Disconnecting Series/Parallel Batteries

It’s all about the sequence…

Mike,

Thanks for sharing about disconnecting batteries, but I have a question about what process would you recommend for those of us who have 4 batteries hooked together in series/parallel?  Which battery do I disconnect first?  Blessings! - Mark Robbins

Hey Mark,

Here’s the configuration you’re asking about. This is the proper way to connect four 6-volt batteries together to double the battery voltage and amp-hours at the same time.

The Sequence

The first thing to disconnect is the battery terminal tied to RV chassis ground. In this diagram it would be the lower-left battery terminal. Doing this terminal first is the safest procedure since once disconnected there won’t be a short circuit if your wrench accidentally makes contact with the metal chassis.

Once the battery negative chassis wire is removed it’s safe to disconnect the rest of the terminals in any order you like, as long as you don’t accidentally let your wrench make contact between the batteries themselves.

Then when installing batteries you should reverse the process and save making the negative grounded terminal connection for last.

Use an insulated wrench if possible

Plus I think the safest way to disconnect batteries is with an insulated wrench. While you can spend hundreds of dollars on one from SnapOn, Harbor Freight has an affordable 1/4” or 3/8”drive insulated ratchet wrench that works well and keeps you safe from shorting out a battery (with dire consequences).

Let’s play safe out there… Mike