Forklift/Golf Cart Battery Combination

[freejuice]

Hi Folks,
I have 8  (6v) golf cart batteries wired in series for 48 volts. ( 225 Ah)
However I was given a forklift battery which is 24 volts (which I thought had crapped out... but when I put the volt meter  across the terminals it gave me 22.5 volts....It has been a while since it has been charged so I'm thinking all it needs is a good charge and the fluid levels checked... then taken from there....
 Well this beast is made up of 2v cells; weighs in at 1500 lbs and has a 750 amp hour capacity.

So as my obvious question unfolds here...I've got to ask can I mix and match these batteries.....golf carts rewired for a 24 volt leg and the forklift battery for the other 24 volt leg, for 48 volts.
 Or is this "bad battery juju" to mix and match.....I'm far from a battery guru so I figure I would ask the pros.
Since this battery was absolutely free...I would really like to use it.
Thanks,
 Gavin

[Madscientist267]

Wouldnt do it.

Mixing in series can get you into trouble.

You're better off (if everything is conducive) to swap over to 24V and:

Put 2 banks of 4 golf cart in series, in parallel with each other, and then in parallel with the forklift battery.

If you mix them, you can cause anything from massive imbalance to cell reversal.

Wouldn't do it if it was me.

FWIW

Steve
 

[fabricator]

The problem you'r gonna have if you try to use the six volts and the two volts is charge imbalance, the lowest capacity batteries are gonna limit the entire bank, first thing I'd try would be to try to equalize that hilo battery, boil it for about three hours to see if the cells get anywhere near equalized.

[freejuice]

so I probably have a 1500 lb fishing weight?

I really dont want to screw up my golf cart batteries.

Call me stooooopid, but isnt  golf carts a string of 2volt batteries for 6v too? Obviously I'm not seeing the same things you folks are seeing, probably because I dont know squat about the dynamics of batteries

Fab, If I can boil the forklift battery to equalize it and I get a steady 24-26 volt reading...what then? Safe to string up, or more potential bad juju?

 Sorry guys I'm trying earnestly not to ask dumb questions here, but the realm of battery interactions is a "corn-icopia"of "corn-fusion"

So it remains a potential train wreck if I get the forklift battery to a good state of charge at say 24 volts, and use this series string for 24 volts and then rearrange the 8 golf cart batteries for series- parallel for 24 volts, then series the two 24 volt strings together for 48 volts?


-corn-fused

[TomW]

juice;

The main issue is series strings of unequal capacity cells.

You will never get them all equally charged. The low capacity cells will be cooking while the high capacity ones will be undercharged.

I have 2 unequal capacity banks in parallel and while it is not ideal I don't care.
.
Most lead acid batteries are 2 volt cells. Golf cart, automotive included. They just package them in one case. Big dog forklift batteries are series strings of large individual 2 volt cells.

If that makes sense?

And, of course, if I understand your question.

Tom

[freejuice]

Tom,
 Ok it has sunk in; it simply is the individual battery carrying capacity.
It makes perfect sense now, while charging; one smaller battery would be boiling away while another never reaches a full charge.... DOH... it makes perfect sense now....

 Heck, I was thinking the amps and voltage would share among the batteries until they reached a common amp load and voltage....or in another way, equilibrium.
 Ahhh, but by doing so I would have overloaded the smaller amp carrying capacity of the golf cart batteries and probably never reached a full charge on the monster forklift battery,

As the old saying goes I would have had a "Blivet"... I would have been trying to shove 10 lbs of poop into a 2 lb bag.

[fabricator]

Now ya got it, string some little tea cups and mason jars and five gallon buckets together with a hose, dump water in the hose and what happens? Not the best analogy but you get the idea.

[watermanhfl]

Freejuice,
2 thoughts.  I have the big brother 48 volt Baker truck battery that is 3,100 lbs and I love it still 4 year later.
After you confirm battery is good by equalizing, letting it sit for a day and measuring Specific Gravity, then get another similar one.  Many have said these truck batteries last a life time in the easy life of an RE system vs daily fork lift drain.  Assumes you do not drain too heavy too often.  Mine seems to love the 10' mill trickle charge with occasional boiling during a storm.  My battery guy says you can usually bring these back from the almost dead, as they are built so robust.  With 20+ volts you should be ok and in a pinch you can swap out individualized cells, though not easy.
But if the big guy has given in or you decide to stay with the small stuff, the battery has significant value with the price of lead.  Should be worth several hundred+ if sold to right place.
Ant

[Madscientist267]

Nice setup Waterman -

I need to build me a dog house for my batteries too... too many in the house now for me to be comfortable (even though I ventilate regularly)...

Steve

[freejuice]

Hi Waterman,
Nice setup!
I dont really want to scrap the battery out, it appears to have so much potential while its sitting at 22.5 volts with no charge!
 I could keep it charged, excercise it a bit, with a cheap-o inverter, then hope another one comes along...but batteries like this...for FREE, only happen once every blue moon.
However, another one would be the way to go, If I could find one used but in good shape, it would only be a bit more than another string of eight golf cart batteries!

Now If I can figure out how to get this thing off the back of the ol' pickup.... a chain fall and some stout timbers