wires to battery corroded through

well, these things are never simple or quick.

auto parts store had 10 gauge wire but not less, except for actual 4 gauge battery cables. but those had the wrong size stud rings. they had 3/8" 8 and 10 gauge stud rings which i bought.

i think the black/neg wire is 10 gauge so that's all good. but the red is bigger than that - guessing 8 ga?

went to the electric store. they have wire but don't think it will work. they looked at the cross-hatch of the wires showing several dozen strands and don't think what they sell is compatible.

if I buy 4 ga battery cables and clip them (kind of wasteful at $13 each) I would stil need a way to attach two different gauges together (4 ga red to 8 ga red and 4 ga black to 10 ga black).

Amazon. Make sure the wire is all copper. Typical auo stores have limited supply. Electric stores supply houses and buildings.

this probably seems simple to you, but a search for Rv 8 gauge wire at amazon rwsults in a huge variet of products.

https://www.amazon.com/s?k=rv+8+gauge+wire&crid=9YA463VKY7MI&sprefix=rv+8+gauge+wire%2Caps%2C165&ref=nb_sb_noss_2

Note if the connections to the battery are the standard crimp on ring connectors not a good fit.. You really need proper battery connectors.. The metal is a bit different... Different metals when you pass current especially around batteries. tend to corrode swiftly... Properly near identical metals.. Much much much more slowly.

rvshrinker wrote:

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3. How do I prevent this kind of corrosion in the future?

The BEST solution, is replace the wire, end-to-end, with marine grade, pre-tinned wire of the same size. If end-to-end replacement, cut the wire about 2' away from the the battery. Splice in the marine grade wire using an uninsulated splice and use marine/dual wall heat shrink tubing to cover it.

Gary45 wrote:
apply vaseline to bare connections, will prevent corrosion

Be GENEROUS !

rvshrinker wrote:


there's no way to tell how much life is left on these batteries, right? I'd hate to be somewhere and have them die on me. We don't live in a hot climate but the first few years I didn't care for them as well and they dried once and completely discharged once or twice.

Not so fast. There are many ways to tell how much life is left in your flooded cell deep cycle batteries.

1. At six years of age, you are on borrowed time.

2. The fact that you must add water monthly, and when charging, also means you are on borrowed time. Do you use distilled water?

3. The fact that they are off gassing (when charging) enough to damage the cables also tells you that you are on borrowed time.

4. Fully charge and equalize the batteries. Let them sit disconnected for several weeks. How well do they hold a charge?

5. Are the cases bulging at the exterior on the sides?

6. Does the specific gravity vary (as the batteries charge/discharge) relatively consistently, or, do one or more cells (usually the end cells) vary substantially from the others?

7. Does the fully charged voltage remain at/above about 12.8 volts for at least a day?

The above are all simple checks you can do today to decrease the chances that you are "surprised" on your next excursion.

Chum lee

Coupla wiring hintz. Make sure you are buying tinned copper wird--it does not corrode. Plain copper always will corrode. Do not buy " CCA" wire. That's cooper coated aluminum. Carries less power, corrodes, fools people who are just looking to save money.
Ask your library, or go to Amazon, for a book by Nigel Calder or Don Casey on BOAT electronics. They'll explain the best ways to select wire, properly buy and make fittings, corrosion proof your work.
It is easy to do it right. Will take twice as long and cost a bit more, but the work will hold up over time. The little details count.

CA Traveler wrote:

rvshrinker wrote:

3. How do I prevent this kind of corrosion in the future? Flooded batteries corrode. Try AGM, Li etc

Place a large GOB of Vaseline on top of the battery terminal/post and on any exposed copper. Make sure some goes underneath the terminal.

The corrosion is caused by gases escaping from around the the post. Vaseline "seals" it in !

There is a grease like substances used with Aluminum conductors, wire/busbar, to prevent corrosion.