Marathon started struggling to go up a grade

[rib33024]

44V measured with the charger still attached and reading at the battery terminal?

Yes this would be with the charger on and hooked to the batteries. The charger should take the battery pack up to around 46 volts before it turns off

[Timberwolflt]

It doesn’t hurt to know what the pack voltage is at just before the charger shuts off... then again after the 12 hour rest

I suspect you’ve identified your issue... the digital meters are much more accurate but even those ain’t perfect... I have 2 digital meters and a multimeter and I get 3 different readings... They’re each .3V apart but still way better than a bar meter

[baymee]

Yesterday at noon the battery voltage moved up to 38.9 from 36.3, 20 hours earlier. Today after another 28 hours of charging, the voltage is up to 40.3. So, it's going to be slow go.

I don't trust the male and female plug connection. It is very sensitive to movement and has to be plugged in just right. so that may be a necessary change in addition to the voltage meter.

[cgtech]

Originally Posted by baymee

Yesterday at noon the battery voltage moved up to 38.9 from 36.3, 20 hours earlier. Today after another 28 hours of charging, the voltage is up to 40.3. So, it's going to be slow go.

I don't trust the male and female plug connection. It is very sensitive to movement and has to be plugged in just right. so that may be a necessary change in addition to the voltage meter.

Good point, if the charger handle has to be plugged in "just right", thats a sure sign of problems at that point. But, if 28 hours of charging only increased voltage by 1.4v, I think theres a charger problem too. (Like a bad capacitor). Was the charger actually on & charging that whole 28 hours? (Or just plugged in for 28 hours).

[meimk]

Originally Posted by cgtech

Good point, if the charger handle has to be plugged in "just right", thats a sure sign of problems at that point. But, if 28 hours of charging only increased voltage by 1.4v, I think theres a charger problem too. (Like a bad capacitor). Was the charger actually on & charging that whole 28 hours? (Or just plugged in for 28 hours).

I also have to ask - what charger do you have? If it's one of those ebay cheapo's that only runs 5 amps that would explain the slow charging and extremely long charging times.

[baymee]

The bar graph volt meter is a Curtis brand. The charger is an EZGO _ _ Xtron total charge III with an output of 36V at 21A DC. The voltage is now up to 41.3 after another 18 hours. I should have a nice electric bill this month.

How hard to diagnose a bad cap?

[baymee]

I found some info from JohnnieB that I'll look over this evening. I noticed my charger gauge is showing the needle on the far left, maybe 1 amp dc charging.

[Timberwolflt]

You definitely have a charger issue..

Your TV is drawing more kwhrs than that charger is at that rate... nothing to worry about

[baymee]

Sometime in the last 30 hours, the charger shut off. The voltage now is 38.1. So, I plugged it in again and will see what it is tomorrow. It was 41.3, 30 hours ago, but moving up slowly.

[meimk]

38.2 is considered 100% - measured 12 or so hours after the charger has shut off. That time allows the batteries to settle, so you are reading the actual state of the batteries instead of the residual effects of the charger. The end stage of the normal charging process is higher voltage at lower amperage, so it does need to settle before you can get an accurate reading.