P1000 Secondary Battery Static Voltage

[packer58]

For those of you guys / gals that have the duel battery with isolator setup in your P-1000, what is the static resting voltage of your auxiliary battery. I have installed a second battery with TrueAm isolator along with other accessories. My resting voltage on the second battery is 12.4+/-.
Seems a bit low .... What do you guys think ??

 

[Admin]

 

[NewHere2]

Yep, a little low. Typically I see 12.7 or 12.8 at rest. Most likely due to the quality or age of the battery.

Hope @bumperm drops in. He is knowledgeable. Trust what he says.

 

[bumperm]

12.4 volts at rest is about 65% charge on a healthy lead acid battery. Is there any load on this battery? How is the sxs used? Does it run long and often enough for the on-board charging system to charge the batteries? Is there any parasitic load on this battery? Try charging the battery in question with a trickle charger or smart charger at least overnight. After you remove the charger, let the battery rest for at least half an hour and check the voltage again.

 

[Mark in Northern Iowa]

👆👆👆👆Nice chart. 👍
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Engine running

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Engine off

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Have a good day

 

[packer58]

12.4 volts at rest is about 65% charge on a healthy lead acid battery. Is there any load on this battery? How is the sxs used? Does it run long and often enough for the on-board charging system to charge the batteries? Is there any parasitic load on this battery? Try charging the battery in question with a trickle charger or smart charger at least overnight. After you remove the charger, let the battery rest for at least half an hour and check the voltage again.

View attachment 398062

Machine doesn't get used a ton this time of year, i'll put it on the charger (2 amp) for the rest of the day and go from there. A little back story ....... I store my machine in an enclosed trailer, a week ago i pulled it out to do something and noticed my aux battery was way low (4.5 v) Then noticed that i had left my aux / off / key on switch in the aux position and my dome light switch was on. Not sure if that deep discharge on the aux battery has affected it somehow. I have since put it on the charger but possibly not long enough.

So, let me get these batteries on the charger and we'll go from there,

Thanks

 

[Scoop]

Yes, deep discharging and not recharging will damage your battery.

 

[bumperm]

The aux battery is likely sulphated due to the deep discharge and being left in that condition for some time. That's death on lead-acids and it will not recover it's former capacity. Probably time for a new one, especially if it's several years old (though if treated well, and stored in a charged condition, the battery should last 5 or more years). Batteries in storage should be charged every few months. Colder storage temperatures are better than hot. When below freezing, the battery needs to be fully charged to survive, as a discharged battery, or very cold temperatures, can freeze and crack it open.

 

[packer58]

The aux battery is likely sulphated due to the deep discharge and being left in that condition for some time. That's death on lead-acids and it will not recover it's former capacity. Probably time for a new one, especially if it's several years old (though if treated well, and stored in a charged condition, the battery should last 5 or more years). Batteries in storage should be charged every few months. Colder storage temperatures are better than hot. When below freezing, the battery needs to be fully charged to survive, as a discharged battery, or very cold temperatures, can freeze and crack it open.

Approx 25 days when i noticed the deep discharge ..... @bumperm

 

[packer58]

Ok fellas, just following up with this. Charged batteries on 6 amp setting for 24 hours and 4 days later the voltmeter reading is 12.5 / 12.6. I'm now fully convinced i left my dome light on and drained my second battery

 

[Bama-Daniel]

12.4 volts at rest is about 65% charge on a healthy lead acid battery. Is there any load on this battery? How is the sxs used? Does it run long and often enough for the on-board charging system to charge the batteries? Is there any parasitic load on this battery? Try charging the battery in question with a trickle charger or smart charger at least overnight. After you remove the charger, let the battery rest for at least half an hour and check the voltage again.

View attachment 398062

@bumperm - Not having problems now but what voltage would be recommended to replace?

 

[bumperm]

@bumperm - Not having problems now but what voltage would be recommended to replace?

It's not so much about "at rest voltage" as it is about battery capacity. A new lead acid battery starts out life with a given capacity, during the first few charge/discharge cycles (assuming it's not discharged more that 50% - which is bad) it will gain some capacity . . . then it's all downhill from there!! A well cared for battery will still loose capacity over time, and abused battery, much quicker. Left discharge is like poison, as is running it into the ground. Storing or using it in high heat environments (I'm thinking under the seat here) will also reduce it's expected life span. A lead acid battery, at or near the end of it's useful life, can have a decent looking voltage after being charged - - it's called a "surface charge". Such a battery can display a good voltage with almost no capacity.

So perhaps the best practical way to test the battery is with a cheap (Harbor Freight) load tester. You can also do that with a voltmeter and a load, comparing how quickly the voltage drop occurs between the battery under test and a known good battery.