Older AGM... balance?

I have a 2002 with some older Polaris (Deka) AGM batteries (6).

They were going pretty strong, then the motor when out in June… knew enough to keep the cart charged, but it sat all summer until I could replace the motor. (Blue D&D “11hp”), guy tested teh cells and said they were still fine, But now cart is “flat” (doesn’t have much acceleration, takes a while to get to speed, doesn’t get past 25 hardly at all (I reprogrammed the T2 and it would do 32mph on the stock motor (GPS) pretty easily back in June.

Trying to figure out how to get performance back to normal. Is the motor not at snappy at the OEM 5hp?

Are the batteries out of balance? (From getting tested maybe?) - Can I charge them with a regular car charger individually to help this? Do i have to disconnect them from the series wiring of the cart to do this? If not, do I throw the disconnect first?

Anything else i should try? - Batteries are an imminent but hoping to drag that one out a little longer until i can afford some SDI’s and a BMS

Yes you can charge them one at a time with a battery charger appropriate for agm

if the car sat for some time, check to be sure the rear brakes are not dragging from stuck cables.

Does anyone know how long it takes for motor brushes to wear into the commutator? I could see a lack of power from brushes with small points of contact with the commutator if they are not worn into the curvature of the commutator.

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Have you checked for dragging brakes ?

AGM are just spill proof lead acid. They are subject to all the same sulfidation as a flooded battery. If they are damaged voltage can fall rapidly after being driven as little as a mile. You may also have one dead one and 5 decent, but that one will drag the whole cart down.

D&D makes both “speed” and “torque” motors. I’m not sure what the internal differences are but the torque motor wont spin at the high rpms.

If you have the speed motor, then the T2 parameters from the short GE5 should be fine to start with and performance should be decent. Iirc, all R$F changed on my controler when i bought a motor from them (rebranded d&d) was they lowered the field weakening and raised the max overspeed (top speed).

The first and most obvious that has not been mentioned yet- Is the speed selection in Turf mode?

Rather than guessing at what is wrong, you should get out a meter and start checking the batteries.

Check and note the V of each one. If they are not within 0.1v of each other do a balance. Check your top V to make sure your charger is on the correct profile.

No- You don’t need to disconnect them to put a car charger on the low ones to bring them up to balance.
Did your guy Do a Load test? Try putting your meter on the controller POS and NEG directly and check Full Charge, then take it for a run or do a Brake Stand Test and see how far it drops under load.

The above suggestions to check for dragging brakes and even for proper inflated tires is a good one.

But usually the Blue motor should perform better than the old GE Short. Depending on where this motor came from maybe it might have a new set of brushes that have not set to the comms and in need of breaking in. I call that extremely lazy and should have been at least rough cut.

Where did the new motor come from?
Is this motor new or rebuilt?
Since this motor is installed and you ran it, Is it running smooth and not making any unusual noises? (just low on power)?

It might be worth pulling this motor out again for inspection or at least pulling the band cover off the end to get a look at the brushes.

I still remember the guy that posted here a while back that just had his motor serviced and it was returned/installed with the brush springs still in the service position. They weren’t pressing on the brushes at all. It is something that is easy to miss and we all get in a hurry in this world of distractions. All it takes is one brush not making contact and you are only working on half a motor.

So much good information here. Thanks @AssyRequired. I’ll have to start going through your list Don’t own a meter, but it’s probably about time… Car rolls freely, i don’t think anything is dragging. Just feels sluggish. Charger shows red flash if i unplug and recharge a couple of times in a row (I think that means voltage high) so it’s hard to think it’s not getting a full charge (And shows 100%… although that drops relatively quickly driving it compared to what it used to. No funny noises really. What would springs in the service position look like?

How did you “keep the cart charged”? Leave it plugged in or cycled AC power on the charger every couple of weeks?

Both kind of. I have it plugged in to a smart plug that cycles the power every so often (Once every couple of days if I remember correct.

On more than one occasion my old 02 would still roll somewhat easily with a push, but once the vehice was up in the air i would find that one or two of the bare assemblies was dragging ever so slightly, which was just enough to affect accrleration and take 5 miles off the range.

You really need to jack the cart up to where you csn spin the tire & wheel(s) by hand to rule out dragging brakers etc. Check both front and back. When you spin the fronts, try them free, and then again after blocking the opposite side.

Another thing that i ran into was that the blie motor i recieved the end of the collet was protudung too far. With my motor it was pretty extreme, the female collet was bottoming out on the differential and i couldnt get the casings to contact for the bolts. Had to grind & flap sand it down. Now, if it were just a slight contact, then you would just see some extra drag until the end nlbearing went out from the side loading.

Thanks, i’ll jack it up and see.

ok, that’s better than leaving it plugged in and thinking it’ll start recharging when the battery voltage dips. But probably a bit to aggressive on the cycle period because it might end up putting too many top-charges on them. A better cycle period would have been around 2-3 weeks.

Time to try some of the battery-condition tests @AssyRequired listed.