Spare Pandora Batteries - testing, charging and storing

[b_o_b]

Bought a bunch of batteries from DragonBox. They are for sale so I guess ED is cleaning out the basement I am still planning on using my Pandora's for a while so nice to have enough spare batteries for the next few years.
My method is checking the batteries first and charging them until they are charged between 40-60%. Identify, store them and then check again once every year.
The advise I've seen for storing was not charging them full and not letting them drain completely. Good method?

They all have ID# number 0413 on them so I think they are one of the older batches and might be >10 years old. Maybe @EvilDragon can confirm?

All but 1 battery had enough charge to power up my Pandora's (still need to check 2 batteries). A lot of difference between batteries, some had nearly 0% charge and some still 50-60%. Nice to see that most of them still work.
1 battery seems to be dead, I've tried two Pandora's to charge them - via Pandora and PSP adapator, USB, and even both at the same time. Multiple articles mentioned to place a dead battery in the fridge for 24 hours then leave it at room temperature for 8 hours to revive it.
So it is now in my fridge and will give it another try tomorrow. If it fails no problem, the batteries are currently dirt cheap and I have plenty now.

 

[EvilDragon]

413 means they've been produced April 2013.

 

[levi]

I've never heard of the trick to cool batteries in the fridge to revive them, but I have heard about freezing them to try to stop them self-discharging so fast. You need to put them in a plastic bag and evacuate all of the air from inside it for that.

But yeah, the method of charging things to about 60% is what I use when I'm not planning to use the battery for a while. I've not yet played with freezing them.

 

[b_o_b]

413 means they've been produced April 2013.

Nice - I' ve also got 1609 and 3910 and are still working. They are from 2009/2010 then?

I've never heard of the trick to cool batteries in the fridge to revive them, but I have heard about freezing them to try to stop them self-discharging so fast. You need to put them in a plastic bag and evacuate all of the air from inside it for that.

But yeah, the method of charging things to about 60% is what I use when I'm not planning to use the battery for a while. I've not yet played with freezing them.

Freezing is just for the one battery that appears to be dead. I hope to avoid that for the remaining batteries by checking them once every year and keeping them charged.

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[levi]

It says for dead batteries you (a) need to clip it to a live battery to 15 minutes and (b) charge it fully then discharge it before (c) freezing it. Seems rather over complicated, which suggests they don't quite know what works. I guess stage (a) trickle charges the battery. I have a dumb slow charger I use for reviving dead NiMH cells that have self discharged too far before my fast charger will be happy enough to charge it. I guess stage (b) proves the battery is capable of taking a charge and then doing work, and (c) is to cool down the now hot battery.

 

[EvilDragon]

Nice - I' ve also got 1609 and 3910 and are still working. They are from 2009/2010 then?

Correct. Though I made a mistake with the 0413: It's not month/year but week/year.

So the batteries have been manufactured week 16 2009, week 39 2010 and week 4 2013.

 

[b_o_b]

It says for dead batteries you (a) need to clip it to a live battery to 15 minutes and (b) charge it fully then discharge it before (c) freezing it. Seems rather over complicated, which suggests they don't quite know what works. I guess stage (a) trickle charges the battery. I have a dumb slow charger I use for reviving dead NiMH cells that have self discharged too far before my fast charger will be happy enough to charge it. I guess stage (b) proves the battery is capable of taking a charge and then doing work, and (c) is to cool down the now hot battery.

Indeed, I haven't done that. Too much hassle, just freezing it and trying again is the only thing I was willing to try out and and unfortunately didn't work. The article is mentioning Lithium Ion batteries and not Lithium Polymer, so maybe the method only works for Lithium Ion batteries. Also saw a video's of people reviving LiPo batteries starting with very low amperage. They usually have equipment I don't have. No problem, I've got more batteries than I need.

Correct. Though I made a mistake with the 0413: It's not month/year but week/year.

So the batteries have been manufactured week 16 2009, week 39 2010 and week 4 2013.

Thanks, that makes sense. Incredible how well these batteries still perform, even the 2009 batteries.