batteries bad?

[leapingbuddha]

My batteries are a couple 3 years old... My solar top 350 watts charges them. In the day the voltage is 41 volts ...in the morning its 38 volts. my spacific gravity seems to be good. all cells are very close readings..........when I accerate the voltage drops to 29 volts and the acceleration is slow.... can only travel a quarter mile and then limp home.... now batteries say good voltage... what gives. dirty tirminals? or something else............thanks

[leapingbuddha]

batteries about 3 years old ...........voltage good and specificgravity all close to each other.....so my voltage drops on acceleration to 29volts and is very slow on acceleration.....500 yards and am slowing down and limping home............dirty terminals?

[trig123]

Originally Posted by leapingbuddha

batteries about 3 years old ...........voltage good and specificgravity all close to each other.....so my voltage drops on acceleration to 29volts and is very slow on acceleration.....500 yards and am slowing down and limping home............dirty terminals?

Did you load test them ? sounds like you got one or more bad. What is the pack voltage after charging ?

[leapingbuddha]

41 volts and the SG is real close on all cells

[cgtech]

The "500 yards & limping home" screams "bad batteries" to me. If it were a cable connection doing this, it would be smoking hot at 500 yards (and wouldnt recover).

[handtools]

My batteries are a couple 3 years old... My solar top 350 watts charges them. In the day the voltage is 41 volts ...in the morning its 38 volts. my spacific gravity seems to be good. all cells are very close readings..........when I accerate the voltage drops to 29 volts and the acceleration is slow.... can only travel a quarter mile and then limp home.... now batteries say good voltage... what gives. dirty tirminals? or something else............thanks

If you have only been using the solar panel to charge the batteries for 3 years I would say you have been chronically undercharging them. Do you have a regular charger that you can use to charge them with? If you do, try doing several back to back charge cycles to see if you can bring them back a little.

[rockfordpi]

Originally Posted by handtools

My batteries are a couple 3 years old... My solar top 350 watts charges them. In the day the voltage is 41 volts ...in the morning its 38 volts. my spacific gravity seems to be good. all cells are very close readings..........when I accerate the voltage drops to 29 volts and the acceleration is slow.... can only travel a quarter mile and then limp home.... now batteries say good voltage... what gives. dirty tirminals? or something else............thanks

If you have only been using the solar panel to charge the batteries for 3 years I would say you have been chronically undercharging them. Do you have a regular charger that you can use to charge them with? If you do, try doing several back to back charge cycles to see if you can bring them back a little.

I to have to wonder if you can get by with only a solar charger. To be fair, I have never looked closely at those. However, a 36v charger at 15 AMPs is putting 540 watts into the battery.

Assume a 36 volt cart pulling 50 amps (which is low, just using round numbers, actually it is three times that when first starting). That is 1800 watts which is around 2.5hp (1hp is roughly 750 watts). So, VERY roughly speaking, you need 5 hours at 350 watts to generate 2.5 HP (1800 watts) for one hour.

You can only get out what you put in (actually less because no charging system is 100% efficient, you have loss in transfer). My numbers above a VERY rough calculations used for example only, they do not take into account efficiency. Also, how many hours per day does the Solar Panel produce the full 350 watts?

Like the poster above mentioned, I would guess your batteries are never getting fully charged as over time you are constantly removing more than you are putting back.

[Forklift]

I would load test the batteries individually.

One bad battery will kill the set.

[scottyb]

41v is nowhere near where the batteries need to be during recharge. The batteries are sulfated (dead) from chronic undercharge. They can no longer take or give large quantities of amperage.
I'll guess every one will fail a true load test using a golf cart and meter.