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I recently learned that rechargeable lithium-ion AA batteries, 1.5VDC 3200mAh, have become available. For instance:

https://www.amazon.com/EBL-USB-Rechargeable-Lithium-Batteries/dp/B0828KRQZ3

https://www.google.com/shopping/product/13543601031434520708

Can a charger supporting >3V Li-Ion and 1.2V NiMH batteries, be used for these? And if not, what would be the necessary technical changes?

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  • \$\begingroup\$ Hi! Welcome here. You're sadly asking for a product recommendation. These are explicitly off-topic here, to avoid flooding this platform with these. However, I think it would be rather easy to re-work your question to be just "can a charger for > 3V LiIon batteries be used for these? And if not, what would be the necessary technical changes?", but to be honest, never heard of 1.5 V lithium batteries, and they seem to be impossible to me. Could you, if you decide to rework your question anyway, also include a link to sad battery, especially a datasheet to one? \$\endgroup\$ Oct 24 '20 at 12:57
  • \$\begingroup\$ Done, Marcus, and thank you. \$\endgroup\$ Oct 24 '20 at 13:08
  • \$\begingroup\$ Questions on the usage of consumer products are not on topic. This site is for design questions only. For this to survive, you would need to link to engineering data sheets of both the battery and the charger - not sales pages. \$\endgroup\$ Oct 24 '20 at 14:05
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    \$\begingroup\$ Sold by... EBL official not Amazon.com. So it's eBay/BangGood-tier junk off the boat. (they just happened to have shipped a containerload to the Amazon warehouse, somehow getting them around product-safety rules). However, since it's not AC mains equipment, no big deal... what could go wrong? \$\endgroup\$ Oct 24 '20 at 19:03
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You can't charge such batteries via their +/- terminals. These must be charged through micro USB port on the side. This is confirmed on Q&A of the product page.

Basically these are casual 3.7V Li-Ion chemistry inside with some step-down DC-DC module built-in. And a charger circuit which actually charges them from 5V USB as a casual Li-Ion cell charger.

Due to this their discharge curve are pretty flat. You'll get almost constant 1.5V until a Li-Ion actual cell voltage drops to somewhere around 3V where internal protection circuit just cut if off and you'll get 0V output. So you can't charge it with such chargers as it won't drop below 1.5V like normal NiCD/NiMH cells do. Even if you apply higher voltage on +/- terminals basically you'll apply it to DC-DC output.

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  • \$\begingroup\$ Got it! That is very helpful. Any idea about these? They look like they charge via terminals, though advertised as only from that vendor's charger. amazon.com/dp/B07QV8GYV3 \$\endgroup\$ Oct 24 '20 at 13:18
  • \$\begingroup\$ @JEBofPonderworthy these seems to come with a special charger I guess. At least on the product screens tells "Output voltage of the charger is 4.2V". So basically no, these can't be charged by 1.2/1.5V AA charger. As for the Li-Ion charger 3.7/4.2V seller tells that these can't be used too on the product Q&A. They suggest to use only their branded charger which is included with a pack of 4. This might be true due to the DC-DC circuit inside those cells. But can't tell for sure without seeing it's schematics which isn't available. \$\endgroup\$
    – NStorm
    Oct 24 '20 at 13:25

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