Battery State of Charge Tables

trigger1937

I've searched and found the "State of Charge" table but it immediatley brings up a big question. These reading are for New Batteries, Open Circuit, and I assume,..some about of time after a charge. a

However, new batteries are only NEW for the first week,.. and as many have posted they have a BIG break in effort to really get them fully charged.

Most of us on this web site have USED our carts and whatever period of time has gone buy, they will never read voltages like a new battery.

So the question is,... for a 12Volt trojan voltage, what would be the voltage I would expect to see "8 hours" after my charge does it's best" My point is this is my starting point for the next days golf cart driving,..and if I want to "NEVER DISCHARGE THE BATTERY DOWN TO 50%",...JUST WHAT VOLTAGE WOULD THAT BE.

It would be great to have a chart of voltage and Percentage and years of age. Of course these would be average based on experienced owners.

I have 4 Trojan's that are all 1 -1/2 years old. All of the voltages range from 12.60 to 12.24 so some of them are starting off at 60% to 70% of charge before I even use them. For one round of golf I know they will end up down below 12.00 volts or 40% range.

I'm in the process of replacing the one battery that is the worst,.. but I really want to "Extend the use of these batteries" until the middle of next year.

Does anyone have experience in Extra charge cycles. In other words,. I charge the cart the day I come home on Monday after golf. Then it sits until Wednesday morning till the next round of golf. I could charge it a 2nd time on Tuesday night. That will at least get them back up to a higher state of charge before I use it.

BGW

__________________
This advertising will not be shown in this way to registered members.
Register your free account today and become a member on Buggies Gone Wild Golf Cart Forum

Stevec3201

I find it shocking that they are only 1 1/2 years old and going bad already. Were you the original owner? Mine are a few months old now and after charging each battery shows 12.76 volts after an overnight rest.

What date are your batteries stamped? I'm curious.

72volt_ezgo

trigger1937- The SOC voltage is completely independent from age of battery.

If you have a brand new 6V battery that has not been charged or discharged (left alone) for say 12 hours and it's voltage measures 6.05V,it is 50% charged.
If this is a 5 year old battery in the same scenario it is still 50% charged.

A true battery test is load testing the battery and see how the voltage holds up then. I think that might be what you are mixing it with.
An open circuit voltage test is nothing but a state of charge test and that is regardless of battery age! It will not give any information on battery condition! Just state of charge.
Barna

scottyb

P.S.
Your batteries are bad. 8 hours after charge they are still in a falsely raised state of charge... the charger brings the batteries up to 60v so if you are not reading 100% 12 hours later, 12hours being the accepted time to settle from charging, then your batteries are loosing their ability to hold a charge due to plate deterioration.
5 yr old batteries are still judged by this chart. Some might say well the battery just holds 75% of it's charge. Well if 50% is empty, then the run time has been reduced by 50%. Except that old batteries tend to give up their charge voltage faster than healthy batteries because of their reduced amperage capacity. So, the 50% becomes 30-40%. and that is why we replace batteries that do not come up to a full charge.
A specific gravity and a runtime test by a GC draw-down machine would give the full picture of your battery condition.
Recheck your pack voltage after 2 days sitting and see how much they really can hold. The pack should loose 1% per day. And yes you can double charge, Monday and Tuesday to use it on Wednesday without harm. I sometimes double charge back to back if I feel the pack needs a boost.

trigger1937

Steve3201,... To repond to your question about the battery age,... yes they are 2010 month of May batteries. I got the cart over a month ago and it came from a Golf course down in Palm Desert. Obviously it had really bad care in the case of the batteries. The rest of the cart was in good shape. In fact, the Golf course had already replaced the batteries via warranty from Club Car in 2010,..that is how they got 2010 batteries in a 2008 Club Car. This is perfect evidence of how anyone can ruin a set of batteries by not taking care of them properly. I'm sure they did not do any "Break in perios",... and as I have indicated in other posts about this cart, the batteries have very bad sulfation and the plates are bulging.

From the other posts,... it seems to me that the SOC doesn't provide a lot of information. The test is what is the voltage after 10+ hours of resting. However 2 of my batteries seem to be in pretty good condition and I'm about to get rid of the one that is the worst. Hopefully if I get them more balanced then the charging will keep them balanced.

scottyb

Balance is the right direction to look. Balance between batteries in a pack should be 1/10th of a volt. Balance between cells within a battery is also very important, measure this by specific gravity. No cell should 30 points from another within a battery.

Hope this helps. And yes I have seen batteries completely ruined in 18 months. It can be done. I have also seen them still going after 9 years....

Stevec3201

Wow! You are right on. I bet those batteries sat low on charge for long periods, as that's the only way to kill them so fast, other than not checking the water levels. Probably a combination of the two, so sad. Good luck with your balancing act!

trigger1937

Thanks again for all the contributions. I played golf today but did not have time to measure the volts before I left. I forgot it was an 11 o'clock shotgun. Beautiful day to day,..sunny all day, no wind, started off with a sweater at 11:00am but took that off after a few holes. Got so warm I had to drop the windshield. Today was our "Turkey Tournament". 3 guys against 3, matched by handicaps, in a scramble. We were down one stroke after 15 holes and one of my partners made a long birdie put to win the 16th hole and now we were tied going into the 17th. My other partner made a great shot 3' under the pin on the 17th and made the put for another birdie and now we were one up on the 18th. Everyone made great shots on the last how and we all tied that hole so my group won the turkey shoot,... a $20 gift card for a Turkey.

After I got home I measured the cart volts and here is the data. 1-12.40, 2-11.07, 3-10.31, 4-12.06. It appears I have another battery besides number 3 that needs replacing. Please,...no suggestions that it is time to buy a new set of batteries.

Colbyntx

Man, you need a new set of batteries! Oh wait, you didn't want to hear that!

gornoman

Looks like it's time for a new set of batteries.