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48 volt golf cart problem

RiverDave

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I used my golf cart for a real estate video a month or two back and ended up leaving it in the garage. It was plugged in so no worries..

Well golf cart chargers charge for a period then shut off. I musta left the stereo on or something because all the batteries are completely dead. So much so that the charger won’t kick on to charge them.

The batteries are 8 volt.. I’m guessing I’m buying all new batteries but I figured I’d ask if anyone had a solution before I go that route

IMG_5620.jpeg



RD
 

rivermobster

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They can't all be bad!

Separate em all and test em one at a time.

8v? Really?

Edit: I just looked up the prices on 8v batteries. 😱😱😱
 

JUSTWANNARACE

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Shock the battery. They have dropped below 2v and will require being shocked. I have shocked alot of 6v batteries with great success so I'm assuming you could do an 8v too🤷🏻‍♂️ I just used jumper cables from my truck usually after a minute or 2 you can hook the charger up and it will recognize the battery. It works on Li-Ion batteries also.

Just a thought.
 

mesquito_creek

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Start with a volt meter. Check the total in series battery bank (48v) and then do each separately. Most likely they can be charged but the battery charger isn’t going to kick on if the bank is below what the charger needs to tell it that it’s safe to charge.

The battery charger should have a sticker or placard that gives the input and out range.
 

RiverDave

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Shock the battery. They have dropped below 2v and will require being shocked. I have shocked alot of 6v batteries with great success so I'm assuming you could do an 8v too🤷🏻‍♂️ I just used jumper cables from my truck usually after a minute or 2 you can hook the charger up and it will recognize the battery. It works on Li-Ion batteries also.

Just a thought.

Hook a 12
V to an 8 v?

Really?
 

mesquito_creek

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Without knowing the voltage of each battery you are just guessing. It could be as simple as a battery charger that is bad.
 

mesquito_creek

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You could leave it as is and wire up 4 - 12v in series and wake up the battery’s and charger..
 

JUSTWANNARACE

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Hook a 12
V to an 8 v?

Really?

Look at the charge rate of a 12v battery. Sometimes up to 16v-18v especially on old chargers(the good ones that are not "smart").. 13.5v-14v (what you car when started is most likely) is not going to hurt those 8v hitting them for a short period of time to "wake them up". Will you have to do each on individually, yes. Will it save you thousands in batteries, most likely. They didnt just "go bad" in a couple weeks. They are just in "sleep mode".
 

Motor Boater

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The 48v charger won't charge if the batteries are too low. You need to charge them Individually with a stand alone charger. I'd imagine a 6v charger would work

This is the answer. I’ve had it happen to me several time. Charge each battery individually and then plug the regular charger in. Run the shit out of it. Charge batteries again. Put water in them.
 

Luvnlife

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Dave I’ve had this problem. The bats are so drained that they won’t signal the charger to turn on. Take the cover off the charger, plug the cart in. When you look at the charger it kinda becomes self explanator. You have to jump a wire. I don’t remember which one but follow the wiring and you should be able to figure it out, I did.🤔👍🏻🍺
 

WTR&PWR

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if you know someone that has another 48 volt cart, use that to "jump" yours to bring the batteries up enough to get the charger going. have your charger going while doing this.
I agree. Have a buddy with a 48v come by and hook up jumper cables then Plug your charger in for awhile.
 

C-Ya

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The 48v charger won't charge if the batteries are too low. You need to charge them Individually with a stand alone charger. I'd imagine a 6v charger would work
This is the answer…….

Just thought I would 2nd, the correct fix, to the problem.
 

500bbc

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The 48v charger won't charge if the batteries are too low. You need to charge them Individually with a stand alone charger. I'd imagine a 6v charger would work
If it's a smart charger you don't need to do all the batts or bring them to full charge. Just enough that the charger reads low charge.
 

mesquito_creek

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While 48v in general isn’t going to kill you, it is only a few volts away from killing you. Any attempt to hook up additional batteries without determining what the current state of charge is and checking the voltage is weak advise.

Could have a blown fuse, broken ground strap, burnt wire, bad battery connection etc etc

48v is safe but way less so than 6 or 12v systems.
 

WYRD

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The 48v charger won't charge if the batteries are too low. You need to charge them Individually with a stand alone charger. I'd imagine a 6v charger would work
This is the answer…….

Just thought I would 2nd, the correct fix, to the problem.
X3 you can quit looking because this is the correct answer charge them all individually at 6 volts then connect them all back up and series and plug in your 48 volt charger.
 

riverroyal

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Look like Trojan batteries. How old are they? Mine did this last month.
They were 4 1/2 years old.
Figured that's a really good life so I opened the wallet and cried
 

JUSTWANNARACE

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Your buddies cart isnt going to jump yours. Have you ever been successfulruning jumper cables from a bare battery to a car and having it start? Most likely not if that low. In all reality you my only have one battery causing the issue. Draw a diagram of the series wires, pull wires and check voltage of each battery. If below 2-5v (most likely the one is 2v or below) hit it with jumper cables and be done. Then charge them individually. But I will say that if has dropped to low on any battery, that battery will not even recognize a regular 8v individual charger without shocking it.. JMO
 

rrrr

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If you connect an individual battery to a 12 volt charger, its 14.4 volts will put a 3.6 volts per cell charge on the 8 volt battery. That's not excessive if it's run for two 15 minute sessions with a break in between to prevent over temperature. You just need to monitor the battery's temperature and make sure the electrolyte isn't offgassing excessive hydrogen. Do this outdoors, so there's less danger of hydrogen accumulation.

