Two Batteries (in series?)

Hi all. Any of you have experience hooking-up two batt's. for additional capacity? Winching,lighting, etc. ?

I want to do this for my CJ-5 snow plow rig. The elec. lift draws alot of amps. I used to know, but have forgotten how to connect the two batt's. correctly .

Will I need to make any other changes to the elec. system?

Thanks for any help!!!

 

series is going to make 24 volts... parallel should double the current. just take positive to positive and negative to negative

editing cause i missed the second part... i wouldn't think youd neeed to change the wiring (everythings goingto draw as much current as it wants and can't really be forced any). but there might be a problem with diodes or the like if something's trying to hold the current back. i'd lean towards no because it's just like jumping your car off, but you'd probably want some more opinionson that

 

Yes it wants to be parrallel or things will go pop I wouldn't think that you would need to do anything else, maybe a larger alt to keepthem both charged.

 

It's a good idea to connect the batteries to the charging system and loads through a battery isolator. This is just a heat sink with 2 high current diodes mounted on it to electrically separate the batteries (sometimes there is a protective box around the whole thing, and sometimes not). Split your aux. load from your starter circuit, and feed them from the separate batteries. With this setup, if your snow plow or winch kills one battery, you can still start your rig, and charge up the secondary battery at the same time the primary is charging. Connecting 2 batteries in parallel without any isolation just increases the total system capacity - at the same time increasing the load on the alternator, and your exposure to cell failure (one cell out of 12 goes down = system down).

 

If you're running something that really draws a lot of amps, make sure the wire is a big enough gauge to handle the amperage. Better to run in a wire that's TOO big than to fry your wiring.

 

Thanks much for the response guys!

MOJAVE, I'm not familiar with battery isolators. Is it a unit that is readily available and easily connected or a collection of parts with "some assy. required" ?

Jim

 

Another option is a boat battery switch. You can run one battery or the other or both or turn off them both. I have one in my boat that I can turn everything off and then pull the key. Good theft protection and helps eliminate any slow current draw.