Recovering PB100 batteries

[aladds]

Has anyone tried recovering a PB100 battery?

There are a number of guides online regarding recovery of SLA bateries like the one the PB100 has... and having a look at the battery, it's pretty easy to pop the top & remove the caps to get to the cells.

I realise these batteries are getting pretty damn old now, but it's entirely possible that if they've been dry for 10+ years they've not gotten *that* much worse?

I might by some deionised water and try it out!

 

[aplmak]

I don't know how you can get into a PB100 battery.... It's sealed... or are you talking about another battery in the 100 series? I know there have been multiple people on here who have tried to make a PB100 replacement including myself.... but it hasn't been easy.. 360alaska has made a 3D printout of a shell...

 

[bibilit]

probably can be hacked, i have seen something about it, but not as easy as the Portable ones, the PWB 100 battery is pretty thin, no available cells are a direct replacement.

Not a big deal either, the Powerbook works anyway without. 

 

[asaggynoodle]

Should be doable. At that time, there wasn't any kind of power controller for the battery cells itself. So, you can just replace the cells as long as it's the same voltage and be good to go. I'm sure you can hack mostly anything you want in there.

 

[CC_333]

One wouldn't be able to recharge it though, unless they put it in an external charger designed to charge whatever cells are used (trying to charge it using the PowerBook's circuitry could cause catastrophic damage to the battery, the PowerBook, and potentially the user).

Or am I missing something?

c

 

[360alaska]

I was working on a lithium battery, I need to pick that project back up...

 

[asaggynoodle]

One wouldn't be able to recharge it though, unless they put it in an external charger designed to charge whatever cells are used (trying to charge it using the PowerBook's circuitry could cause catastrophic damage to the battery, the PowerBook, and potentially the user).

Or am I missing something?

c

You're completely right.. Most of the modern (Atleast LiPo) cells I've seen have built in over/under charge circuitry. So at least the Battery itself would be fine, but I'm not at all sure how a lead acid charging circuit differs from any other like with a NiMH etc. Recharging could be handled in a number of ways, if the laptop itself couldn't do it, you could add a super simple 19.5v Step down charging circuit to use with a normal laptop charger. Or even have some AA rechargeable Sanyo Eneloops in a 3D printed tray, and just pop them out to charge. But that would be very manual and tedious. 

 

[aladds]

I think you misunderstand me.

The batteries consist of 3 2v lead acid cells. They're "sealed" in that they don't have obvious screw caps to top them up, but pop the end off and there are three rubber caps which allow venting, but also access to top them up!

Have a look here: 

 

[aladds]

Before starting I had 0.1v across this dead battery.

So I bought some water, squirted it into the cells (they take a lot!), stuck it on a high-current 5v supply for about 5 minutes and got it to about 2.5v.

After this I put the caps back on, taped the cover in place and stuck it in the powerbook...

5 minutes later I'm getting 3.6v, although the battery meter is constantly showing full (although it does that when there's no battery too, not sure what that means exactly...)

I'll give it some more time and see how it goes.

 

[bunnspecial]

Are there any other PowerBooks that use SLA batteries?

I have a couple of 500 series batteries and it would be great if I at least had a shot at reviving them without a complete rebuilt. I seem to recall those being NiMH, but I'll certainly give this a shot if they are SLA.

 

[aladds]

Just the Portable (which is easier to rebuild as they're huge) and the 100 use SLA.

TBH it's not that bad, as even if the recovery is successful I doubt I'll get much capacity; these things only got 2-3 hours new!

 

[BadGoldEagle]

So what's the voltage on that battery after a proper charge? I have a PB100 and I'll give this a shot when I have time.

 

[aladds]

It's been charging for the last 6 hours or so and it's up to 4.9v.

That's still way less than even 10% full, which would be 5.75v, but it's actually not bad, considering.

I'm hoping another 12 hours or so should do it!

See the column for a 6v battery

 

[techknight]

Hit it with a desulfator afterwords and that battery will last nearly as long as new. 

I did this very same thing to an old Sony Discman D-7 which uses a very similar SLA that attaches to the bottom. After the water and charge trick, I let it sit on a desulfator trickle charger for a couple weeks, and the battery would fully charge and last hours. 

https://www.amazon.com/BatteryMINDer-Charger-Desulfator-Batteries-Model-2012-AGM/dp/B005EKY20K

 

[aladds]

I actually have something very similar for my motorbike. Annoyingly it only does 12v batteries. Good thing I have a few of these! Once I've got this one to at least "50%" I'll do a second, then put them in series on it.

A lesson I've already learnt: don't put too much water in! I'm not sure the best way to know how much is too much, but when they leak all over your powerbook it's not fun to clean up! :-S

 

[aladds]

Got the first two on the charger.

Number 3 I don't think I can recover, as it's rattling. I suspect the plates have disintegrated.

 

[james_w]

Always nice to learn something new! I had no idea this was possible

 

[aladds]

One of them is now good enough to boot it up!

I get a "your battery is almost dead" message straight away, though, but it's actually quite good progress!

 

[electricmonk]

Hi all, sorry to dredge up an old topic but I'm trying to recover a dead Powerbook 100 battery with only limited success.

It looks like Sony made a few slim lead-acid batteries in the 1980s such as the 6v 1000mAh BP-3 Discman battery and this was clearly where the inspiration for the Powerbook 100 battery came from.

Anyway, I refilled my cells with electrolyte and hooked them up to a constant current power supply delivering 50mA starting at 30v. After a couple of days it self-limited down to 13v but the battery doesn't seem to want to go much higher than 4.41v. I guess I'll just leave it on there and let it bubble away, adding a few mls of water to the electrolyte every few days and see if it comes back to life.

I suspect that one of the cells is in worse condition than the others - only one of them gets warm with the over-voltage.