Amiga.org
Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: stanlong on December 10, 2008, 07:44:33 PM
-
Oh Mighty Ones
I must confess to the Amiga sickness cant resist any more.
Have just purchased an A2000 1988 with a dave hannie mobo
not dusty but corroded a bit battery etc even the floppy drive pins on tne mobo were in poor shape i cleaned them with alcahol
and all works fine
I will remove the battery
I see on the EAB some one has relocated the battery to the exterior ! is it worth it not original
-
I personally would never {bleep}ise anything having to do with the cosmetics(haven't seen this mod you speak of), but mounting the battery outside the case sounds a little extreme. When replaced with new, they've got an incredibly long life or you could simply do the mod with the diode and coin cell battery.
-
fellow caffien consumer
understand coin battery
Diode? could you give me more details
would apreciate diagram
with finer points explained
-
The hack is on aminet. Lithium battery hack.
-
stanlong wrote:
Oh Mighty Ones
That's us!
I will remove the battery
I see on the EAB some one has relocated the battery to the exterior ! is it worth it not original
Actually, that may be a bit mistitled. I did a similar thing to my A2K and A4K. What I did was to solder wires to where the battery (Varta 3.6V 60mAH NiCd) was mounted (after removing it), and soldered the other ends to a 2-pin header with .1" (2.54mm) centers. Once done, I just picked up a cordless telephone battery with the same voltage rating (3.6V, or 3-cell), and plugged it in, making sure to observe polarity. The "external" part was where I mounted the battery, as it can be Velcro©-ed or zip-tied just about anywhere.
On the A2K, the area just to the left above the keyboard/mouse ports on the front of the frame, but behind the cover (fascia?) is best. On the A4K, I was able to sandwich the pack over the CPU daughterboard behind the keylock switch.
Since the replacement battery packs typically have more capacity (300mAH or so), they'll take a bit longer to charge up, but hold the charge much longer. The charge rate is the same as the Varta, about 4-6mA, so as not to blow up the battery. This means something with a 300mAH rate will take about 50-75 hours to fully charge. To help out, I built a charging circuit on a breadboard to give them an initial charge, and let the Amis take it from there. Or, if you have a cordless phone lying around and it uses 3.6V, just use that.
NOTE: For those wondering, the charge rate of NiCds, to prevent them from "gassing" or blowing up, should be about 1/10 (10%) of charge capacity. So, with the original Varta 60mAH, this puts it at about 6mA, which is just what you get from the circuit on the mobo. Switching to a 300mAH allows you to ramp it up to 30mA, but I didn't want to play with the mobo anymore than I had to, so I left it at 6mA. Still safe, and still charges, albeit rather slowly. I've also seen external battery packs sold for older PCs (386 and earlier) that tap into the power supply using a standard Molex©, and has leads that fit onto the standard mobo battery connector.
banzai