How Can I Charge this Battery ?

[mmartell]

I've never much understood this so I'm sure this will be useful to me

I have a battery from a solar lamp which I think is lead acid but I can't be sure (pic below). I've measured the output of the solar cell and it's just under five volts.

What math is used to determine charge times for a battery ?

[budm]

Re: How Can I Charge this Battery ?

Looks like the 6AH may be hard to get:

http://www.longwaybattery.com/en/new...wsTypeName=FAQ

http://www.longwaybattery.com/en/pro...me=GB%20Series

[mmartell]

Re: How Can I Charge this Battery ?

This battery was stored for several years before the lamp itself went in service so I think it may no longer be good but I want to attempt to charge it externally before I move on.

So how do I charge this up ? Can I use a walwart charger at 4.5v and how long would I leave it on ? If it's based on the mA of the charger what is the math to figure this stuff out ? Thanks

[stj]

Re: How Can I Charge this Battery ?

the datasheet should give the charging details.
if not, get a datasheet for the equiv from yausa

[joshnz]

Re: How Can I Charge this Battery ?

Give it 5 volts and limit the current to less than 1 amp

[joshnz]

Re: How Can I Charge this Battery ?

What math is used to determine charge times for a battery ?

Charge current divided by the capacity plus 20 percent.

so 6AH +20% / 500ma = 14.4 hours

[mmartell]

Re: How Can I Charge this Battery ?

Thank you thank thank you ! I wasn't really sure how to phrase what I was looking for

So can a wall wart work to charge this battery or would that be a problem ?

[tom66]

Re: How Can I Charge this Battery ?

Ideally you should use a current-limited bench power supply. The typical wall wart isn't regulated or properly current limited.

[mmartell]

Re: How Can I Charge this Battery ?

I have an atx ps that needs recapping maybe I'll start there.

[eccerr0r]

Re: How Can I Charge this Battery ?

If you have a wall wart that dumps out the voltage you need (use a meter to make sure, use the voltages printed on the battery as a guide), you probably can just stick a resistor, perhaps a 50 ohm 1W or so (depends on what wart you're using) in series as current limiting and use that to charge. Make sure that you disconnect it before it starts getting warm to prevent overcharge.

Yes that battery does look like sealed lead acid (AGM) from voltage and current capacity, but likely it's fairly sulfated by now. If it doesn't show any voltage across the terminals it's probably sulfated and a lost cause. Some people had luck with desulfators but most of my dead SLAs have other issues that the desulfator circuit do not help with...