One 6V battery discharging really fast

[RichieW13]

Almost 3 years ago I swapped out my 12V battery for two 6V (Trojan T-105) batteries.

Last weekend, I noticed that my trailer was losing power really fast after charging up. I used a volt meter and discovered that one battery was reading ~4 volts and the other was reading ~6 volts.

The water level looks to be fine on both.

Is it possible that one battery is just bad? Is there some other issue I should look for? Should I just replace the bad battery, or do I need to replace both to keep them approximately the same age?

[wopachop]

I guess he could grab his multimeter and some baking soda water.

Pop the caps and probe the battery acid. Dont forget to neutralize the battery acid on the probes with baking soda.

[BFL13]

RichieW13 wrote:
Almost 3 years ago I swapped out my 12V battery for two 6V (Trojan T-105) batteries.

Last weekend, I noticed that my trailer was losing power really fast after charging up. I used a volt meter and discovered that one battery was reading ~4 volts and the other was reading ~6 volts.

The water level looks to be fine on both.

Is it possible that one battery is just bad? Is there some other issue I should look for? Should I just replace the bad battery, or do I need to replace both to keep them approximately the same age?

No mention of an hydrometer!!!!

Absolutely must dip an hydrometer into all six cells to know what is really going on.

Say you are into the green on all three of one batt, but only on two in the other batt. Now you must decide whether to to get one new 6 or two new ones.

IMO it would depend on how many cycles the "good" battery has done and what its SG is on the three cells. If almost as good as new I would keep it and get one new one. Or if not, not.

[capacitor]

Ahh, my mistake! Sorry

[RichieW13]

capacitor wrote:
https://www.youtube.com/watch?v=9g1xLnFsob0Could be the way you put them in parallel.

I'm running the 2 x 6v setup, so mine are actually in series.

[capacitor]

https://www.youtube.com/watch?v=9g1xLnFsob0Could be the way you put them in parallel.

[Lwiddis]

X2, 2oldman. Replace both batteries.

[2oldman]

It's possible a bad connection can limit charging current to the one battery. 3 years is a year sooner than I went through Trojans, but maybe your usage is heavy. Replace both.

[Lwiddis]

Certainly! Correct voltage for bulk, absorption, float and equalization are important. Trojan has the numbers on their site. .

[RJsfishin]

OP
don't let them confuse you. You need a new battery. There aint no kind of equilizing (hi voltage) charging going to fix that battery w/ a stone dead cell.
Its just too bad you went w/ the hi $ Trojans, as you should replace w/ same.

[wopachop]

As mentioned above you might have lost a cell.

You can try what's called an "equalization charge" and see if the bad battery can still be used.

Wonder if the possible bad cell actually looks different if you shine a flashlight at night down the water holes.

[RichieW13]

wopachop wrote:
Know anyone who could bring over a charger capable of doing an 8v equalization charge?

Or if you have a 12v Battery Tender you can possibly use that on the single 6v.

Are you saying that the method of charging the battery can impact the length that the charge will last?

[time2roll]

I believe you have happened upon the very rare situation where your GC2 has a shorted cell.
Check your warranty but I think you need a replacement.

[wopachop]

Know anyone who could bring over a charger capable of doing an 8v equalization charge?

Or if you have a 12v Battery Tender you can possibly use that on the single 6v.

[madjack60]

Almost sounds like a cell in the battery is dying