Golf Cart Battery Lifespan Question

[marsofold]

Bought my six Johnson Controls golf cart batteries at Sam's Club three years ago. Other than a handful of discharges to the 75% SOC just to test them, they are almost virgin. Verified again today that they'll still run my 3/4HP well pump through my 6-Kilowatt MSW inverter & a GE-1.5Kw 120v:240v Transformer. How much more lifespan should I reasonably expect to get out of them?

[BB.]

From the Deep Cycle Battery FAQ:

Lifespan of Batteries

The lifespan of a deep cycle battery will vary considerably with how it is used, how it is maintained and charged, temperature, and other factors. In extreme cases, it can vary to extremes - we have seen L-16's killed in less than a year by severe overcharging and water loss, and we have a large set of surplus telephone batteries that sees only occasional (10-15 times per year) heavy service that were just replace after 35+ years. We have seen gelled cells destroyed in one day when overcharged with a large automotive charger. We have seen golf cart batteries destroyed without ever being used in less than a year because they were left sitting in a hot garage or warehouse without being charged. Even the so-called "dry charged" (where you add acid when you need them) have a shelf life of 18 months at most. (They are not totally dry - they are actually filled with acid, the plates formed and charged, then the acid is dumped out).
These are some typical (minimum - maximum) typical expectations for batteries if used in deep cycle service. There are so many variables, such as depth of discharge, maintenance, temperature, how often and how deep cycled, etc. that it is almost impossible to give a fixed number.

• Starting: 3-12 months
• Marine: 1-6 years
• Golf cart: 2-7 years
• AGM deep cycle: 4-8 years
• Gelled deep cycle: 2-5 years
• Deep cycle (L-16 type etc): 4-8 years
• Rolls-Surrette premium deep cycle: 7-15 years
• Industrial deep cycle (Crown and Rolls 4KS series): 10-20+ years.
• Telephone (float): 2-20 years. These are usually special purpose "float service", but often appear on the surplus market as "deep cycle". They can vary considerably, depending on age, usage, care, and type.
• NiFe (alkaline): 5-35 years
• NiCad: 1-20 years

So much depends on how well you treat them (and mfg. choices/quality/age/etc.)--It is a gamble. Treat them nice, and keep money in the bank account in case "something bad" happens.

-Bill

[icarus]

I'm on year 12 (maybe 13)on a set that was used daily for 9 with 20% max discharge. Now they are on a small array, with very limited loads,, a couple of lights and a fridge igniter a few months a year.

My "main set" is in year 5 and still tests fine. I budgeted for 5, expect to get 8 and hope to get 10 years.

Tony

[marsofold]

I'm on year 12 (maybe 13)on a set that was used daily for 9 with 20% max discharge. Tony

Thanks. I feel a bit better about mine now. I was hoping to avoid buying a forklift battery or two. The Crown forklift battery I was considering weighs 700 Lbs and I'm not sure that I could slide it down my cellar steps without the steps buckling. But there's no other way down there. Anyone have any experience with such things?

[Photowhit]

My Sam's Club 'Energizer' 6Volt golf cart batteries lasted 5 years, being abused for the last 4 summers, regularly run down to 50% capacity running an Air conditioner. I only expected and would only expect them to last 3-5 years in use after 5 years I'd think bonus years(I really thought after 3 years in my situation) 3 strings of 2 might make it a bit harder to maintain them. I had 1 string of 4 for most of their life.

I switched to a 1100lb fork lift battery after and it took some time and good levers to move it 12 feet into my outside battery box.

[vtmaps]

Most battery manufacturers define a dead battery as one with only 80% of its rated capacity. In a typical RE application a dead battery may live for a few more years.

I'm still on my first set of batteries (almost 3 years). Question for those who've had a few sets of batteries: When do you decide that your batteries are dead and need replacement?

--vtMaps

[Cariboocoot]

Most battery manufacturers define a dead battery as one with only 80% of its rated capacity. In a typical RE application a dead battery may live for a few more years.

I'm still on my first set of batteries (almost 3 years). Question for those who've had a few sets of batteries: When do you decide that your batteries are dead and need replacement?

--vtMaps

When they won't do the job anymore.
This usually means they will not get from one charge period to the next under typical conditions (i.e. you have to start the gen at night because they've gone flat, you have to start it in the morning because they won't last 'til the sun does its thing, et cetera).

[2manytoyz]

My oldest set is 5 1/2 years old. They're getting tired according to the hydrometer.

Old batteries:



The newer batteries:



A close-up of the meter:



So the older batts are ~ 1.25. Roughly 85% capacity remaining. The new ones are at 100%.

These batteries live in a hot garage in FL, and have never been below 50%. I expected to get 5 years of useable life out of them. Not a bad deal for less than $80 batteries. I'll continue to monitor them. They might get replaced towards the end of the year. When these reach about 75-80%, I'll get another set from Sam's Club.

Important to note the older batteries need watering more frequently than the newer ones.

[CDN_VT]

I can't post a like / point / whatever Robert , But i do enjoy your posts, toyz .
Great info Sir!

VT

[Dill]

Robert, where did you get your hydrometer?