Forklift battery help and system ideas please

Re: Forklift battery help and system ideas please

We only have one bank, but that one is a set of forklift batteries. Ours are an 1875 amp hr. set that have been in use for a bit over 20 years, running our house [purchased new]. We recharge them from PV only, no generator. Our array is now around 2000 w. but was only 900 w. for the first 14 yr. of the battery life [I was ignorant that this would be considered too small, but we've been ok all along]. We are up at 8500 ft MSL, so perhaps we have gotten by with a bit smaller array that others could, I don't know. But we do not use anything but PV to provide electricity and battery charging.

I sized our bank to have a maximum of somewhere around 20% discharge before recharging. Or that was my estimate way back when. Twenty yr. later, we do use more electricity but almost all of the additional is used during sunlight hours.

These forklift batteries can really last a long time.

Re: Forklift battery help and system ideas please

Maintenance has been nothing more than adding distilled water, which I check about twice a year as experience with these batteries has shown more frequent checks are not necessary. I have never had to add more than a cup or two of water to any one cell.

I didn't equalize for many years. I didn't know about it. I thought I did, but later found out [partly through reading forums such as this one and some books and articles such as found in Home Power magazine and etc.] that what I was doing was just bringing up an overcharge situation for a couple hours, maybe once a year. Once I realized how much more was involved, I did equalize but only, again, about once a year.

Additionally, I did the usual cleaning up of the battery tops that one does with any lead acid battery.

I have been using HydroCaps since the batteries were new. That is likely why my water usage has been so minimal. A gallon of distilled lasts me over a year.

There was one incident where the old controller I had then malfunctioned. The mechanical shut-off to the batteries, like the solenoids used in cars for the starter, locked in the closed position. I never figured out why. I had to open the contacts and clean them up with emery paper, then they never locked shut again. However, while they were locked up, I didn't realize it for a while and the batteries were above the recommended voltage for some time. I don't know how long. I discovered the problem when I kept smelling hot plastic, which turned out to be the HydroCaps melting. They were all destroyed, the caps, and had to be replaced along with more water than usual. However, I could detect no damage to the batteries, amazingly enough. But it was scary and I ultimately installed some new Outback charge controllers.

When I purchased the batteries, the dealer [who usually sells to warehouse and etc. for forklift use] told me that the usual habit of users was to run the battery banks virtually dead during a work shift and then stick them on a powerful charger which would go all night, or another 8 hours. So, take the batteries down low and rapidly bring them back up. They use 14.2 volts as a final level, he said. The average lifespan of the batteries, used this way, according to his experience of selling the users new sets, was about 6 to 7 years. At least, that's what he told me. He was afraid I would be unhappy with the batteries used in a PV system since I would not be sticking them on a high-powered rapid charge system.

But I have been very pleased, obviously. I did not equalize them properly for fifteen years and had the one incident with the controller and still the batteries have lasted and lasted and are still working. They are not as good as new, of course, but they are still working. They are installed inside our house so they are not subject to much of a temperature swing and are never cold or hot. Nor do they suffer any mechanical wear from being on a moving vehicle. So I am quite happy with forklift batteries....

I haven't done any price comparisons for forklift batteries and dedicated, designed-for-solar batteries in some years, but back when I was buying mine, the forklift batteries were less pricey than the solar ones. Don't know whether that is still the case. Plus, I could get them locally and not have to truck in from somewhere far away. However, the forklift batteries are so heavy and difficult to move around, one must consider that when deciding to go with them. My six cells each weigh 330 pounds and they are brutal to move.

Re: Forklift battery help and system ideas please

Hi Bill


Problem is that you don't want to take weeks to recharge a lead acid battery bank... If it is below ~75% state of charge, the cells are starting to sulphate (lead sulphate crystallizing within hours)--and once the crystals form, that material is never available for recharging again (battery looses capacity).

Question...... Will an Equalization reverse sulphation ?

Regards Peter