Is this lead acid battery behavior normal?

[Fingers]

I have four 6volt 225ah batteries wired in 12volt, bubbling away merrily, powered by a Lumiax max-mppt1010 10amp charge controller, and an Eco-worthy 100watt 18volt 5.55amp panel.

I have left them on charge without using them at all (I haven't got around to selling or using them).

Am I correct in thinking that although the green indicator light is on, they haven't fully charged? I mean, they aren't supposed to fizz when they are fully charged, are they?

 

[Zil]

It does sound like you are overcharging them. Not as bad as undercharging, but not all that good.

 

[time2roll]

What is the charging voltage? How long is that voltage held before float? What is the resting voltage when sitting disconnected for three days?
Could dip them with a hydrometer to verify the charge level.

 

[Wellbuilt]

Hmmm I don’t think you can really over charge a bank of 6 6v 225 ah battery’s with a 100 watt panel.
You should check the sg and see how they read

 

[Fingers]

What is the charging voltage? How long is that voltage held before float? What is the resting voltage when sitting disconnected for three days?
Could dip them with a hydrometer to verify the charge level.

the charger manual says float volt 13.7v, boost volt 14.5v, equal volt 14.8v load diconnect11.2v-11.8v, load reconnect volt 12.5v

 

[Fingers]

Hmmm I don’t think you can really over charge a bank of 6 6v 225 ah battery’s with a 100 watt panel.
You should check the sg and see how they read

That's what I thought, it's only a 10 amp charger and a 100 watt panel. I thought it should be no problem, but what do i know I'm new to all this.

 

[mikefitz]

Check you have wired the batteries correctly as a 12 volt bank. Confirm the voltage of the bank disconnected

If the batteries are not new to you, there may one or more faulty.

Mike

 

[Wellbuilt]

I bet you are only getting 70 watts out of 100 watt panel so 5 A
Your battery is 675 watts so 10% charg would be 67 watts of charging needed
The charge rat is really low

 

[Fingers]

Thank you all for your input.
All batteries are at the exact same state of charge, so that's good.
The problem was my inexperience, I didn't expect the batteries to bubble away like that.
The sun was out yesterday nice and bright and the bubbling lowered to a slight fizz; so I guess it was just charging, and then dropped to a float charge.
Phew, all good.

I wonder what a bigger solar panel and controller would have the batteries doing; roaring like a kettle on the hob?

 

[Wellbuilt]

I would not charge continuously , one week on 2 weeks off would be better .
My system sits for 3 weeks this time of year and when I turn it on my battery’s are still above full charge.
You should see more of a fizz then a bubble , watch your water use

 

[Red Squirrel]

Make sure the bulk and float charge setting is not too aggressive. ex: it does not put too much voltage and does not do it for too long. I had to lower the setting on my epeever unless I wanted my shed to turn into a hydrogen bomb. It was charging my 24v bank at like 29 volts for hours on end. Glad I caught that. Would have ruined about 1k of batteries in no time.

You should be able to leave them on indefinitly if the voltage is set right. This is what the telcos do. The batteries are setup in 48v and float at 54v. They don't really do any bulk or any of the other stages they just sit at float all the time. To me this is the simplest and safest way. Just need to do equalize once in a while. The telco ones usually do it after a long power outage.

Unfortunately not all chargers let you adjust any of these parameters though... hopefully yours does.

 

[gelmjw]

The bubbling is normal electrolysis; the breaking down of H2O into H and O gas. It is caused by high Voltage. The purpose is to stir the electrolyte. 15minutes is plenty of time. Done too long, it is a bad thing, leading to loss of water as the H and O gas escapes. H and O gas mixed are explosive. Electrolysis is also driven by higher temperature which is why some people in warmer climates use temperature compensating chargers.

 

[Fingers]

Unfortunately not all chargers let you adjust any of these parameters though... hopefully yours does.

No, unfortunately not. Just a cheap 10amp Lumiax Max-mppt1010.

I have a pwm 5amp, that may be kinder to the batteries.
I'm only storing them until I know what to use them or sell them off.

Thanks for your input.

 

[Fingers]

H and O gas mixed are explosive

Yes, I must get around to making a venting kit, and get rid of the gas out side.
To many jobs, not enough hours in the day