how do i hook up 2 12 volt batteries together and keep 12 volts?

Answer 1

Edwin is just using words he doesn't understand. Connecting two batteries the same size in parallel is fine. They'll charge and discharge pretty much equally. If one has a tiny bit more internal resistance than the other, it will just do a few percent less work than the other. Lead acid batteries are connected in parallel with no isolation all over the place in backup systems.

Answer 2

What happens if you hook two batteries (12 volt) on a back up sump pump.Will the charger,charge both batteries. 12volt system

Answer 3

Connect the positive of the 2 batteries together and then the negatives you will still have 12 volts. In other words connect the 2 batteries in parallel.

Answer 4

No, No, No! DO NOT CONNECT THEM IN PARRALEL!
This will not work for very long.

All batteries have and internal resistance and the chances of having two batteries that are perfectly matched are like a billion to one. Don’t do it. What will happen is that one battery will attempt to pass a charge into the other battery that has the mismatch and in time both batteries will be flat!

USE that Link kindly given by BOBWEB. These devices will allow the charge from your alternator to charge each battery as though they where independently connected, then when the vehicle is not running the device will isolate both batteries from each other whilst still allowing current to flow from both batteries thus doubling the current.

Answer 5

Battery isolators are so you don't waste both batteries using auxilary lights and still have power to start your engine. If you're not worried about this then batteries in parallel are fine.

Answer 6

Connect pos. to pos. and neg. to neg. That will give you 12 volts.

Answer 7

In parallel: (positive to positive and negitive to negitive)

Answer 8

Here's one way

http://www.ase-supply.com/category_s/20.htm?gclid=CL_s7-f70YoCFRtGgQodpx5cbg

Answer 9

parallel: (+ to +) and (- to -)