6 volt golf cart battery

[(unknown)]

I wired the batterys in series to get my 12v hooked them up to my solar and small wind gen and started using the power,after a week or so I realised the batterys were not reaching full charge 14v but would stop at 12.5 ,,I've had plenty of wind and sun to get the job done and I even ran them on a charger for a couple hours and 12.5 was all I could get. Does anyone have experience with these batterys? Is this max voltage for them? I thought about adding a third battery in series and charging the 3 to 15 volts but thought I should ask someone first.

[dave ames]

"I even ran them on a charger for a couple hours"

..it may take a few cycles to get those batteries used to working. i would leave the charger on for several DAYS and cycle them a bit more and see whats what. nix the third battery in series idea..we are asking for trouble. did you get some readings on each single six volt seperately? both the same or is one alot lower?

give em a few cycles and see if they come up.

just one guys thoughts.

[DanB]

What is the voltage of the battery bank when no charge is coming in?

what sort of wind turbine do you have?  How much current (amps) is it producing?

And the same question for your battery charger.  My guess, if you can't get voltage above 12.5 is that you have a pretty small wind turbine and a pretty small battery charger.

I would not go adding a 3rd battery...

[madlabs]

As noted above, charge them for a longer period. Does the charger ramp down in amps as it charges? Do you have access to a hydrometer to read the specific gravity of the cells? What temprature is the battery at? Cold can cause a low voltage reading. Do you have any way to equalize the batteries (charge at 15.5 volts)?

I'm living on a 10 battery bank of the same batteries and so far they are working ok for me, but it has only been about 6 months.

Jonathan

[ghurd]

Two thoughts.

First, my regular old 10A charger only puts in about 8A max in a flat battery.

As the battery voltage starts to climb, the charging amps drop off really fast.

By about 13V, I think it's down to about 1A.

Could be your charger is dropping down the amps sooner, and it will take a long time to get them up.

Second, is this a cheap meter?  Like the $3 HF meter?  They get flaky if the battery gets low.

Change the 9V battery to a good quality alkaline and test the voltage again.

Could test the meter by checking the battery voltage of a running car.  They tend to be a hair over 14V on the cars I checked.

G-

[175lt2]

My solar only puts out about 50 watts on a good day and my wind generator is only about 100 watts on an average day,,Yeah it's not much but the system usualy gets a few days between uses to recover. I had 2 used car batterys that would reach full charge fairly quickly but I didn't get enough run time out of them so I replaced them with these,they are much better but the low voltage is a concern. My meter is a quality one and everything checks out,My charger is a bit wimpy though. I guess I'm not putting enough amps to these larger batterys?  

I do intend to add several more solar panels and a second wind gen.

Thanks everybody for all the help

Matt

[wooferhound]

You say you have 220 AH batteries

if you have a 10 amp charger then it will take more than 22 hours to charge them fully.

[dave ames]

hey matt,

a follow up note here,

with your last post we see that with the low capacity automotive batteries we came up to charge quickly and had less "run time" which had less capacity and therefore had less to recharge.

we changed over to nicer batteries with more capacity meaning more charge time needed but find we have more "run time". our available charge has not changed but we may have changed our "run time" habbits?

we have seen folks use their inverter alarm/low voltage cutoff to determine their "run time" and the results are always the same..bad. say it ain't so.

these little systems are fun and you will get a feel for how yours behaves after a very short time and know just how much is going in and out. one of the best things i did early on was to get a trimetric 2020 monitor.

it's all good fun, even the having trouble part!

kind regards, dave kb1mzf

[Gary D]

 It would be wise to purchace a sp. gravity tester. They are better to find the real state of charge left in the batteries than just a meter.

 You most times will get a higher voltage in the batteries if a small charging source intermittently puts a surface charge there. It's cheaper to learn on a small bank in the beginning - learn good habits and record the readings. It won't take long till you know how much "run time" or power you can use and how long it takes to get back up to full charge...

  Just a thought  Gary D