Bad batteries?

[DoubleTake]

Are any of these batteries bad? These are my readings, the last two are newer batteries.

Battery pack reading was between 34.22 and 35 while under load. Sitting still is 37.12. Each battery reading is as follows:
1 - 6.15
2 - 6.17
3 - 6.16
4 - 6.15
5 - 6.20
6 - 6.31

2006 EZGO TXT with D&D High Torque motor, Alltrax SPM500 controller if that matters.

[stang99x]

It depends on when you took the reading. Were they charged and at rest, or had you driven it, etc.
A properly charged rested pack will read about 38.5 at rest, or 6.4 each

[DoubleTake]

Just went and tested them off a full charge, rested, and have not ridden it:

6.28
6.29
6.29
6.28
6.32
6.47

37.91

[scottyb]

Originally Posted by DoubleTake

Just went and tested them off a full charge, rested, and have not ridden it:

6.28
6.29
6.29
6.28
6.32
6.47

37.91

Take a reading as I said 12 & 24 hours AFTER the charge. That is a true measure of what they can hold and ..... get an under load test of each battery #1-6 and see if some of the old ones are dropping lower than some of the new ones.

[DoubleTake]

Originally Posted by scottyb

Take a reading as I said 12 & 24 hours AFTER the charge. That is a true measure of what they can hold and ..... get an under load test of each battery #1-6 and see if some of the old ones are dropping lower than some of the new ones.

OK, I'm just not exactly sure when 12 & 24 hours AFTER the charge is. I can test them tomorrow morning and that should be about 24 hours after a charge.

[stang99x]

Originally Posted by DoubleTake

OK, I'm just not exactly sure when 12 & 24 hours AFTER the charge is. I can test them tomorrow morning and that should be about 24 hours after a charge.

It's 12 hours and 24 hours after removing the charger from the cart. Do you know the years of the batteries beside the new ones? Somewhere around this forum there is a chart that gives you battery life percentages in reference to fully charged level and age. I would guess that yours are probably around 4ish years old, maybe 5. If you want to load test the batteries, you can do the following using caution as you do it. Pull the cart up to a curb and rest the front tires on the curb. remove the seat and have a buddy there to help. Put your voltmeter on each battery and have your buddy push the gas. Take the reading while the cart in "under load" with him pushing the gas. Be careful not to allow the cart to hop the curb and run either of you over. The reading you get is the loaded reading and will tell you if any of them have gone bad. Once you know the loaded voltage report back

[rib33024]

stang99x for someone that calls his self a professional. This is very dangerous for telling members to load test their golf carts this way. There is so much that can go wrong here. I'm not sure where to start. The first rule of electric carts is to NEVER stall the motor. When you are pushing on the go pedal and the wheels are not turning, It only takes a couple of seconds to long and your going to melt something, Battery post, smoke a controller, or a solenoid, burn up the motor. Or a good chance of things going wrong and hurting someone.

I would advise no one to try and load test your cart this way.

[teecro]

Originally Posted by DoubleTake

OK, I'm just not exactly sure when 12 & 24 hours AFTER the charge is. I can test them tomorrow morning and that should be about 24 hours after a charge.

Does not need to be "EXACT" 12 or 24 hours... Let your battery come up to full charge and then let them rest for somewhere close to 12 hours and take a reading of all battery. Without using your cart let it sit another 12 odd hours and get another set of readings. What is being looked for here is to see at what rate your battery are self discharging. According to your readings 5 of your battery are only up to 90 % and one is at 100 % so depending on their age they may be heading down the slope. But as long as you know this you can keep using them as long as they still perform as needed just be sure to keep them on the charger whenever you are not riding....

As to load testing no way in ell would I try stall testing against a curb or wall as that is simply too hard on the equipment period and unsafe if it jumps over.... Hook up your voltage meter across your pack and take your cart out with a friend or two on board and try to find some hills or moderate inclines. What your looking to not see is your pack voltage drop below 31 volts or at least not by much or for long....