36v Ez go txt pds 6 mo old batteries dying rather quickly

[Valtamirano]

Ok guys I’m having a little bit of an issue. I have a 2002 36v ez go txt pds with batteries about 6-8 months old. I can go about 30 min non stop average speed on flat surface and my cart starts to go really slow and stops. I wait a few minutes it goes a minute or two then stops. I got it home after all this and checked the batteries and they were all reading between on an average 5.8 -5.9 volts . I tested the batteries on a load and got a drop to about 5.4-5.6. I can’t figure out how hat the issue is. I maintain monthly I have new cables the voltage right now is 34v to the controller and it’s apparently dead or going slow.


I have tried the solenoid which I should. The battery charger is auto on/off but not sure the brand.

We use our cart almost daily. And I live in Texas so not to cold.

Thanks for the help everyone

[Doubles Shooter]

34 volts is a very dead battery. You should have 38.2 on a full charge after a 12 hour rest. Can you post a picture of your charger? What brand and size are your batteries?

[Valtamirano]

I haven’t charged yet, but I will check at full charge. the amount is the 34.5 was under load load tested as well not charged. Just confused as to how the single battery shows good but full set is bad? Charger is old, it may be that as well please see picture. Just want to make sure it’s the charger by before I buy a new one. If I do buy a new one which on should I get at a decent price?

[JohnnieB]

The batteries ought to be charged after each use, or at least overnight after each day the cart was used.

Cart batteries should not be used when SoC (State of Charge) is 50% or less, which is typically a bit above the nominal voltage rating. In other words, a 6V battery whose At-Rest voltage measures 6.00V or less should not be used until it has be recharged.

Granted, irreversible physical damage to the plates doesn't usually start occurring until 1.5VPC (Volts per Cell) is reached, which is 4.5V for a 6V battery, but the battery's usable lifespan is significantly shortened by doing so.

In other words, if your six month old batteries aren't kept charged and are often used when below 50% SoC, the may already be at their end of life.

[Valtamirano]

I charge the batteries as noted in prior post. Since we use it daily never let them die down either. And maintain monthly as required. Thanks for the help

[JohnnieB]

Put batteries on overnight charge and measure the battery pack voltage with a handheld DVM in the next morning before cart is moved.

If the voltage reading is less than about 38.2V, then there is either a battery pack or charger issue, maybe both.

What make/model are the batteries? 100% SoC voltage varies with brand.

If they are US Battery brand, your PW-II charger is likely not to be fully charging them. (38.5V is 100% SoC for USB brand batteries.)

When charger is first connected does the ammeter show about 20A?

[Valtamirano]

Amp charging is not showing 20 A, which I thought was off. The voltage on the battery at full charge is above 38v. Still leaning to charger no giving enough amperage to batteries

[JohnnieB]

Originally Posted by Valtamirano

1. Amp charging is not showing 20 A, which I thought was off.
2. The voltage on the battery at full charge is above 38v.
3. Still leaning to charger no giving enough amperage to batteries

1. Specifically, what is the max amps the ammeters show when it is first plugged in?

2. How long after battery charger shuts off does the battery pack read "Above 38V"? Hopefully it was 8 hours or more, otherwise the reading is erroneously high.
Note: For battery pack readings the voltage needs to be resolved to at least 1/10th volt. For individual batteries, 1/100th volt resolution is needed.

3. Those are decent batteries and the PW-II should charge them, but it might be time for a more modern charger.

Here is a service manual for a Lester-II, which is the same as a PW-II except for the labeling.