Battery question (non-power tool)

[Dan Bundy]

The battery in question is a 12 volt, 31 ah wheelchair batter, though I'm using it in a remote controlled golf caddy. Recently replaced the battery. the old one was starting to just make it through 9 holes and was around seven years old.

Took the new one home last Saturday and put it on the charger and charger showed all the correct lights to indicate charging/charged. Monday a.m. took it off the charger because I was playing after work. When I get it all loaded up and hit the "go" button, it was very sluggish. I had to give it some assistance, particularly up hills. Finished the 9 holes, took it home, back on the charger. Tuesday afternoon I took it off the charger and tested it with multimeter - 12+ volts. Ran it around the yard unloaded, then loaded (very sluggish) for 5-10 minutes and checked it again and it showed 10.X volts. Today (Wednesday) I took it off the charger before work to simulate a golf day and tested it when I got home - 12.9 volts. Ran it some more unloaded (again sluggish) - maybe 5-6 minutes - then tested it again and it was 12.5 volts.

Does the power come from the volts? That's my assumption. Can it test to 12 volts but still not be "full strength"? Leaving the battery off a charger while at work had never been an issue, including with the recent old battery - it started off strong but ran "out of gas" toward the end of the round - so that shouldn't be the issue.

Is there anything I can do to further test things (with the caveat that I'm not particularly electronically inclined)?

I am in contact with the maker of the caddy (Kangaroo Golf), but I was hoping to eliminate the battery as a problem, if possible.

Thanks.

[Maurice Mcmurry]

Voltage drop under load is how the tester at the auto parts store works. You could try having it tested at an auto parts store. Also check for a date code. I bought a "new" battery that turned out to all ready be 3 years old. Getting frozen when low on charge is hard on batteries too.

[Paul F Franklin]

Is the battery the same type and size as the original?

Correct voltage is important, but voltage alone tells you little about how much energy the battery holds or how much power it can deliver. Power is volts multiplied by amps (current) and it is the current flow that is really doing the work. Measure the voltage at the battery when the cart is operating under load. You may find the voltage is dropping well below 12 volts under load because the battery cannot deliver the current the cart is trying to draw from the battery.

If the voltage is dropping a lot under load, it may be a bad battery, or it may be that the cart is drawing more current than it should because of some problem with the cart, such as lack of lubrication. There's no easy way to tell where the problem is without knowing how much current the cart should draw under load and measuring what it is actually drawing.

[Warren Lake]

just went through this with the Saturn. Supplier name brand told me three times and showed me volt meter it was fine, even gave me a print out, I said do you have a Loadmeter. He said yeah and brought out a really pro model. In seconds it dropped and sailed past the lowest of 9.6 which is where fail comes in. Lucky my past mechanic had shown me his more simple meter and said to replace it.
.
Meter they had was a Quick Charge made in USA C1600 Plus 6, 8, 12 volt battery load tester. Left with a new battery no charge.

[Dan Bundy]

Yes, battery is same make, model, etc. (Duracell 12v, 31ah gel battery). Part of the date sticker is missing (last number of the year) so it's possible the battery is from as far back as 2020.

I forgot to mention in the summary/questions above that when I lift the drive wheels off the ground, they speed up. I'm not sure how to test it under a "working" load, though I can test it while the wheels are off the ground and the motor is running. My multimeter only has probes, not clamps -- maybe tape the probes to the terminals somehow?

Thanks for the input.

[Bill George]

You can purchase simple insulated jumper clips and use those to clip to your meter leads and then to battery terminals. With the date code missing I would guess your new battery is old! Gel cell batteries require a special charger... is your charger rated for it or just plain lead acid batteries? Hmm new ones come with a Lithium battery.

[Dan Bundy]

UPDATE:

Managed to figure out a way to attach the multimeter to the battery. Battery was showing around 13v fresh off the charger. Stayed around 12 going downhill on the driveway, dropped to around 10 coming up (not sure of the pitch but it's not terribly steep, though it is noticeable). Drove it into the grass, which was also uphill, though not as steep as the driveway (barely noticeable) and the meter dropped to low 9v and even down to 8v a couple of times. Once back on the driveway it came back up to around 9v maybe 10v. I parked it and put the battery back on the charger.

