Flooded battery float and equalization

I have a 100AH x 4, i.e. 48v battery bank, flooded deep cycle batteries, on a solar inverter.

- The batteries are for backup in case of power failure so they're RARELY discharged.
- I have set a float of 52.8v
- Bulk charge at 57v.
- Room temperature goes as high as 44c.

Now I have read that if a battery isn't used / discharged at all, and is left on a float charge, it can be damaged? Is this true?

Should I do a monthly or twice monthly equalization to keep it healthy?

Are those voltages consistent with battery manufacturer recommendations?

Are the 4 12V batteries always at the same voltage, especially when system is at bulk voltage?

Do you have temperature compensated charging consistent with the battery manufacturer's recommendations applied? 44°C is a fantastic way to kill batteries. Highly likely that you will get less than 50% of the claimed life simply having them in an environment.

You NEVER equalize batteries at elevated temperatures. You will damage them.

logslogs said:

I have a 100AH x 4, i.e. 48v battery bank on a solar inverter.

- The batteries are for backup in case of power failure so they're RARELY discharged.
- I have set a float of 52.8v
- Bulk charge at 57v.
- Room temperature goes as high as 44c.

Now I have read that if a battery isn't used / discharged at all, and is left on a float charge, it can be damaged? Is this true?

Should I do a monthly or twice monthly equalization to keep it healthy?

Click to expand...

What batteries do you have make/model?

I wouldn't "equalize" unless you need to. Stored batteries don't need to equalize on a regular schedule, just a top off charge monthly would suffice. Generally speaking, batteries should be stored in a cool environment- None will recommend 44C. Check water levels and S.G. often!

seneysolar said:

What batteries do you have make/model?

Click to expand...

These are Flooded deep cycle batteries. It's AGS, a local brand in my country.

My main concern is, will there be sulfation due to just staying on float charge for so long?

If not equalizing, should I just discharge them to maybe 50% once a month and recharge to the normal bulk charge of 57v? That would be enough to prevent sulfation?

logslogs said:

These are Flooded deep cycle batteries. It's AGS, a local brand in my country.

My main concern is, will there be sulfation due to just staying on float charge for so long?

If not equalizing, should I just discharge them to maybe 50% once a month and recharge to the normal bulk charge of 57v? That would be enough to prevent sulfation?

Click to expand...

No, they don't need to be discharged. They will actually self-discharge slowly on their own (this is normal). That is why a monthly top off charge is normally recommended.

Float charge is supposed to be optimum to reduce sulfation rate. If I were to GUESS, it will be closer to 52.0. The manufacturer should publish their recommended float charge though.

Batteries that spend their whole life in float will eventually overcharge. I keep batteries in stock for my business. I have the trickle charger on a landscape timer to come on for a couple hours 1 day a week. The rest of the time they sit with nothing. This is simply to keep them from self discharging.

logslogs said:

These are Flooded deep cycle batteries. It's AGS, a local brand in my country.

My main concern is, will there be sulfation due to just staying on float charge for so long?

Click to expand...

I guess I didn't state it clearly enough...

This should be your LAST concern AFTER you have answered "YES!" to all three of my questions

Answering "No" to any of the questions means you are destroying your batteries MUCH faster than the to floating/equalize concern.