Looking after an SLA battery

[Harry Bloomfield]

Mobility scooter batteries in particular, plus leisure batteries...

What is the best way to get the longest working life out of them?

I have always been of the opinion, to use them, use as little of the capacity as possible then fully recharge them, and keep them fully charged. Every few weeks, if they have not been used, ensure they get a boost to a full charge. Leaving them partially charged, wrecks them. My batteries do last an awful long time..

Some say, even some claiming to be supposed experts, say use them until near flat, only then bother to recharge.

 

[Old Salt]

I think it may align to the 80 / 20 rule. Charge to 80% if being left unused for a while, discharge to 20% before recharge.

 

[Harry Bloomfield]

I think it may align to the 80 / 20 rule. Charge to 80% if being left unused for a while, discharge to 20% before recharge.

No, that is the 'rule' for lithium cells, as used in your laptop, and phone - some devices include that 80% limiter. For SLA they suggest try to limit discharge, to 50%.

 

[ericmark]

The problem is time and over charging and under charging. If overcharged they lose water, if left even at 95% the sulphur starts to harden on the plates, and all cells will not be identical so you do every so often need a small amount of over charging to equalise the plates, but not for very long, or it will lose too much water.

So it is all down to the charger, the one I use reduces the charge in stages, and stops at 14.4 volts, the battery is then allowed to self discharge until 12.8 volts at which point it starts to charge again.

So a battery discharged to say 25% and with a mobility scooter with a range of 25 miles, looking at an 18-mile run, at 4 MPH that's 4.5 hours, and in real life that means multi-use with no charging between for example when on holiday, so it has been left discharged for a week or more, so it will cycle between 12.8 and 14.4 volts many times before fully recharged.

In the main we will not travel anywhere near 18 miles, and we will recharge within an hour of returning home, and during colvid I noted my wife Jag left on charge for many weeks, would actually charge every day at 12:30 pm for around ½ hour at 0.2 amps, so since same time every day I assume that was the time data is sent to Jaguar?

My problem is the scooter is a big lump, and the scooters own battery charger only works with the batteries the scooter. So I want to store scooter in a shed, so I have unscrewed the two batteries, and I use a cheap Lidi charger to keep them topped up. This also means if one fails, I don't lose both, which had happened, one cell went short circuit so other 11 cells were overcharged.

 

[Harry Bloomfield]

My problem is the scooter is a big lump, and the scooters own battery charger only works with the batteries the scooter. So I want to store scooter in a shed, so I have unscrewed the two batteries, and I use a cheap Lidi charger to keep them topped up. This also means if one fails, I don't lose both, which had happened, one cell went short circuit so other 11 cells were overcharged.

I only usually put mine on charge, after use. Basically I park it, straight in my workshop, which has the charger mounted on the wall, ready to plug straight in, before I even get off it. It then stays on charge, until the charger shows a green LED, then it is unplugged, after until next time it has been used, or given a boost if it has been unused for a good while. It seems to work, the 5x batteries, are good as new 12 months on.

What I'm seeing is lots of people complaining their batteries only last a few months, and people, even manufacturers, claiming that they should be run to near flat, before recharged.