new batts. ,weak ride

[kuntreebouy]

i bought a 1991 ez go cart, the guy i got it from had brand new batts. put in it a month before i got it , he said to only charge it for 3 hrs at a time, but it feels weak ,i just joined the forum ,i started looking around and have found a thread that says to charge batts longer when you 1st get new ones installed, 12 hrs a time and then 5 to 6 hrs each time after the first 15 to 20 charges, but im wondering , have i already screwed up the new batts. by undercharging them at 3 hrs per charge? It is really gonna suck if i have bcuz i dont have the money to replace them, any response is greatly appreciated!!!!

[JohnnieB]

Which charger do you have? (If you don't know, a picture of faceplate will help ID it)

If it is an automatic type, just hook it up and let it shut itself off automatically.
If it is a manual type, monitor the pack voltage and for a 36V battery pack, charge until it reaches 45V.
(Automatic chargers turn off in the 44V to 46V range)


How long to charge a battery is almost impossible to define since time is only a part of the equation. Other parts are what is the beginning State of Charge of the batteries, what is the charge rate (Amps), what is the charge profile of the charger, what is the efficiency of the charge process for the specific batteries and what is the temperature of the electrolyte, just to name a few.

The former owner did you a disservice by just telling you to charge the batteries for three hours and all you can do is go forth and charge your batteries correctly from now on.

Since all the variables remain fairly constant for a specific set of batteries being charged by a specific manual charger, you can build a chart of how many hours to charge based on the starting State of Charge.
Record the battery pack voltage (State of Charge) before charging and note how many hours it take to reach 45V.
After doing the at several different %SoC, you'll have a pretty good idea of how long to charge when the %Soc is 80% or 70% or whatever.


Here is a State of Charge chart. The voltages given are take after the batteries have rested (Neither used nor charged) for about 12 hours or more.

Please note that the 45V mentioned previously is a rapidly and non-linearly depleting "surface" charge that flooded lead-acid batteries acquire during the absorption phase of the charging process and is not reliable for determining State of Charge, so voltage measurements take too soon after the batteries are taken off charge will be off the top of the charts.

Another thing to keep in mind is that the higher average SoC you maintain, the longer your batteries will last before they have to be replaced.

For more info, go to this site and read everything with the word "Battery" in title.
http://www.cartsunlimited.net/

[kuntreebouy]

the charger just tells how many amperes its putting out and a knob to turn for the amount of time to charge , up to 12 hrs , but thanks for the soc info, its much appreciated

[kernal]

If the charger is the original one that came with the cart, it is likely an automatic charger even though it doesn't look like it. A picture of the charger or at least a description would help. Does it have a green face? Is there a model no. such as 20484?
Try this:


Operation: With the charger plugged into an AC source (wall outlet), turn the timer fully counterclockwise to the off position. Plug the cord into the cart receptacle and you should hear the charger "click". Now turn the timer fully clockwise to the start position and observe that the charger comes on (hums) and the amp meter jumps to approximately 20 amps. The amps will slowly decrease down to 1-3 amps as the batteries reach full charge. The charger will completely charge the batteries and automatically shut off when complete and the timer will stop indicating how long it took to charge the batteries. This is for info only but can help with trouble shooting. Normal charge time is 6-10 hours. If the charger runs the full 12 hours I would consider this abnormal and suspect a problem with the charger or more likely the batteries.
The charger will charge for a maximum of 11 hours when set at "1" , 10 hours when set at "2" and so on.
If AC power is interrupted, the charge cycle will continue normally for the remainder of the cycle when power is restored.

[madoc1]

for some really good info and how to break them in, go to cartsunlimited site and read up on batts. he is a sponsor and his site can be found at the top under sponsors.
and welcome to BGW!

[kuntreebouy]

The model num. is 3620A the maker of it is the christee corporation Its got 2 -30 amp fuses in the front, and its been spray painted black, so im not sure what the original color of it was,new laptop i took a pic of it but I just got a different laptop and i havent figured out were my pics are going to on this thing yet