Charging SLA's

[NightShift]

Charging SLA\'s

I've found it before, but I cant seem to find on the web, the formula on how to calculate charging time at a certain rate (mAh) for SLA batteries. For example, I want to know how long to charge a 12v 5AH battery for at a certain rate...say 100ma or whatever rate I choose....or a 6v 4AH at whatever rate. Does anyone know how to calculate this? Thanks

 

[Chris M.]

Re: Charging SLA\'s

I can`t offer a definate answer at this moment but I do believe that SLAs are best charged at a constant voltage (usually ~2.2 volts per cell for standby use).

Our fire alarms charge at about 27.3v (2x 12v cells in series) and are constantly trickle charging, it`s no more than a few mA but will initially suck 500mA+ when drained (eg, after a power failure), and are fully charged overnight.

Somewhere I have Yuasa`s specs on maximum charging voltages/currents for their sealed cells in both standby and cyclic uses, if I get the chance later I`ll dig round and see if I can find them.

 

[NightShift]

Re: Charging SLA\'s

Ok, i finally found the paper that contained the battery charging info. This look valid?

http://www.bigtoesolutions.com/battguide.htm