48 volt golf cart problem

[Big B Hova]

I'm disappointed in this outcome. I wanted to see the diagnostics Dave!

 

[JUSTWANNARACE]

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.

So you are telling me you can test each battery individually without pulling cables? Hmm..

Weather wired in series or parallel you will not get a correct reading with the cables on. You are getting current from the battery its connected to.

You know alot more about "electrical" then I do. I am just speaking from experience. I have done my fair share of batteries in parallel and in series and this is my experience. Pull the cables and isolate the battery and you will get a different reading then with the cables hooked up. JMO

 

[RiverDave]

So you pulled all the cables? Why not just try to restore the batts you have if you have gone that far?

The volt meter didn’t even register on all but 2 batteries. The two it did one read 2 volts and the other read 4

 

[RiverDave]

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.

This is what I did

 

[JUSTWANNARACE]

The volt meter didn’t even register on all but 2 batteries. The two it did one read 2 volts and the other read 4

I bet you could still bring them back. But that's just me cause I'm poor

 

[Taboma]

So you are telling me you can test each battery individually without pulling cables? Hmm..

Weather wired in series or parallel you will not get a correct reading with the cables on. You are getting current from the battery its connected to.

You know alot more about "electrical" then I do. I am just speaking from experience. I have done my fair share of batteries in parallel and in series and this is my experience. Pull the cables and isolate the battery and you will get a different reading then with the cables hooked up. JMO

You measuring current or voltage ? You can certainly read individual battery voltage regardless of how they are connected so long as you can access each of the batteries terminals. In parallel, voltage is constant, meaning a dozen 12V batteries in parallel will still read 12V, but the current amp hours is additive.
In series, it's just he opposite, with combined voltage being additive and current being no greater than any single battery.
I can't explain why you're results varied unless I witness your testing methods.

 

[Taboma]

This is what I did

That's how you do it sir.
Having recovered mine from near death more than I can recall, if you can bump them up sufficiently to satisfy your charger's minimum, you might be pleasantly please as these types of batteries are damned hardy.

 

[j21black]

I had to put my individual batteries on a normal battery charge for a while to get them with enough charge for the cart charger to take over.

 

[mesquito_creek]

The volt meter didn’t even register on all but 2 batteries. The two it did one read 2 volts and the other read 4

Makes you wonder how the digital dash meter got 5v?

Man with 2 watches never knows what time it is!

 

[stoker2001]

work at prison where we have fleet of 70 carts to maintain..The charger in pic is Modern Lester Summit2 bluetooth.very good charger!If those trojans are less the four years old,i would try to individually stimulate them with car charger that has start-mode and try to get each 8V to come up to at least six volts or more.Put cart in TOW mode and disconnect main negative pack cable and leave rest cables connected while trying to zap each individually.If that dont work,do as others said and go with single lithium that are rated at 51-52V..you will save TON of wieght and cart will pick up few MPH with faster charging and longer run time

 

[oldman]

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

Did you check voltage on the charger, If it's not hooked to a real battery it won't put out 12v

 

[mesquito_creek]

Did you check voltage on the charger, If it's not hooked to a real battery it won't put out 12v

Yep… fully charged 12.8v battery plus a 4.5 amp charge.

 

[rivermobster]

I'm disappointed in this outcome. I wanted to see the diagnostics Dave!

I told him where to start, but I haven't heard anything!

The easy diagnosis would be to take to a shop that has a Midtronics tester.

Dead or fully charged, a Midtronics will tell you if the battery is good, or not.

Every Interstate Battery store has one.

 

[Big B Hova]

I told him where to start, but I haven't heard anything!

The easy diagnosis would be to take to a shop that has a Midtronics tester.

Dead or fully charged, a Midtronics will tell you if the battery is good, or not.

Every Interstate Battery store has one.

I got a cheap Napa one with the guage, but it works. I was able to tell which of my batteries had a peoplem

 

[rivermobster]

I got a cheap Napa one with the guage, but it works. I was able to tell which of my batteries had a peoplem

Cool. I didn't know they have cheap Midtronics testers now.

Amazon.com

 

[Big B Hova]

Cool. I didn't know they have cheap Midtronics testers now.

Amazon.com

I was talking about this bad boy

 

[oldman]

Yep… fully charged 12.8v battery plus a 4.5 amp charge.

It's probably a solid state unit then not a true transformer. So that makes sense. You won't be able to backfeed it.

 

[WTR&PWR]

Especially in havasu heat make sure they are topped off with distilled water and throw on the charger. I usually do this twice a year with Trojan batteries and they sit in the carport. The last ones still lasted 6 years and were still usable but we have some hills at the springs where they were starting to show age. If you want to save the money you can definitely bring them back. They are worth more than the core charge if you want to sell them.