Bill, the battery is the same make and model (Duracell 12v 31ah gel battery) that I am replacing the charger is one that I got when I got the previous battery (the one getting replaced) and it has been fine for however long I've been using it. Lights indicating charging, etc., appear to work properly.

[Warren Lake]

on a car you can put your headlights on for some amount of time, simple test and I dont remember the time.

If you want to do it better you have a load thing like my mechanic had or better still the battery place as that was was the Martin of those meters. Had my mechanic not come over with is load thing and taught me then I would have left the battery place after being told three times it was fine, them showing and proving that it was fine. What is that? top company. Good one kid listened to me and was up to going out back and bringing the load thing. Good I didnt back down but would have had the mechanic not come over and educated me.

He also had little clamp on meters that would telly amps when you started the car and what the starter motor drew.

[Bill Howatt]

Batteries are always a chemical mystery! I'd say you did a load test and the battery didn't pass the test. IMO, 13V fresh off the charger indicates it was reasonably charged and shouldn't have dropped like it did unless there is some problem with the motor/drive. Battery would be my first guess.

[Jim Koepke]

Is the battery the same type and size as the original?

Correct voltage is important, but voltage alone tells you little about how much energy the battery holds or how much power it can deliver. Power is volts multiplied by amps (current) and it is the current flow that is really doing the work. Measure the voltage at the battery when the cart is operating under load. You may find the voltage is dropping well below 12 volts under load because the battery cannot deliver the current the cart is trying to draw from the battery.

If the voltage is dropping a lot under load, it may be a bad battery, or it may be that the cart is drawing more current than it should because of some problem with the cart, such as lack of lubrication. There's no easy way to tell where the problem is without knowing how much current the cart should draw under load and measuring what it is actually drawing.


just went through this with the Saturn. Supplier name brand told me three times and showed me volt meter it was fine, even gave me a print out, I said do you have a Loadmeter. He said yeah and brought out a really pro model. In seconds it dropped and sailed past the lowest of 9.6 which is where fail comes in. Lucky my past mechanic had shown me his more simple meter and said to replace it.
.
Meter they had was a Quick Charge made in USA C1600 Plus 6, 8, 12 volt battery load tester. Left with a new battery no charge.

Paul & Warren say about all there is to say.

Either the battery is defective or your caddy motor has a problem and is drawing more current than the battery can supply. Many auto parts stores have a load meter. If you battery wasn't purchased through the mail, the place where you bought it should also have one.

jtk

[Paul F Franklin]

Dan,

Try the same test with the old battery, freshly charged, if you still have it. It's normal for the battery voltage to drop under load, but I think yours is dropping too much. If the old battery drops a lot less, then that points toward the new battery being defective. Not 100%, but pretty likely.

[Dan Bundy]

Thank you again to all for the advice/input/recommendations.

Paul, I do not have the old one. Left it to be recycled. I am going to head back to the battery store (Batteries +) Saturday in hopes of solving/resolving this frustrating issue.

[Bill Dufour]

Not sure if this reads low enough amps for you. Worth risking $20.00 minus the discount this weekend. Or look for something better.
Bill D.
https://www.harborfreight.com/100-amp-612v-battery-load-tester-61747.html

[Jason Hennry]

It's possible for a battery to show a high voltage but lack full capacity. Sluggish performance indicates a potential issue. Consider having the battery's capacity tested, and consult with Kangaroo Golf for further assistance.

[Bill Howatt]

Just had this with my laptop. It would show full charge but the computer kept saying it didn't have the ability to provide enough power (or words like that). Bought a replacement and all is well.

[Bill Dufour]

A bad battery will show full voltage at rest. Load it down and the voltage drops very fast this also reduces amps as well. Not sure if the amps is actually reduced or just lower volts will not push amps out against any load resistance. Not that it really matters the effect is the same. Another sign of a bad battery is it takes a very short time to fully recharge from very low state of charge.
A car battery that drops below about 10.5 volts when cranking will not be able to crank the engine fast enough to start. Probably need a little more volts for older cars with point ignition and carburetors.
All my voltages assume a normal lead acid 12volt car battery.
Bill D