Adding a second battery to a car how to?

Question

Im looking at adding a second battery due to 2 amps and extra equipment now my battery is in the trunk would i wire the second battery in paralell pos to pos and neg to neg to increase the amps or in series without frying my electrical system

Answer 1

The batteries should be parallel and there should also be an isolator to keep the second battery from draining the primary one. I hope your alternator can keep up with them.

Answer 2

Yes, the batteries should be wired in parallel. Wiring them in series increases the voltage. You don't want that.



Keep in mind that adding a battery increases the load on the alternator. Make sure that your alternator is up to the task of keeping both batteries charged.

Answer 3

Stinger 80 Amp Battery Relay Isolator installed easily, and works great. Makes a rather loud "thump" when it energizes, but that is to be expected from an 80 amp relay mounted on the firewall.



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