Battery Adventures; Battery Wet on top, overcharging?

[jross20]

Anyone have issues with their battery getting "wet" on top? I've got an X2 glassmat battery that's been good to me for a while...but I keep noticing that it has "tiny puddles/moisture" on top. Not a lot but it bothers me.

So I'm wondering if the truck isn't regulating the charge voltage or something? I feel like I recall learning that all vehicles had a charge shutoff at a specific voltage. That's about where my old knowledge of that stuff ends so I need a refresher...
Is that the regulator?

What's the correct procedure and voltage ranges I should look for on our trucks? Right now in the garage, around 35-40° F, she reads 12.9 volts. I'm about to check it after running for a while.

Edit, she reads 14.32 volts after a cold start. Going to go drive now

Edit, well now after driving she says 12.9 volts again. That seems perfect I guess?

 

[jgue467]

Over/under charging leads to the 'crust' buildup on the terminals.

12.9 before a start and 14+ after sounds good to me.

The moisture maybe acid coming out from a loose cap and all the movement of driving.

 

[alumarine]

Is that last reading of 12.9 volts at idle or with the motor off?
If at idle, it's too low.

 

[phattyduck]

Is that last reading of 12.9 volts at idle or with the motor off?
If at idle, it's too low.

And if its off, it better be right after turning off. Otherwise its too high...

-Charlie

 

[Romeo1]

Batteries do go bad. Even good ones. Clean cables, posts and alternator output are a big deal. Dirty grounds cause all kids of issues. Cables can even be corroded internally. Most systems are internally regulated anymore, and some have and exciter wire, some don’t.

Keep battery tops clean. Surface discharge can occurs when dirty and potential is available.

13.4-13.9V is solid and working well. Begin switching on various electric loads and see what happens while running.

Battery voltage at rest is dependent on fitness and temperature. A load test will verify battery health. Never assume battery health. Age doesn’t mean jack. My battery pass/fail is load to 1/2 of rated Cold Crank Amps for 10 seconds.

 

[19963.4lsr5]

Those AGM batteries are sealed. If they need to vet it will be through one of the posts.

Your charging voltage is normal. The voltage regulator is temperature compensated. As in the hotter the voltage regulator gets the lower the charge voltage will be. Your rig running without any accessories on draws around 12-13a and the Alt will push around 2a to the battery if it’s fully charged.


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[jross20]

Over/under charging leads to the 'crust' buildup on the terminals.

12.9 before a start and 14+ after sounds good to me.

The moisture maybe acid coming out from a loose cap and all the movement of driving.

Well there is no crust thankfully, just moisture

Is that last reading of 12.9 volts at idle or with the motor off?
If at idle, it's too low.

That was right after I shut her off. Say within 45-60 seconds of shutting off.

Batteries do go bad. Even good ones. Clean cables, posts and alternator output are a big deal. Dirty grounds cause all kids of issues. Cables can even be corroded internally. Most systems are internally regulated anymore, and some have and exciter wire, some don’t.

Keep battery tops clean. Surface discharge can occurs when dirty and potential is available.

13.4-13.9V is solid and working well. Begin switching on various electric loads and see what happens while running.

Battery voltage at rest is dependent on fitness and temperature. A load test will verify battery health. Never assume battery health. Age doesn’t mean jack. My battery pass/fail is load to 1/2 of rated Cold Crank Amps for 10 seconds.

Hm, okay I'll give those ideas a try and test some more!

 

[19963.4lsr5]

And if its off, it better be right after turning off. Otherwise its too high...

-Charlie

AGM and some high output lead acid batteries that are doped with calcium will have a resting voltage a little higher than the normal 12.7v we are use too.

At key off my interstate sits at 13.1 for awhile.


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[jross20]

So to conclude, I did a lot more testing as mentioned above and things do seem to all be in the normal ranges. So, I'll clean of the battery and see if it returns. So far the battery has been great in terms of lifespan. Approaching 2.5 years without a hint of "slowing down".

I guess time will tell.
:blabla: