Old Cart, Old Batteries. Want to (Re)Start Right

[BurlyWizard]

A few months ago, we bought a 1998 TXT from a neighbor (original newb thread here).

I knew the batteries needed replacing, as they were mismatched, and the cart only ran for 30 minutes or so at a time. The seller factored this into the price and gave us a break. Well to make matters worse, we didn't know how to properly maintain it, and didn't water the batteries at all for the first few weeks of driving it. However, we quickly learned proper maintenance and began watering with RO/DI water (0-2 TDS). The performance of the cart remained unchanged over this time.

It's all been status quo since then, until the bar-chart voltage meter began acting up. Now I know these aren't accurate, but it stopped functioning altogether, and now only flashes the "Low battery" flash, regardless of how long the cart has been charged. Despite what it reads, the cart still drives as it was actually charging. The cart came with this charger, which I know isn't the best, but it's what we have for now.

If you're still with me, thank you. I'm just trying to lay out all of the variables to see what must be changed to ensure this gets running & maintained properly when we invest in the new batteries.

So, the problem we've faced of late, is that over the last couple weeks, the life of the battery has significantly dropped. Like from 30 minutes to about 10, tops. Nothing else has changed in our maintenance or use of the cart, but it seems to have run to ground very abruptly.

Is this the typical "end of life" behavior of batteries? If not, did we do something to expedite this wear-out? Please help me make sure we find our blind spots so when we buy new batteries over the coming days, we don't self-inflict any repeat errors.

Thank you in advance! This forum has been so helpful so far.

[kernal]

Typical end of life scenario for batteries. New batteries will fix the battery meter problem also. It isn't resetting because the charger can't get the voltage high enough to reset the meter. Not a charger problem, the batteries are just wore out.
The majority opinion here is to replace all the batteries with a matched set using purpose built golf cart batteries. All from the same manufacturer and all the same capacity. For longer run time between charges and longer service life, get the most capacity your budget will allow. If you do this yourself put run/tow switch in tow if applicable before doing anything else and be sure to put all the wires back exactly where they were. Batteries are heavy, 60lbs or so each. A cheap battery lifter helps a lot.
After install, charge batteries completely before use. From now on charge them at the end of the day when finished using the cart. If not using the cart for awhile don't depend on the charger automatically refreshing the charge. Do not let the batteries stay in a partially discharged state very long. Lithium is different if you should go that route. $$$$

[BurlyWizard]

Thank you very much for that response. That's helpful and reassuring.

I have been just plugging in the charger and leaving it in all the time (even for weeks on end while we are not using the cart) as the charger is marketed as a trickle charger.

What is the typical recommended charging strategy in terms of length of charge and when to not charge?

[kernal]

Describe the charger you have. Make, model and any info we can use to identify it.

[BurlyWizard]

It looks identical to THIS.

Model: DLDZ-36VA
100-120VAC
Not sure of the make, but it very well may be that exact one linked above.

[kernal]

That charger only produces 5 amps. Not suitable for golf cart batteries. If you use this with new batteries it will ruin them also. You need a real golf cart charger that produces more amps with a modern algorithm. These are going to cost in the $250-350 range new. Cheaper used if you can find them. No way around it.
If you want to read about how to care for flooded batteries here is the Trojan battery company user guide: https://www.trojanbattery.com/tech-s...y-maintenance/
You can scroll to the section you're interested in. Flooded batteries by other companies are basically the same.
The bottom line is this: The batteries are the heart of the system in electric golf carts. They need batteries that are designed to take the abuse. This is different than the "starting" battery in your car. They need industrial strength chargers. Properly charged and maintained golf cart batteries will last 5-7 years average but this time can be longer or shorter depending on conditions and maintenance.

[Bama Brad]

If you are going to buy batteries and a charger, you should consider lithium. Drop ins come with chargers, digital meter and bms. More cash up front, but they should last 10-15 years and NO maintenance.
Here's a good thread... https://www.buggiesgonewild.com/showthread.php?t=173142