 

[RiverDave]

I had to put my individual batteries on a normal battery charge for a while to get them with enough charge for the cart charger to take over.

How do you do that when they are eight volt batteries?

 

[rrrr]

How do you do that when they are eight volt batteries?

You could read the post I made above.

 

[j21black]

How do you do that when they are eight volt batteries?

I don't remember excatly how I did it - Was 12 years ago -

Guy was coming to buy the cart the next day and the battery charger wouldn't kick on. This got enough charge in them to kick the charger on.

I think I had 4 12V Trojan batteries, but it has been a while.

 

[WYRD]

How do you do that when they are eight volt batteries?

Put the black wire on the negative post, red wire on the positive post, turn the charger on 2amp charge

 

[RiverDave]

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.

Thank you I will try this.. you think they might come back even though they are zero volts?

 

[mesquito_creek]

if you want to really confuse people… on a 48v lithium battery… 58v is fully charged and 46-48v is practically dead. All the capacity is around 52v.

 

[yz450mm]

How do you do that when they are eight volt batteries?

Get a manual 12/24V charger, a hydrometer, and a load tester. Check water levels and fill with distilled as needed. Don't overfill.

Put the charger in 24V mode, connect the positive lead to the positive terminal of battery 1, and the negative lead to the negative terminal of battery 3. We will call this bank one, and will be batteries 1,2, and 3. Do this again for bank two, or batteries 4, 5, and 6. Battery 1 will have your positive lead going to the cart, and battery 6 will have the negative lead for the cart.

Once all the batteries have some charge/voltage, disconnect the charger and hook up the automatic cart charger. Let it complete a charge cycle, then disconnect. Grab your volt meter and check each battery individually, then the series (positive of battery 1 to negative of battery 6).

Use a load tester and hydrometer on each battery bank (123, 234, 345, 456) to check for bad batteries/dead cells. One dead cell on a battery will "soak up" energy from the other cells, so although that battery might show a good surface charge, it's dead.

https://www.napaonline.com/en/p/NBCSC1633?cid=paidsearch_shopping_dcoe_google_monthly-special_202409&campaign=GSC-Promos&campaign_id=6478906937&adgroup_id=78844950918&adtype=pla&gclid=Cj0KCQjwrp-3BhDgARIsAEWJ6SwouDuhyYuhJP0U-ucI7oLIh6xNuoqbicIbEbsRIZhLul0Jw1EVeEMaAhWrEALw_wcB&gclsrc=aw.ds&gad_source=1

https://www.harborfreight.com/1000-amp-dc-61224v-carbon-pile-battery-and-system-load-tester-58933.html

 

[j21black]

Thank you I will try this.. you think they might come back even though they are zero volts?

Mine did.....

 

[Big B Hova]

if you want to really confuse people… on a 48v lithium battery… 58v is fully charged and 46-48v is practically dead. All the capacity is around 52v.

 

[rivermobster]

I was talking about this bad boy View attachment 1429441

Load testers only work on fully charged batteries. They won't tell you much about a dead battery!

 

[rrrr]

Thank you I will try this.. you think they might come back even though they are zero volts?

It's likely. In the end a lead acid battery relies on a chemical reaction created by the properties of the electrolyte and plates. Introducing electrical current into that equation restores the proper balance, but sometimes the damage done by a deep discharge is fatal.

Try it on one battery and see what happens. You'll need an old school 12V charger that uses a transformer, inductors, and diodes to produce the current. If it has a switch that changes the charge amperage, put it on the max, usually ten amps. If the charger shuts off on overload, choose a lower setting. The newer electronic models need a sufficient turn on voltage to operate.

As @Taboma said above, it's not necessary to disconnect any interbattery cabling. Just hook the charger to the positive and negative posts of a single battery and let 'er rip.

 

[Taboma]

Load testers only work on fully charged batteries. They won't tell you much about a dead battery!

I've had it reveal that the decent appearing voltage reading following a good charging, might power a led bulb, but under the stress of a load tester fails miserably.

 

[rivermobster]

I've had it reveal that the decent appearing voltage reading following a good charging, might power a led bulb, but under the stress of a load tester fails miserably.

And that's exactly what they are for.

 

[rrrr]

And that's exactly what they are for.

Those cheap 100 amp load bank testers provide good information if you know what to look for. The analog meter version is OK, one with a digital readout is better. Over a 30-45 second test, a fully charged and healthy 12 volt battery will begin at 12.7 or 12.8 volts, and under load will drop to 10.5-11 volts immediately.

