Batteries not holding 100% capacity...

[polocheck]

Came out this morning pack was at 50.5. Looks like converter is not the issue. Anything specific to look at with charger or any other component? Maybe several short drives and placing on charger will build it back up? JonnieB I know you mentioned in other posts how you were able to get old batteries back to 100% SOC. What were your procedures?

[JohnnieB]

Originally Posted by polocheck

Came out this morning pack was at 50.5. Looks like converter is not the issue. Anything specific to look at with charger or any other component? Maybe several short drives and placing on charger will build it back up? JonnieB I know you mentioned in other posts how you were able to get old batteries back to 100% SOC. What were your procedures?

I got them from 85% to 94% by charging the living daylights out of them for a month, then bought a charger that went into float charge after the regular charge cycle ended and they were taking 98% charge by the next spring and 100% that summer.

Basically, I'd initiate a charge cycle every morning after the cart had been put on charge the previous night. If I didn't drive the cart that day, I might initiate another charge cycle around midday, and another that night.

If I did drive the cart, it went on charge after each trip, no matter how short the trip had been.

FWIW: Never add anything except distilled water to your batteries, but if you read the instructions for the snake oil battery rejuvenation additives, they tell you to charge the batteries back-to-back like I did, which helps in some, but not all, cases. The subtle part is that the charging back-to-back does the magic, while the hyper-expensive snake oil just transfers money from your pocket into their pocket.

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A little clarification about batteries sitting in a partially discharged state.

The instant the charging current stops flowing through lead-acid batteries, they start self-discharging at about 1% SoC per day. It takes about half a day for the self-discharge to dissipate the surface charge cause by charging, so at 36 hours, the battery pack is at about 99% SoC, which is less than 100% SoC, so the batteries are partially discharged.

Whenever the batteries are partially discharged, there is Lead Sulfate on the plates. At first, the PbSO4 is in an amorphous state which can be changed back into Lead (negative plate), Lead Dioxide (positive plate) and Sulfuric Acid (electrolyte) by passing a charging current through the battery. As time passes, the PbSO4 crystallizes and Crystalline Lead Sulfate doesn't change back into the original chemistry nearly as easily. The more amorphous Lead Sulfate present on the plates, the faster it crystallizes and at about 70% SoC and below, it happens pretty quick and the battery ages (looses storage capacity) at a faster rate.

When you were restarting your PW-QE every week, your batteries were bouncing between 100% SoC and 93% SoC. I don't know when a PW-QE automatically restarts a charge, but if it is every 30 days, your batteries were fluctuating between 100% SoC and 70% SoC. That kept them out of the rapid plate sulfation range, but may be the reason, or at least a contributing factor, as to why they won't charge to 100% SoC.

Float charging keeps the battery at 100% SoC and prolongs their useful life.

When your PW-QE gives up the ghost, replace it with a DPI Accusense charger.

[polocheck]

Does anyone know if the QE charger kicks back on at a certain voltage or after a certain amount of time?

[PinballDad]

Originally Posted by polocheck

Does anyone know if the QE charger kicks back on at a certain voltage or after a certain amount of time?

I think someone told me once that it does not kick back on after battery drain. You have to unplug and plug it back in I think.

[rib33024]

A member posted a few days ago that it does turn back on when the volts get low, or after a certain time. But i have never seen one of these chargers do this, and it's the first time i have heard this

[JohnnieB]

Originally Posted by rib33024

A member posted a few days ago that it does turn back on when the volts get low, or after a certain time. But i have never seen one of these chargers do this, and it's the first time i have heard this

There is a statement alluding to that in the operator's manual for the 36V PW-QE (Model 915-3610), but I read posts here at BGW saying it does and others saying it doesn't.

The statement is in paragraph-5 of the attached page out of the manual. Sorry it is such a poor quality, but that's all I've been able to find on-line.

I don't know if the 48V version works the same as the 36V version.