Macintosh Portable Battery rebuild

[AlpineRaven]

Good evening, 

What are other alternative options do I have instead of using Lead acid battery  - I was thinking about putting 1.5volts AA batteries and join them upto 6volts etc
Is there a possible way to do that?
Cheers

AP

 

[360alaska]

You could but you would want to put a diode to prevent the portable from attempting to charge the Alkalines. I can make you a battery case and you could put what ever you want in there.

 

[IlikeTech]

Or you could use 6 volts of NiMH rechargeables.

 

[bunnspecial]

I know you said you want to get away from SLA, but at the same time it's not difficult to do it with the correct battery chemistry.

Earlier this week, I rebuilt mine with this

https://www.amazon.com/Battery-replacement-QB24-QB26-QUANTUM/dp/B002BJZ2XI

It's a 3 pack of smaller versions of the same SLA cells as used in the original battery. It took me a little bit of finagling and some extra foam inside the case to get it to all fit and line up correctly, but once I did it worked perfectly.

One of the issues you're going to run into with any alternate chemistry is that you really need 6V+. A single lead acid cell is 2V, give or take, while most common rechargeable chemistry these days is 1.5V. That means that you're going to need to pack 4 cells into the pack to get the correct voltage. It's hard to beat lead acid chemistry for power density, and I don't know how you'd get out of an NiMH battery. The original cells were 5AH. The only NiMH cells I found in a quick search with that rating were 1.2V, which means that you're going to need 5 in the pack to get close to correct. That's going to be a tight fit for a C or D sized cell.