Buying a used cart, how can I test batteries?

[CartManGA]

This is a great Forum..... I have spent a ton of time here and I don't even have a buggy yet. I am looking at an 08 ish Precedent from a private seller and was wondering what I might do to check out the batteries. I know how to check the age of the battery, but I was wondering if there was anything else I could do. I remember reading here somewhere about a hydrometer??

Any help would be appreciated.

Thanks

[Colbyntx]

You can test them with a DMM and a load tester if you know how to use them. Print off the state of charge sticky and take it with you to compair.

[gornoman]

Digital voltage readings along with hydrometer results will give you a good read of each battery's condition. Also, drive the cart on the same route each time while monitoring the voltage of each battery. They should all drop down to the same voltage level when doing the same task. This will indicate if the pack is balanced.

[CartManGA]

Thanks for the feedback. Which sponsor should I reach out to get the voltage meter and hdrometer?

[scottyb]

You can find a DVM at any big box store. I have a Sperry brand I picked up at a HDepot that was reasonably priced and has been durable. A Floating needle type hydrometer can be found at any auto parts store.
If you can tell the age of the batteries that is probably your best judge of their general worth, average golf cart useful life is 4-5 yrs.

[Colbyntx]

Cartman,

If you are on a budget like most of us are, Wal-mart sells a DMM for $20.00 that will take all the readings you need for a cart. Do not get the hydrometer at Wal-mart(like antifreeze float balls). It is pure junk. Get one at a autopart store that has temp adjustment.

[dougmcp]

IMO you don't need to use a hydrometer, a simple voltage check will tell you the basic condition of the batteries.
Clip a meter to the battery pack, it should be in the 51v range, take it for a drive, if under full acceleration the voltage drops more than 15% (43.2v) you have a battery problem.

[erict]

Originally Posted by dougmcp

IMO you don't need to use a hydrometer, a simple voltage check will tell you the basic condition of the batteries.
Clip a meter to the battery pack, it should be in the 51v range, take it for a drive, if under full acceleration the voltage drops more than 15% (43.2v) you have a battery problem.

Doug, under load is this normal for the pack to drop in the mid 40's. I know if that was a state of charge reading the batteries would be toast.

[dougmcp]

Originally Posted by erict

Doug, under load is this normal for the pack to drop in the mid 40's. I know if that was a state of charge reading the batteries would be toast.

It's normal under full acceleration to drop that low.
After driving the cart, you can only really take an accurate voltage reading after the cart has been sitting idle for a couple of hours.

[erict]

Originally Posted by dougmcp

It's normal under full acceleration to drop that low.
After driving the cart, you can only really take an accurate voltage reading after the cart has been sitting idle for a couple of hours.

Thanks Doug.

Another question, on a 48v cart 50.93 is 100% charged. A 90% charge is 50.47. How do they arrive at that figure of 50.47 being 10% less then 100%