Keeping my stored SLA batteries charged

Footie

Esteemed Pedelecer
Jun 16, 2007
549
10
Cornwall. PL27
Having replaced my 3 SLA batteries with a LiFePo4 battery I don't want my old SLA batteries to die on me.
As they are now separated, I can't use the original charger 36 volt :eek:
I have a small 12 volt trickle charger (Lidl special) and I am connecting each battery up for about an hour each month - no lights to tell me it's charged, so it's a bit of guess work.
Will this keep my batteries good?
I intend to use them to create a push trailer but it will be a while before that project is up and running.
Is there anything else I should be doing to keep my SLA batteries good.
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PS: Ordered the trailer yesterday £79.99 including delivery
Cycle cargo utility trailers, box carriers, Bike care, Mission, Avenir Mule, Eco trailer, Spokey Joe
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flecc

Member
Oct 25, 2006
52,761
30,348
All lead acid batteries need regular "cycling" of the charge to stay in good condition, leaving them standing can lead to sulphating which impairs the current delivery.

Easiest way is to connect a car headlamp bulb on each one for 1 hour each month, typically draining 4 to 4.5 Ah, and then reconnect the trickle charger to top back up again. Overcharging on a trickle charger isn't usually a problem, but once they reach over 13 volts each (when measured off the charger) you can cut the charge to make sure.
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sparky5

Finding my (electric) wheels
Apr 5, 2008
23
0
SLA Batterys

All lead acid batteries need regular "cycling" of the charge to stay in good condition, leaving them standing can lead to sulphating which impairs the current delivery.

Easiest way is to connect a car headlamp bulb on each one for 1 hour each month, typically draining 4 to 4.5 Ah, and then reconnect the trickle charger to top back up again. Overcharging on a trickle charger isn't usually a problem, but once they reach over 13 volts each (when measured off the charger) you can cut the charge to make sure.
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I have had some years of experence with sealed lead acid batterys mainly used on UPS systems and of course Flecc is absolutly spot on.
The batterys need to be perodicaly "cycled".
That is run down and re-charged this will help to prevent sulphating and loss of capacity.
In a UPS the batterys are constantly float charged and it has been found that if not periodicaly Cycled will refuse to supply the required output when needed, so it is deemed good practice to run the ups to "cut off" at least once a year.

so therefore if kept for a long time "not used" the effects are the same and the batterys will eventualy "die" of old age even if not ever called upon to support the load.

As with all chemical power sources the reactions will continue within the cells and there is nothing we can do to stop it, all such things have a finite life and the best we can do is to slow the deterioration of the battery, by using best possible management ie cycling on a regular basis.
HTH
Cheers, Mark.
 
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flecc

Member
Oct 25, 2006
52,761
30,348
As with all chemical power sources the reactions will continue within the cells and there is nothing we can do to stop it, all such things have a finite life and the best we can do is to slow the deterioration of the battery, by using best possible management ie cycling on a regular basis.
HTH
Cheers, Mark.
That was the big benefit of the old car batteries which had to be topped up, the ability to drain out the electrolyte, rinse, and suspend the aging. Some were stored throughout World War II like that. SLA is like all progress, a couple of steps forward and one step back. :rolleyes:
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Footie

Esteemed Pedelecer
Jun 16, 2007
549
10
Cornwall. PL27
flecc and sparky5.
Thankyou for the information - I've learnt something useful today ;)
With the imminent arrival of my new trailer (and the close proximity of the local golf course - 2 miles) it may not be long before the batteries are back in use :D
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