That much charge current will actually be beneficial, because it will act on the lead sulfate collected on the plates during the discharge and help restore the electrolyte chemical balance.

That should bring the battery's open circuit voltage up to the point that when they're all charged together with the 48 volt charger it will activate.

I installed and operated a few flooded electrolyte lead acid batteries back in the day, so I'm not just making this up.

MC-Lane-fig1-900x550.jpg
 
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mesquito_creek

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It seems like a low voltage disconnect could go along way to saving the batteries on these golf carts? Is there a reason they don’t have them?
 

Motoxxxloak

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Just got off the water so haven’t read all the replies. I believe 48v chargers are all diff. Some won’t kick on unless there is 40v pack voltage. Some are 35. My recommendation is charge each one individually if you have a battery charger and go from there.
 

oldman

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If you connect an individual battery to a 12 volt charger, its 14.4 volts will put a 3.6 volts per cell charge on the 8 volt battery. That's not excessive if it's run for two 15 minute sessions with a break in between to prevent over temperature. You just need to monitor the battery's temperature and make sure the electrolyte isn't offgassing excessive hydrogen. Do this outdoors, so there's less danger of hydrogen accumulation.

That much charge current will actually be beneficial, because it will act on the lead sulfate collected on the plates during the discharge and help restore the electrolyte chemical balance.

That should bring the battery's open circuit voltage up to the point that when they're all charged together with the 48 volt charger it will activate.

I installed and operated a few flooded electrolyte lead acid batteries back in the day, so I'm not just making this up.

MC-Lane-fig1-900x550.jpg
Looks like the battery banks at our substations.
 

El Rojo

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Like everyone said isolate a a battery or parallel 3 and use a 24v charger (some roller chargers have a 24v setting) and charge them so them so your charger will kick on and charge the pack. If batteries are still good get a smart charger...better yet if batteries are toast convert to lithium ion for cheaper than a pack of 6 8v acid batteries....
 

Taboma

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Tested the volts on each.. we r buying new batteries lol
I've brought mine back numerous times over the years, just because they're showing dead doesn't mean they can't be recharged. Just don't allow them to sit in this state for long if possible. I had to re-charge mine from almost zero so many times because I never left them on a charger for months, I installed a switch and by-pass relay to override the minimum voltage prior to charging criteria.
That relay is basically a safety so the charger won't energize and shock you, it has to be connected to batteries with sufficient voltage to engage the relay in order to output voltage. So NO unlike the movies you can torture somebody with 48 volts.
In your case I'd do as rrrr suggested, bump each battery up individually with a 12v charger in stages until the read maybe 5 - 6V each. Assuming you have a charger that will energize with almost no voltage present. If not you could start the 12V charger charge by paralleling another 12V battery for a few minutes.
Collectively that should reach the minimum your charger needs to see in order to close the safety charge relay.
 

coolchange

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If you didn’t go to zero, and they’re not sulfided they should come back
 

Taboma

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By the way, if any of you have older EZ-Go 36V carts, with older non solid state chargers, here's the wiring diagram and associated pics with the by-pass switch and relay I installed in my charger to by-pass the safety and allow it to energize with essentially zero battery voltage.
After 30 minutes or so I'd switch it back to normal and allow it to continue to auto-charge as necessary.
Over the years I ended up loaning to a few neighbors who encountered the "insufficient voltage to initiate charge problem."

Golf Cart Charger By-Pass.jpg
 

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mesquito_creek

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My 36v cart has one. But if someone ties lights or a stereo direct to the batteries it bypasses that.

Are there 36/48v stereos and lights? I know there are but as a practical matter many many more at 12v. So there must be a step down transformer on the cart to use 12v stuff. Does anyone know if you can hook 12v to the transformer and get 48v on the other side?

IMG_0258.jpeg
 

oldman

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Are there 36/48v stereos and lights? I know there are but as a practical matter many many more at 12v. So there must be a step down transformer on the cart to use 12v stuff. Does anyone know if you can hook 12v to the transformer and get 48v on the other side?

View attachment 1429393
probably could, unless there is a diode stopping it.
A transformer doesn't know the difference, voltage in voltage out.
 

Taboma

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So you pulled all the cables? Why not just try to restore the batts you have if you have gone that far?
Why is checking individual battery voltage cause for assuming he pulled the cables ?🤔

You can still test from the pos to neg terminals on each battery , or several, without lifting a single cable.
 

Taboma

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Are there 36/48v stereos and lights? I know there are but as a practical matter many many more at 12v. So there must be a step down transformer on the cart to use 12v stuff. Does anyone know if you can hook 12v to the transformer and get 48v on the other side?

View attachment 1429393
wasn't any step down on mine, 12v lights as an example were simply tapped off one of the 3 pairs of 6V batts on my 36v system. I could see that if it was a substantial load, but otherwise the batteries will tend to self-equalize anyway when one gets drawing down more than the others in series with it.
 

mesquito_creek

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probably could, unless there is a diode stopping it.
A transformer doesn't know the difference, voltage in voltage out.
wasn't any step down on mine, 12v lights as an example were simply tapped off one of the 3 pairs of 6V batts on my 36v system. I could see that if it was a substantial load, but otherwise the batteries will tend to self-equalize anyway when one gets drawing down more than the others in series with it.

In case you were wondering… I hooked up a 12v battery on a charger to the 12v side of the step down transformer and only got 12.8v on the 48v side of the transformer, so that doesn’t work…. Never mind! Lol
 
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