Middle batteries in pack low.

[Engine17]

I have a 01 club car ds 48v. USbatteries installed one 10/15. The two middle batteries in my pack got dry and are reading low. Cart won’t run well under a load. I know it’s best to replace all the batteries at once, but my current financial situation doesn’t allow that. My options are to buy two new ones or let the cart sit.
I have tested all the batteries with a multimeter at rest and riding up a big hill.
Curious if you all think I would be crazy to just replace a couple of batteries.
I took three reading. 1 idle at bottom of hill. 2. Lowest reading under load 3. Stabilized Reading half way up hill. All reading were taken consecutively so it’s possible the batteries were losing charge with every trip.
Sorry fo the long post thanks in advance for the help.

Starting on Drivers side
1. 2. 3
Battery 1 8.53. 7.3. 7.65
Battery 2. 8.53. 7.3. 7.6
Battery 3 8.34. 7.01. 7.4
Battery 4 8.40. 7.0. 7.42
Battery 5 8.47. 7.2. 7.6
Battery 6 8.50 7.2. 7.63

I tested them today at rest at full charge and reading were as followed. This is 3 charges after load test.
1. 8.64
2. 8.64
3. 8.43
4. 8.47
5. 8.54
6. 8.60

[yawood]

Those readings aren't too bad, especially if they were taken after resting for 12 hours or more. Yes the centre batteries are a little weaker but you should get by with a bit more use yet.

Have you tried reconnecting the charger immediately after a full charge? This is the method for producing a balanced charge. The other thing that could help is to use a float charger like the "Save-a-battery" after a full charge with the CC charger.

As the batteries are 4 years old you can expect some drop in performance but you shouldn't have to change them yet. Only you can really tell if your terrain is hilly enough to give you a problem.

I would continue with a good charging routine and checks on water and those batteries will become better after more charging. That said, they will probably never get to the level of the others but will come close.

[Engine17]

I have not tried charging immediately after a full charge, I will do that. I have been charging it immediately after short rides.
I use this cart as a hunting cart. There are to long hills on the property the first one is 2 minutes into the ride and the second is 5 minutes. The dash meter shows the voltage dropping close to 43 on the first hill and below 43 on the second with only 2 people on the cart. I have to baby the gas pedal to get up the second without dropping the voltage below 43.
Do you think replacing those two batteries would help with this? I’m afraid the two lower batteries are going to cause problems with the others.
Thanks

[Fairtax4me]

43V under load is not bad but it's not good either.

If you still have the original powerdrive charger, let the cart charge to full, then unplug the charger, wait about 15-20 seconds and plug it back in. This should start a maintenance charge cycle which will help equalize the batteries. US batteries are good quality and will be able to take a bit of a beating, but as they age batteries will have sulfate buildup on the plates. An equalization charge will help reduce the sulfate buildup and can help bring the voltage of all of them up.
I would not replace the pack unless you get to the point that it will not make the trip around your property.

Check the air pressure in your tires, because any extra drag from low air pressure will certainly not help when climbing a hill.

[alangsam]

Hold out a little longer and then go lithium.

[Engine17]

Before those two batteries went dry, I could climb the first hill without dropping below 46. I really like the idea of lithium batteries but haven’t reasearched it much yet. That was part of my thinking of just replacing those two to buy another yr or so. I can barely make it up the second hill now where before it wasn’t a problem.
I will try the maintenance charge and see what it does. Thanks

[jjjtadpole02]

Do you have lights on your cart? Many people have lights wired to 16V power (using battery 3 & 4) instead of installing a 48/16V reducer. If that is your case, then that is the root cause of the lower voltage on those. You could get away with replacing the two middle batteries and replace the others as soon as financially possible.
Chargers cannot add power to individual batteries and therefore the the power draw from your lights is not being fully replenished.

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[Engine17]

No lights or any electrical accessories.

[Engine17]

Okay I have done a full charge followed by a maintenance charge. I won’t have a chance to drive the cart for a couple more days. Would it be beneficial to unplug the charger for a minute and do a second maintenance charge? Thanks

[jjjtadpole02]

You can try it but it sounds like you've reached the life of those batteries based upon the age.

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