A question on battery longevity

[Xaugievike]

Another newb post.....sorry... This time it centers on battery longevity.

I've read many many many of the posts on batteries, and I grasp that they have a general useful life of what seems to be anywhere from 3-7 years based on use and care. Which brings me to my pack.

I have 6 Trojan T-105's all with the shipped date code of March 04 on them. Obviously that puts me north of 8 years old. I know that the batteries were new for the previous owner those many years ago. Based on my conversation with the previous owner I gather that this cart saw extremely limited use during the time he had it (obviously thats somewhat open to interpretation) as he mostly used it for a neighborhood cruiser....and he didnt cruise much. His knowledge of battery's (like mine) was somewhat limited, but he merely mentioned that the pack "seems to have no issues holding a charge," a conclusion he came to via the (stock) battery meter on the cart. My inspection of them showed the pack to be pretty clean, negligible corrosion, and that they were pretty close to full of water (I gave them a minor top-off after purchase - but no plates were really close to being exposed). I would gather from conversation that the PO never really deeply discharged the pack, and based on the water level in the pack never ran the water level low.

Here's what I see regarding a SOC for this aged pack. After 12 hours off the charger they will settle at and hold a pack voltage of 38.2 volts. I've confirmed that this reading holds for a minimum of 4 days. I recently let the pack sit for 10 days and i see a pack voltage of 38.1. As I understand, in terms of voltage I'm achieving, and holding a reasonably decent charge....????

I'm sort of wondering about charge duration (amp hours?). On a recent camping trip i used the cart just to putz around the campground. On flat ground, driving slowly with 3 adults on the cart for 30 minutes i registered no drop on the cart meter (unfortunately i did not bring my DVM on the trip to see where the pack was after this). At another campground on the same trip there were substantially more hills, one of which is very steep. with the same weight on the cart I would see my battery gauge drop to maybe 66-75% (ish) after only maybe 20 minutes of driving. It actually did much better when carrying just my weight, but would still drop at least 1 bar on the gauge in 20 minutes. I'm not really sure how accurate or useful that gauge is, but it's all i have to go by for now. I should say that the above mentioned camping usage will be 99% of what I use the cart for.....as of now.

So in terms of pack longevity, how is mine doing based on this brief and perhaps limited description? Obviously the batteries are aged and a new pack of them is at or near the top of my cart "christmas list." But i'm also sort of trying to prioritize that wish list and if the pack sounds at least "ok" for now I may move some other modifications a bit further up the food chain.

I appreciate any wisdom or guidance that you may have!

[jhnmflr]

You really need the dvm to check , or get a meter from Scotty , they are great . Also I wish my batteries would see 38.2 . I can't get above 37.4 after charge and they are only 3.5 years old .

[yurtle]

I'd definitely plan on getting new batteries in the near future. Mine lasted 9 years, but that's pretty rare. I agree with a digital meter, so you don't ever discharge them too deeply, which will kill them, and/or leave you walking home.

If your buggy had little usage, you're probably in better shape than I was with regards to bearings, brakes, and steering.

If you're planning on larger tires, that will probably finish the batteries off in short order.

[bigstik40]

And, as you probably already know - keep them charged. - RAY

[JohnnieB]

With light usage and conscientious care, those batteries might last another eight years.

Of course, the older batteries get, the more prone they are to sudden failures, like shorted cells.
But other than that, my guess that they are good to go for another couple of years and would plan accordingly.

Like others have alluded to, the trick to battery longevity is keeping them as fully charged as possible or practical.
I have a charger that goes into a float charge mode after the normal charge cycle and if I use my cart during the day, it goes back on charge that night.
Otherwise it just stays on float charge.

[Xaugievike]

thanks for the responses so far everyone.....As I type this I've had the batteries off the charger after a short neighborhood cruise last night....they've been off for 20 hours and are sitting at 38.4 at last look (20 or so minutes ago). I should add that one of the first things i bought for the cart was a battery minder desulfator (onboard version). Since adding that and doing some not-so-scientific monitoring it does seem as though my post and during charge voltages have crept upwards.

JohnnieB i again appreciate your knowledge....i think you just convinced me to first invest in a better charger that features a float mode for storage.

[jhnmflr]

Keep us informed as I might try this battery minder desulfator you speak of .It would be better than spending 6 and change on batteries ( and then a charger , casue ya know I'm going 48V )

[JohnnieB]

I believe an ounce of prevention is better than pound of cure.
Electronic desulfators seem to work pretty well when used as a preventive measure, but suffer from the same ills as the snake oil remedies after the plates has gotten sulfated.
I'm not sure is using a float charger and a electronic desulfator at the same time is better than using either alone, but I don't think it will hurt anything.