Watt solar panels charge the Camper and if the vehicle is connected (anderson plug and 2 B&S) will also charge the Aux. Cranker is isolated by a VSR (Redarc)

CTEK battery charger does the same if I am on 240 Volt power

When on the road the Alternator will connect to all 4. Which it won't handle if they are down too far so if my Camper is low I leave the Anderson disconnected for a few hours or at a pinch strap the solar to the camper... haven't had to yet tho

[philfree]

Hi
What i would do if i wanted to run 2 aux batteries one in car other in trailer is use a red arc vsr from main crank battery to the car
aux battery then run a 6 mm twin down to thhe rear trailer battery with a bcdc redarc charger to up the voltage to charge those rear batteries well. and put a cole herse isolator in the van set up so that is connects the 6mm straight to the trailer batteries and isolates the bdcd. for 2 reasons if the bcdc packs up you can bypass it and so that you can have the car hooked to the trailer you can use the car's aux battery for more capacity. This also allows you to just plug it all in the charger turns its self on the main aux battery is getting charged and
no matter how flat the trailer batterys are the charger will only draw it's 20 amps with any lateish model patrol alternator can easly maintain.

[philfree]

Just a note if any one is looking to use a 24volt car to charge a 12volt aux batteries the bcdc charger is good for that to

[the evil twin]

Hi
What i would do if i wanted to run 2 aux batteries one in car other in trailer is use a red arc vsr from main crank battery to the car
aux battery then run a 6 mm twin down to thhe rear trailer battery with a bcdc redarc charger to up the voltage to charge those rear batteries well. and put a cole herse isolator in the van set up so that is connects the 6mm straight to the trailer batteries and isolates the bdcd. for 2 reasons if the bcdc packs up you can bypass it and so that you can have the car hooked to the trailer you can use the car's aux battery for more capacity. This also allows you to just plug it all in the charger turns its self on the main aux battery is getting charged and
no matter how flat the trailer batterys are the charger will only draw it's 20 amps with any lateish model patrol alternator can easly maintain.

Hiya Philfree... That'll certainly work .

I have a Cole Hersee set up on the Camper so it will run Battery 1, Battery 2, Both, Neither or Vehicle Supply. No Cole Hersee switch on the Solar as no point because the current is so low.

No need for a DC/DC converter as Voltage drop is neglible and the Batteries will take the full Charge acceptance Current and not be limited by the Converter Output. Use an MPPT Solar Reg and no need for a DC/DC Converter there either.

The only reason to use a DC/DC jobbie is if you want to go light on the wiring gauge and accept a significantly slower recharge which can be advantageous for Vans certainly.

The OP didn't specify... but if he is running the third battery in the back of his truck then I def wouldn't use a DC/DC converter. Go 2 B&S or heavier and that way you can use the full output of the third battery back to Aux. Put in a Converter and you can't because of the lighter gauge wiring.

If it gets desperate I can use my Camper Batteries to start my vehicle or power my Winch just at the flick of a switch

[philfree]

well sure both will work the reasoning behind doing it that way was because the guy up said it can overload his alternator with the charger it will limit it and their for not overload the alternator you could still run 2 bns for the back up like you said. The battery people i talk to who only sell batteries don't sell chargers say that a car alternator only maintains batteries not good for batteries that are run flat they reccomend proper chargeing of the batteries eg smart charger to make them last longer with more capacity.

[the evil twin]

The guy up was me... The issue that happens is that a 90 Amp alternator doesn't put out 90 amps across the whole charge curve so you have to "idle up" if camped or there are the other normal vehicle loads to consider as well if driving.

Like everything else it is always a compromise and usually depends on what the person is using the Battery Storeage for that determines the best bits of kit. I want "any" battery to do "any" task, Winch, Start, Camper Power, etc ('cept the cranker supplying aux load) so a DC/DC is no good for me. For a Caravan that configuration isn't usually viable or necessary so a DC/DC converter is perfect

The advice you got from the Battery people is 100% correct as well. Unfortunately that can be a rarity at times.