More battery fun

[Matt_H]

Well, there's been plenty of discussion lately on removing batteries, but what about replacing them? :-)

My A3000 needs its battery replaced, so my plan is to hook up an enclosed battery case with 2 AAA rechargable NiCd batteries. This way I can swap them out easily if I need to, and the Amiga should still charge them up.

Planning on doing the same on my A4000T, only using the "BATT" connector, and precharging the batteries elsewhere to compensate for the lack of a charging circuit. Or maybe I'll just use regular AAAs; haven't decided yet. Depends on what materials I've got lying around.

Trouble is that the rechargables will only output 2.4V when hooked up. Can the RTC handle that?

[odin]

Why not use 3 AAA rechargeables then? That'll make it exactly 3,6 volt and er....lots of Ah :-).

[TjLaZer]

Get the NiHm direct replacible ones from Red.  He sells them all the time.  They will not leak and if they did no damage to your Amiga.  I bought a few spares and did the mod on a few 4000's already.  You could also do the Lithium batt hack.  Did that as well, more work though.

[Matt_H]

@ odin

Because I stupidly didn't read the lower voltage rating on the rechargables until after I bought them :-)
And I only have a 2-slot battery case.

@ TjLaZer

Er... are you saying the NiMH batteries don't leak? I wish I'd known that earlier, could've saved a few bucks.

@ Red, if you're reading

I'll probably be contacting you shortly!

This project seems to be crashing before it gets on the runway. At least I can salvage the battery case for the 4000T.

[odin]

Who needs battery cases anyway, a soldering iron, some wires and duct tape are all you need ;-).

NiMH's do leak, as do NiCad's. It just takes long before they start leaking. The normal batteries in A4k's are NiMH's (At least in mine it was a NiMH, maybe NiCads have also been used?).

[QuikSanz]

@ Matt_H,

What ever battery you chose? Remote locate off board. That way, no problem Man.

Chris

[TjLaZer]

@odin

I am pretty sure that all the Varta batteries on the 2000/3000/4000 WERE NiCad only and NEVER NiMh.  If (NiMh) they do leak they will not damage the PCB.

@Matt

The Lithium hack works great, you install a diode to disable the charge circuit and use 3 Volt PC type coin type batteries.  See AmiNet.  Also see the images on here for a pic of such a hack done to a 2000.

[DanDude]

TjLaZer said:

Get the NiHm direct replacible....They will not leak and if they did no damage to your Amiga.

I've done some research and believe it or not, they can leak from failure, incorrect connection or stress.   :-(

BTW, nice avatar.  :-)

[orange]

What do you do if battery has leaked badly and PCB won't work? I've checked all connections/traces (and resoldered them) that were damaged by acid on A501, but Amiga 500 still doesn't see additional 512kB of RAM.

 :-(

[BoingBoss]

Hi Matt_H,

Trouble is that the rechargables will only output 2.4V when hooked up. Can the RTC handle that?

Try using three (3) AAA rechargable NiCd batteries.  The RTC needs at least 3.6 volts.  Each AAA rechargable NiCd battery puts out about 1.2 volts, so three of them should output 3.6 volts (just what the RTC needs).   :-D

[X-ray]

@ Matt_H

I recently took the battery out of my A4000T: had to use a screwdriver to prise the coin battery out from the connectors.
I got a 3.6v Maxell battery from Maplins, you know the one that has a lead for connection to 'Batt'. Was a little bit expensive: £8. Just plugged it in, used the supplied velcro and it now sits at the bottom of the case, away from the motherboard, in a recess near the internal speaker. That sucker can leak, blow up or do a little dance and I still won't be worried.

PM me if you want pics of the battery

[Acill]

 That sucker can leak, blow up or do a little dance and I still won't be worried.

Funny stuff. I dont know why, but that had me on the floor. Great way to start the day off. Thanks!  :lol:

[odin]

TjLaZer wrote:
@odin
I am pretty sure that all the Varta batteries on the 2000/3000/4000 WERE NiCad only and NEVER NiMh.  If (NiMh) they do leak they will not damage the PCB.

Really? That's good news, as mine was fitted with a NiMH accu :-):

[x56h34]

@odin:

Are you sure that this battery was originally supplied with your Amiga? Did you buy it new? If your Amiga was bought used, then it's for sure that someone replaced the old NiCd battery with this NiMh.

[TjLaZer]

@Odin,

Maybe in NON US countries they installed NiMh from the factory, but every 2000, 3000 or 4000 that I have seen here in the good 'ol USA has had a leaky Varta NiCad installed, and subsiquently leaked almost always causing damage (in 4000s for sure, a 2000 survived with extensive leakage.)

EDIT. Oh ok I was right then, no NiMh from West Chester or abroad.