Macintosh PowerBook 160 (1993) Battery ReCondition

I have successfully reconditioned the battery on my PowerBook to what I think will be its maximum life span (and probably the last time its ever used by an owner). How did I do it? Simple, zap it with a 20 volt laptop charger. These old PowerBook's had a 6 volt Ni-Cd battery (Ni-Cad) and they would do two bad things in their life; one being the battery gaining the "memory effect" and the other being it just wont charge at all. This was pretty simple to fix because most Ni-Cd batteries work the same. The memory effect is caused when you discharge the battery to a less-than-empty state and then recharge it to full again. It doesn't just happen with one time though, it happens over many cycles of not draining it all the way. After doing so, it seems to think that the point you drain it to is the maximum it can take so it wont discharge past that point (It "memorizes" where you discharge it to). The suggestion from Apple was to discharge the battery all the way every 90 days and then charge it for an extended period of time. Sadly, this problem was not very fixable on this PowerBook.

The problem of it not charging comes from leaving it not charged for an extended period of time (a month or more) and it is very easy to fix. If the battery has not "dried out" or leaked, the likely problem is crystals forming on the inside and shorting out both terminals. To fix, simply apply a large amount of power (at least twice the rating of the battery) for about 3 seconds at a time in intervals of 10 or so seconds. This will melt those crystals and return it to a semi-working state. After doing so though, be sure to recharge it overnight using the STOCK charger.

After zapping it, charging it as much as it could, then running it down completely, and finally charging it for 1 and 1/2 days, I was able to get 2-3 min of battery life with the brightness up and the hard drive spun down. With the hard drive spun down and the brightness all the way down, I was able to get a whopping 6 minuets out of the original 1993 battery!! Of course, in todays standards, that is completely useless, but it's something to say for old technology!



Comments