Replacing battery with Lithium Ion

[djbase]

Gavilan wrote:
Is it that hard to make this hack?
I mean..im ZERO with soldering iron and all technical stuff, but with a diagram, or a simple picture of what/where do i have to solder...would it be possible even for a dummy like me to actually bring clock again to my Big Box Amigas?

Sebastian

http://www.amigaworld.de/workshops/lithium-knopfzellen/

[Gavilan]

@DJBase: excellent stuff my friend!!!!

Will do this tomorrow monday!!

Danke!!!

Sebastian

[Zac67]

Either I've got some visual problems or the aw.de folks got the diode reversed... :roll:

PS: I've contacted Matthias about this and he's corrected the sketch - thanks! (FF needed a shift-reload to load the graphics).

[Polymorph]

That auction is wrong, that is a lithium battery, not lithium ion.

I feel I should clarify lest someone tthink it is a good idea to use a rechargeable LiIon cell. It would be hazardous to install a rechargeable lithium ion battery and try to trickle charge it. LiIon cells are -very- picky about the rate of charge. They may simply die quickly, or burn and destroy your MB.

What he is -really- selling is a lithium button cell with a holder and a diode in series so current can only flow out, not in.

I "turbocharged" several Amigas by installing AAA battery holders on the case with long wires to the MB. I used three-battery holders with a silicon diode, 4.5V=0.7V=3.8V, close enough to the 3.6V NiCd cells it is meant for. And I put a sticker in there specifying -only- alkaline cells and gave the owners instructions to replace the batteries every two years. I also put a 470uF 6V capacitor in parallel with the batteries to give a few minutes to change the batteries.

I'd also converted some using carbon-layer capacitors, but longer initial charging time was a complication. Now I think I'd use polyacine capacitors. No leakage ever, much longer life, no problem with charging.

[motrucker]

There are various way to go about this. Cordless phone battery packs (many are the correct voltage - pick one that is) or - buy you own Button battery setup - Damn -  a regular holder is about $.20, the diode is about $.20 and the battery is about $.75 tops.
Don't get ripped off!

[terminator4]

http://www.amigaworld.de/hardware/lithium-batterie-modul/

By better, do you mean the pcb all parts are on?  if so then its not a big deal really.  Does it fit all amigas and where can one buy it?

[terminator4]

@Gavilian

that hack is easy.  Made one myself and it works great! :-)
aminet has the diagram.
http://aminet.net/docs/hard/LithBatt.lha
This has been done a long time ago on aminet...

[Polymorph]

motrucker wrote:
There are various way to go about this. Cordless phone battery packs (many are the correct voltage - pick one that is)

Make sure you get a -small- cordless phone battery pack. The
Amiga MB is only giving it a small trickle charge. I found that with 120mAhr 3.6V three cell NiCd packs, you'd better pre-charge them before connecting, and the stock trickle charge wasn't always enough to compensate for self-discharge.

That's why I just switched to AAA alkaline and a diode. DO NOT USE "HEAVY DUTY" OR ZINC BATTERIES. "Heavy duty" are just a fancier Zinc battery. Carbon-zinc batteries can sit in a drawer for a -long- time, but the first time they are used they start breaking down and will eventually leak all over.

Alkalines very rarely leak, and it doesn't spread.

[djbase]

terminator4 wrote:
http://www.amigaworld.de/hardware/lithium-batterie-modul/

By better, do you mean the pcb all parts are on?  if so then its not a big deal really.  Does it fit all amigas and where can one buy it?

Drop me a PM if want such a PCB version. And yes, it works on all amigas.

[Nostalgiac]

I couldn't be bothered ... so I just got a new barrel battery from Maplin.co.uk ... it should do me for enough years before it needs replacing again :/

Tom UK

[Damion]

On my A2000, I simply removed R803 (current-limiting resistor for the original NiCd) and replaced with a germanium diode (1N60)... then soldered the coin socket directly to the board and used a regular CR2032. Cheap, looks best IMHO, and nothing special to order. :-)

 

[Sandman]

-D- that is an AWESOME idea!  I would have never thought of that but will definitely do that on my next battery hack.... should put a sticky-note on the PCB crediting you with the idea too! :lol:

I usually just stick the diode under the battery holder which usually doesn't look to bad.

Would this work the same on a A3000?

[Damion]

@Sandman

I wouldn't have thought of it either, but I had the motherboard out to replace some caps, so it kind of caught my eye after staring at things for a few hours. :lol:

Would this work the same on a A3000?

I haven't looked at the A3000 yet, but I plan on doing that one next - probably it's just as easy. :-)

[Sandman]

-D-

Any reason for using the germanium 1N60 instead of just using a 1N914 switching diode?  I'm pretty electronics illiterate. :hammer:

[Damion]

Sandman wrote:
-D-

Any reason for using the germanium 1N60 instead of just using a 1N914 switching diode?  I'm pretty electronics illiterate. :hammer:

There's less voltage drop. The OKI RTC chip should stay alive with as little as 2v, so the small difference (as much as 0.5v) could matter when the battery is worn.