48 volt battery question

[gardnerphoto]

Got a 2011 ezgo 48 volt,batteries are 2015,cart has set up for 2 yrs,charge batteries ,get volt reading of 53.2(full charge).I connected volt meter to cart,while riding volts go down to 42 volts, slow ,might run for 20 minutes...Do I need to replace batteries?

[usgicollector]

There toast...

[scottyb]

Agreed - replace the batteries.

[ThreeCW]

The 42 volts is a pretty good indication that your batteries are weak, and the 20 minute run time is pretty poor, but you can do some further testing to determine if it is one battery that is weak or all of them.

2015 batteries are 3 and coming 4 years old and depending on how they were cared for, will determine how long they will last. Most people report 5 years life with reasonable battery care of good quality batteries ... other can stretch out 7 or 8 years. Some people can burn them up in a year, especially with high use and / or poor maintenance.

You mention a full charge of 53.2 volts ... I assume that this is right after charging? To get a more accurate determination of what the batteries are charging to, give them a full charge, disconnect the charger and let the voltage stabilize for 12 to 24 hours. This voltage will give you a reasonable estimate of their state of charge by using the attached chart. Take the static voltage of the entire pack and for each battery in the pack.

Then repeat your voltage testing under load (when driving) again for the entire pack and then individually for each battery (when driving).

You can then compare the static voltage of each battery to the loaded voltage of each battery to determine if one or more are problematic.

"usgicollector" and "scottyb" analysis may be correct that the entire pack needs replacing, but the above "science experiment" will prove it to you.

If you are game, report back the results and we can help you with your analysis (and help a few more people in evaluating their battery health too).

While you are at it, at the end of your road test, check the temperature of each connection in the high amperage cables to make sure nothing is heating up due to a high resistance connection. Touching (carefully) by hand is usually a good enough comparison unless you have an infra-red temperature gun handy.

You might also run them down for the 20 minutes it takes to slow the cart down and take pack and individual voltages again.

The above testing should confirm the state of your batteries.

[scottyb]

The person reported the pack sat unused for 2 years.
In my experience serious damage starts about 6 months in and useful life is severely compromised by 1 year.

[gardnerphoto]

Thanks for all the replies! I am currently charging,will do recommended tests,

New question ,I live in eastern NC.I have a chance to buy February 2018 set of batteries,They were in a cart that flooded ,*Salt water* on coast,some of the terminals are corroded already,(pitted)owner says cart was under water about 2 hrs,(but I do not know for sure),will they hold up? It does not look like salt water got into batteries,Are they worth buying.....?

[ThreeCW]

Originally Posted by scottyb

The person reported the pack sat unused for 2 years. In my experience serious damage starts about 6 months in and useful life is severely compromised by 1 year.

I missed the point of the cart sitting used for 2 years ... thanks for the translation ScottyB ... "cart has set up for 2 yrs" didn't quite translate into Canadian English very well (But I understand the translation now.)

If those batteries sat (set up) for two years with no maintenance, I too suspect that the tests that "gardnerphoto" is planning will confirm that the batteries are in an unrecoverable state

"Gardenerphoto" - Any chance that the batteries are slight or moderately "bulged" near the bottom indicating severe sulfating? What was the voltage of the batteries after the cart was set up for 2 years and before you recharged them?

I can't comment personally on the batteries that have been under water ... but have read some BGW threads on flooded carts where batteries have been salvaged ... and other threads where they have not survived, so they may still have useful life in them. Read up on "Flooded Carts" and you might be able to find some more information.