> On 1 Feb, 2019, at 10:39 pm, [email protected] wrote: > > The batteries are dead but it will run off of the AC adapter. Any solution on > the batteries?
I once, many years ago, took apart a pair of PB 190/5300 batteries. They contain a load of approximately AA-sized NiMH cells soldered or spot-welded in series, plus some electronics for type-identification and charge management. I was able to parallel my two batteries to overcome the high resistance the old cells had developed, and actually obtained 5 hours runtime from a pair of batteries that had originally provided 1 hour each at best when new, and less than 15 mins each when aged. I take that as a sign the batteries were undersized at design time (a common problem with laptop batteries, as size/weight gets prioritised over utility). I understand a Li-Ion battery was planned for the 190/5300 but wasn't ready in time; also NiMH batteries generally last longer in years, though not in hours. In theory, you should be able to construct a fresh battery using ordinary AA NiMH cells (get industrial tagged ones which can be soldered together, not the retail ones which need a holder) and the old casing and EEPROM. However, according to https://68kmla.org/forums/index.php?/topic/29344-powerbook-500-series-battery-rebuild/ the electronics in the 500-series battery is "smarter" and more finicky than the simple EEPROM I found in my batteries. There's a lot of info in that thread, actually. - Jonathan Morton -- -- ----- You received this message because you are a member of the Vintage Macs group. The list FAQ is at http://lowendmac.com/lists/vintagemacs.shtml and our netiquette guide is at http://www.lowendmac.com/lists/netiquette.shtml To post to this group, send email to [email protected] To leave this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/vintage-macs Support for older Macs: http://lowendmac.com/services/ --- You received this message because you are subscribed to the Google Groups "Vintage Macs" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
