Rechargeable Gel cell substitution

[Demon]

I'd like to save from scrap 3 flashlights that use a SD415 4V 1.5Ah battery.

These seem extinct, any suggestions on an equivalent battery?

Mine is by San Ding.



Robert

[richard]

if you can get the top off the battery could you scoop out the guts and stick a couple of lipo batteries in there , they are nomimaly 3.6v but read 4v + when fully charged

[Demon]

They don't really have to fit back in the old battery case, I can tie-wrap them together and stuff them in the handle.

I just have little to no battery experience and wasn't sure what types I can and cannot use in a gell cell application.

Robert

[Archangel]

Hi Robert, have you checked Mouser? http://www.mouser.com/Power/Batterie...5gbk?P=1z0wd7y
Might have something useful.

[Charlie]

The gel cells are basically lead acid car batteries (in this case with 2 cells instead of the usual 6). In this application you can use pretty much anything that can supply lots of current for a long time.

The tricky bit will be the charger. If the flashlights are the ones with a built in charger, and you want to use that charger, then you should stick to gel cells. If you are willing to charge them externally, you can use pretty much anything.

Attempting to charge LiPo or even Nimh with a lead acid charger is likely to require a fire extinguisher, or even an ambulance.

[EarlyBird2]

Check this site
http://www.atbatt.com/batteries/agm-...?voltage2=3986

looks like your picture.

4v 1.5Ah is very small for lead acid!

[Demon]

...
The tricky bit will be the charger. If the flashlights are the ones with a built in charger, and you want to use that charger, then you should stick to gel cells. If you are willing to charge them externally, you can use pretty much anything.

Attempting to charge LiPo or even Nimh with a lead acid charger is likely to require a fire extinguisher, or even an ambulance.

Yup, the flashlight has a builtin charger circuit, I'd like to use that if possible.

It's an LED flashlight, I find it very practical for playing pretend-mechanic.

And that's why I'm asking here. Don't want to burn down my new garage.

Robert

[Demon]

Check this site
http://www.atbatt.com/batteries/agm-...?voltage2=3986

looks like your picture.

4v 1.5Ah is very small for lead acid!

Darn, just a tad too wide.

This site didn't come up in my googling. I hate it that location plays such a huge part in search results.

[Demon]

Hi Robert, have you checked Mouser? http://www.mouser.com/Power/Batterie...5gbk?P=1z0wd7y
Might have something useful.

Hadn't thought of them, just a tad too big.

I hate our disposable retail industry, it costs more to buy a battery than a complete unit on special.

I think these had cost $9.99 years ago.

Robert

[Demon]

1.15" x 1.35" x 2.73"
29mm x 34mm x 69mm

I don't have a lot of room to work with.

I suppose I can't even use old NiCD instead of SLA.

Robert

[Charlie]

It's hard to get to the correct voltage with NiCD or NimH - you end up with 3.6 or 4.8. If the charger is well designed it should be putting out 4.4, and constant voltage, where the NiCD or nimH want constant current.
When you eventually find the right replacement battery, you will likely find it cheaper to buy another flashlight than a replacement battery - at least that was my experience.
Comes of buying things on sale at CTC, I guess.

[Demon]

I know and it sucks. I like these first-gen LED worklights and feel bad throwing away a perfectly good device.

Robert