series or parallel batteries

**monster** · #1 22 Nov 2008

just about to wire up my batteries but do i series or parallel them. both 125AH and going to be on a solar system, which is the best way.
1. series 24v 125AH
2. parallel 12v 250AH
solar panels 164 W
any ideas
cheers
dave

**silver G** · #2 22 Nov 2008

Depends which vehicle you have. If your system is 12 volt then parallel.

**monster** · #3 22 Nov 2008

Got a truck- took all the old electrical system out as it was like spag. junction- way too complicated and old!
Have now bought 4x 125ah batteries, plan to use 2 as auxillary which will be charged by engine and 2 for our solar.
All our equipment is 12volt apart from our shurflo pump.
Now trying to work out how the hell to set it all together on a very tight budget!- Usual overlander predicament!! Ha ha
Cheers Dave

**silver G** · #4 22 Nov 2008

Quote:

Originally Posted by silver G

Depends which vehicle you have. If your system is 12 volt then parallel.

Depending on the truck you could well have a 24 volt system
ie - alternator, glowplugs and lighting.

Having all your ancils running off a 12 volt system is probably best but you will have to work out how to charge it off 24 volts if that's the alternator you have.

I hate electrics BTW and still waiting for someone to explain why current doesn't flow out of the negative terminal

and I can live in peace with my battery change over switch

**monster** · #5 22 Nov 2008

hi yep 24v charger but only charges one set of batteries (2x 125AH) which we use for emergency if no sun and staying for a long time in one place,
other 2x 125ah will be charged with solar so seperate system and 12v and run lights fridge water filter and heater.
cheers
dave

**silver G** · #6 22 Nov 2008

I think I would go with 12 volt then - lots of cheap 12volt halogen and led stuff around for lighting, fridges, car stereos, leads for laptops etc. I would try to run as much as possible off 12 volts and avoid running through inverters - they are very inefficient.

**ivanll** · #7 23 Nov 2008

If the vehicle (Truck) is 24volt keep it that way.(2x12V in series)
Keep it completely separate from the house battery system.
If the truck have a 24V Cig. lighter remove it. It will eliminate future mishaps.
Make the house electrical system 12Volt. (2X12V in paralell)
You mentioned solar panels 164 W.
Panels (plural as in 2 or more)
If it is 2 x 12Volt 80 Watt panels, connect them in paralell for the house battery via a good solar regulator
If it is a single 23.6 Volt 164 W panel then do not connect it to the 12 volt house battery.

**monster** · #8 23 Nov 2008

hi thanks for the info the truck electric point in front is 12v so no problems there.
we have a 85w and 80w 12v solar panels so parallel them and a stecca controller and run everything in the back on 12v.
will leave the other batteries in back as 24v seires and have a dropper for use as emergency power, found it was good to have a spare power source for when staying on a beach bush camping and the sun disapears for a few days.
cheers
dave