Then the voltage will recover slowly over the next 10-20 seconds to 12.2-12.4 and stay there. Running the tester for more than 45 seconds to a minute isn't necessary, it has given all the information that simple device provides. But it shows the battery is healthy and has a good discharge profile.

I don't care for the rollaround type load testers. They can put a max load--800 amps or more--on a battery, and if used improperly, can drastically shorten its life. Case in point, two different batteries in my wife's Acura TL failed about a month after the service apes at the dealer performed a load test on them. I suspected the tech didn't know what he was doing.

 

[oldman]

Those cheap 100 amp load bank testers provide good information if you know what to look for. The analog meter version is OK, one with a digital readout is better. Over a 30-45 second test, a fully charged and healthy 12 volt battery will begin at 12.7 or 12.8 volts, and under load will drop to 10.5-11 volts immediately.

Then the voltage will recover slowly over the next 10-20 seconds to 12.2-12.4 and stay there. Running the tester for more than 45 seconds to a minute isn't necessary, it has given all the information that simple device provides. But it shows the battery is healthy and has a good discharge profile.

I don't care for the rollaround type load testers. They can put a max load--800 amps or more--on a battery, and if used improperly, can drastically shorten its life. Case in point, two different batteries in my wife's Acura TL failed about a month after the service apes at the dealer performed a load test on them. I suspected the tech didn't know what he was doing.

Carbon pile tester?
where they can crank on the load to failure.

 

[riverroyal]

Whats age are they? Did I miss that.
If they are 4 years old fuck it get new ones

 

[rivermobster]

Those cheap 100 amp load bank testers provide good information if you know what to look for. The analog meter version is OK, one with a digital readout is better. Over a 30-45 second test, a fully charged and healthy 12 volt battery will begin at 12.7 or 12.8 volts, and under load will drop to 10.5-11 volts immediately.

Then the voltage will recover slowly over the next 10-20 seconds to 12.2-12.4 and stay there. Running the tester for more than 45 seconds to a minute isn't necessary, it has given all the information that simple device provides. But it shows the battery is healthy and has a good discharge profile.

I don't care for the rollaround type load testers. They can put a max load--800 amps or more--on a battery, and if used improperly, can drastically shorten its life. Case in point, two different batteries in my wife's Acura TL failed about a month after the service apes at the dealer performed a load test on them. I suspected the tech didn't know what he was doing.

That musta been a long time ago??

Every dealership worked at REQUIRED a Midtronics printout for every battery replacement.

I haven't worked in a dealership for over 15 years now?

I can't imagine Any dealership that would even have a load tester today.

Way too dangerous.

 

[rrrr]

That musta been a long time ago??

Every dealership worked at REQUIRED a Midtronics printout for every battery replacement.

I haven't worked in a dealership for over 15 years now?

I can't imagine Any dealership that would even have a load tester today.

Way too dangerous.

This is what the Acura dealer used. The car was a 2008 TL. After her second battery shit the bed, I went to the dealer and asked some questions. I'm confident user error was involved.

They didn't replace the batteries, they failed sometime later. There wasn't anything wrong with the charging system, both batteries were 18-30 months old IIRC. Both had intercell connector failures, a good indication they were improperly loaded.

https://www.autometer.com/bva-34-800-amp-variable-load-battery-electrical-system-tester.html

 

[rivermobster]

This is what the Acura dealer used. The car was a 2008 TL. After her second battery shit the bed, I went to the dealer and asked some questions. I'm confident user error was involved.

They didn't replace the batteries, they failed sometime later. There wasn't anything wrong with the charging system, both batteries were 18-30 months old IIRC. Both had intercell connector failures, a good indication they were improperly loaded.

https://www.autometer.com/bva-34-800-amp-variable-load-battery-electrical-system-tester.html

You are most likely correct. That thing looks pretty scary!

Not something I'd want any of my techs to use. Sheesh.

 

[Badchoices03]

My stepdad left his stereo on his 48v cart overnight and the batteries completely died, same deal as you, dead and charger wouldnt kick on...batteries werent even a year old yet...so he bought an 8v battery charger off of Amazon for like $30 and charged each battery enough so that the cart charger would work....

Also, not sure how, but yearsssss ago I had a 48v cart, same thing happened to me, batteries drained completely...at the time I had a buddy that worked on golfcarts...he came over and opened up the cart charger and removed a small jumper wire, he said the jumper is what made the charger "smart" by knowing when to turn on and when to turn off, by removing it the charger turned on as soon as it was plugged in, and would never shut off until you unplugged it....so we plugged it in the cart like that for about an hour or so, then put the jumper wire back on....and it worked fine after that....now don't ask me what wire that was, or if its applicable to all chargers....