Another battery question

[sleepyluke]

Ok, I can't quite seem to find my issue, but I am sure someone here has seen it before.

2000 pds, recent upgrade to alltrax controller, so answer may be something in the combination. I think February 2010 battery date.

Charged batteries tues night, cart rode on trailer and sat until this morning, got up this morning and rode to the woods, volt meter showing very low batteries, plugged in and charger turned back off. I do not have dvm here in the woods, but it was 23 last night and was still mid 20's this morning when I took it out. I don't know long term health of the batteries, nor have I really dealt with electric cart through the winter, so do the batteries freeze if too much water, causing something like this? I know cold affects them, but also see folks using them as snow plows. Am I seeing the end of the batteries, or do I just need to add acid/electrolytes/???? Is it too much water? I honestly have taken their health for granted, but may need to do some better care of them. Any ideas? At least that I can do in the woods? Do have access to a a small auto parts store about 30 min away. Thanks

[JohnnieB]

At 100% SoC, they won't freeze before -90°F.
At 50% SoC they won't freeze before -5°F.

Battery storage capacity decreases by about 10% for every 15°F below 77°F, so at 20°F your batteries only have about 2/3 their rated capacity, and the storage capacity also decreases as the batteries age.

Giving your cart a 30 minute refresher charge before taking it out, will help.

Your batteries are going on 4 years old, so they very well may be at or near the end of their useful life. It depends on how well they were maintained before you had the cart as well as how well you've maintained them.

Also, if the were put in a stock cart and the cart has since been upgraded, they may be too small for the application. A cart with 500A controller and 23" tires draws a lot of amps.

[sleepyluke]

That was about my theory, and it for sure makes sense. By the way, could it be possible they are original 13 year old batteries and it still be running? I found Trojans site again and realized they do not put decade info on the batteries. I think I have for sure gotten myself into new batteries before I wanted, but at this point I may be done for a while if I buy them.

I will also put it on the charger every time it moves, so maybe I can get it back home.

I guess I now need to go to Johnnie's battery chart!

Thanks for good info as usual.

Originally Posted by sleepyluke

. By the way, could it be possible they are original 13 year old batteries and it still be running?

they would be the only ones i've heard of going over 8 years

[yurtle]

My Exides went 9 years to the month.

EDIT: I'll bet I coulda gotten another year out of them, but I wanted to do the upgrade in my sig.

[JohnnieB]

Originally Posted by sleepyluke

...............
1. I think I have for sure gotten myself into new batteries before I wanted, but at this point I may be done for a while if I buy them.

2. I will also put it on the charger every time it moves, so maybe I can get it back home.

3. I guess I now need to go to Johnnie's battery chart!

1. You might be able to extend their useful life a bit longer by charging the living daylights out of them.

First, if you can lay your hands on a 6V charger, give the batteries whose At-Rest voltage is less than the rest additional charge time. An alternate method would be a 12V charger and charging the worst two in series, but you may have to do some battery shuffling to pair two batteries with similar At-Rest voltages together.

Second, once you have all the At-Rest voltages as close together as you can get them, repeatedly initiate new charge cycles on them with your regular battery pack charger when they are "Fully" charged. In other words, when you see that the charger has shut off automatically, unplug it from the cart and then plug it back in.

Why this works, gets a wee bit technical, but you can sometimes recover some of the storage capacity lost due to aging simply by recharging charged batteries. I regained about 10% with a set of T-105s over a matter a few weeks of charging them two or three and some times four times a day with an ordinary, unmodified, PW II charger. YMMV.

2. Another thing that will help in colder weather is keeping the cart in the warmest spot possible when not in use. For instance unheated shed gains some heat when the sun shines on it. Just parking the cart where the sun shines on it will help.

The batteries have a huge thermal mass, so they hold heat for several hours after they are exposed to a colder temperature and it is the temperature of the plates and electrolyte that determine storage capacity.

3. The trick is to get the highest AH you can afford at the best price you can find locally.

[remac]

There's gotta be a joke here about parking the cart where the sun don't shine.