Total Charge III Problem

[GThompson]

Originally Posted by JohnnieB

Reconnect charger and measure the battery pack voltage while on charge. If the charger stays on until the on-charge voltage climbs to about 45VDC, the ammeter may be all that is needed.

Thanks JohnnieB, Voltage did go up to about 45 volts then cut off. So will order an ammeter to replace old one and test charging after batteries have gone down some.

[EEBadHabit]

Going to resurface this thread as it is one of the better ones about the Total Charge III I have found.

My batteries have been charging up on the charger, but when I now run the cart I only get about 10 min until they dropping to about 30V under load and just over 36V no load. Water level is good. I put my GoPro on the volt meter while charging and recorded 42.7 when the Total Charge III turned off. I did just replace the board in the charger. The board I purchase was on Amazon and said by EZGO manufactured by GolfRama.

I downloaded the spec from above and didn't see the 45V requirement you mentioned JohnnieB. Is there some circumstance where the charger would on-purpose shut off before 45V or is there some issue with the control board?

Thank you JohnnieB for the help you have provided in this thread.

[JohnnieB]

Originally Posted by EEBadHabit

Going to resurface this thread as it is one of the better ones about the Total Charge III I have found.

My batteries have been charging up on the charger, but when I now run the cart I only get about 10 min until they dropping to about 30V under load and just over 36V no load. Water level is good. I put my GoPro on the volt meter while charging and recorded 42.7 when the Total Charge III turned off. I did just replace the board in the charger. The board I purchase was on Amazon and said by EZGO manufactured by GolfRama.

I downloaded the spec from above and didn't see the 45V requirement you mentioned JohnnieB. Is there some circumstance where the charger would on-purpose shut off before 45V or is there some issue with the control board?

Thank you JohnnieB for the help you have provided in this thread.

Technically a lead-acid battery is not fully charged until the SG (Specific Gravity) of the electrolyte ceases to increase while there is a charging current passing through it. The voltage on the battery's terminals track the SG of the electrolyte, so it can be inferred that the battery isn't fully charged until the on-charge voltage ceases to climb and modern lead-acid battery chargers use a dV/dT (change in voltage over change in Time) process to terminate the charge cycle when the battery is fully charged. During the era of the ferroresonant transformer type chargers (Such as the TC-III) the circuitry needed for dV/dT was too bulky or too expensive, or too unreliable to be installed in consumer grade golf cart chargers, so some committee somewhere can up with a voltage to shut-off the chargers at that was high enough to "adequately" charge new batteries, yet low enough not to severely damage old batteries. The magic number was 45V and some tolerance was added due to the accuracy of the voltage compairitors at the time. So the end results was 45V +/- 1V or a range from 44V to 46V.


For the TC-III to turn of either the on-charge voltage (as measured at the control board) has to climb into the 44V to 46V range, or the batteries have been on charge for over 12 hours (16 hours for some versions of the control boards)

If there is excessive resistance in the charging circuit, it is possible for the on-charge voltage as seen by the control board to be higher than the on-charge voltage at the battery pack's main + and - terminals. In other words the control board may have seen 44V or above when the battery pack was only at 42.7V.


--------------
What make/model batteries?
How old are they?
What is the at-rest voltage 12 hours after charger shuts off?

[EEBadHabit]

What make/model batteries?
Costco Interstate #850284

How old are they?
Date codes 5/17 & 7/17

What is the at-rest voltage 12 hours after charger shuts off?
37.1V

So sounding like these low cost batteries may have had their life?

I have kept the electrolyte level as it should be. Part of the issue may be that I use it to tow a jetski around the yard and a couple times have run it out of juice doing this which I didn't know at the time is not healthy for the batteries.

Thanks for the feedback.

[JohnnieB]

Originally Posted by EEBadHabit

1. What make/model batteries?
Costco Interstate #850284

2. How old are they?
Date codes 5/17 & 7/17

3. What is the at-rest voltage 12 hours after charger shuts off?
37.1V

4. So sounding like these low cost batteries may have had their life?

5. I have kept the electrolyte level as it should be. Part of the issue may be that I use it to tow a jetski around the yard and a couple times have run it out of juice doing this which I didn't know at the time is not healthy for the batteries.

Thanks for the feedback.

1. 6V-210AH economy grade. Less run-time on single charge and shorter cradle to grave lifespan than standard grade batteries. Cost effectiveness depends on cart, how it is used, how often it is used and owner's performance expectations.

2. A little over 2 years.

3. Only charging to 70% SoC.

4. Try some back-to-back charging and they might recover some.

5. Keep batteries as fully charged as possible and practical and they'll last longer.