So, I can get these batteries very cheap - less than $2 a piece. However, I have no real idea how to use them. (I intend to power a robot with them if I can.) So this begs the question: what kind of batteries are they? Are there commercially available chargers, or is this some kind of specialty unit?

Is it possible to (safely) build your own circuit around these? I feel almost like this is a little off topic, but honestly I don't know where else to ask this question, as I don't know where to start.

Thank you kindly.

enter image description here Edit: I don't know how much it means, but the were dumped en mass and they have a self-test function on them... some of them are even full (varies quite a bit.)

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    \$\begingroup\$ What does the datasheet for the battery say? What does the man, who sells you these batteries for $2 say? That's where you should ask this kind of question. \$\endgroup\$ Nov 7, 2014 at 19:09
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    \$\begingroup\$ Maybe they are all dead. That's a good reason for them to be in a recycling center. \$\endgroup\$
    – Ricardo
    Nov 7, 2014 at 19:34
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    \$\begingroup\$ Guys, don't encourage people to buy batteries from recycling companies. These companies sell a lot of batteries to not responsible people who just throw them away if they are not working. Lithium is very hazardous substance. These batteries should be recycled, not sold to random people. \$\endgroup\$
    – Kamil
    Nov 7, 2014 at 20:14
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    \$\begingroup\$ @Kamil: I've thought about it, and you're right. It's one thing to tear a battery pack apart, recycle the electronics, test the individual cells, and then sell them off as "refurbished", and quite another to outright sell people junk. \$\endgroup\$ Nov 7, 2014 at 20:18
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    \$\begingroup\$ I fear those who have a moral compunction to selling junk have access to resources others do not. I make minimum wage+some. Put me on social security or raise minimum wage if you don't like me buying junk - wage slaves like me (can) come financially relatively ahead with a moderate amount of skill. My $120 coffee maker was $2 bucks (clogged). My Linux box was $15 bucks (PSU fan). Depends on how sales are treated, really, if it's ethical or not - pricing on the very edge of risk is unethical. \$\endgroup\$ Nov 7, 2014 at 22:10

2 Answers 2


Bottom one is single use (not rechargeable!) battery for heart defibrillator.

These are sold for 2$ price because it's easier to sell them than recycle.

Recycling cost money, so they sell them on ebay or elsewhere to avoid responsibility. Someone buys them and at some point throw them away or... pay money for recycling to company that maybe will sell same battery again.

Don't buy batteries from recycling companies. Don't let this proceder continue and grow.

Lithium is hazardous substance and these bastards should recycle batteries, not sell them to random people after someone (or government) paid for recycling them.

  • \$\begingroup\$ It seems like somebody was at least trying to recycle them but the recycling company had their own ideas what that meant. \$\endgroup\$
    – Octopus
    Nov 7, 2014 at 20:48
  • \$\begingroup\$ Anyway, my point is, how does one recycle a battery if the center you take them to just sells them for $2 to others? \$\endgroup\$
    – Octopus
    Nov 7, 2014 at 21:00
  • \$\begingroup\$ I think many batteries supposed to be properly recycled just end on "regular garbage" after one or more "resell cycles" like this. \$\endgroup\$
    – Kamil
    Nov 7, 2014 at 22:22
  • \$\begingroup\$ I could argue the center didn't make too much note of the fact they even had them - they let you rummage - but you have a point. I would just return them (for free) if they don't work. I'm kind of surprised this doesn't' seem to be regulated, now that you mention it :/ \$\endgroup\$ Nov 7, 2014 at 22:26
  • \$\begingroup\$ Actually @Kamil, do you think it is unethical for me to contribute to this practice by buying? Ironically, the fact I am responsible enough to care means that it becomes more likely for people who don't care very much to buy them if I don't.. \$\endgroup\$ Nov 7, 2014 at 22:48

They are proprietary battery packs, most likely for a single model or range of models of laptops or similar. They will consist of multiple battery cells in series and/or parallel, heat sensor, eeprom, and ic (s) for monitoring battery health and state.

With some effort and multiple of the same type including one to sacrifice open you can easily reverse engineer them. But likely they are dead or near dead for reasonable high voltage and amperage usage in a robotics setting...

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    \$\begingroup\$ I agree with your answer, you missed one fact. Bottom battery on photo is LiMn02 (not rechargeable). However top one might be LiIon, I can't see text clearly. \$\endgroup\$
    – Kamil
    Nov 7, 2014 at 20:07
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    \$\begingroup\$ While I appreciate the effort of answering the question... I would never encourage a random guy on the internet to open them up. Most of the time Li batteries just splutter a bit when exposed to humidity, but I've seen a few launch a fireball out of it's edges. Lithium is highly reactive, best to dispose of the batteries at a recycling plant (where he oddly bought them) than to try and reuse them. \$\endgroup\$ Nov 7, 2014 at 20:20

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