OT - 18660 batteries and why would it get hot?

[3rutu5]

Guys I've had this one a few 18650 or CR123A batteries, I've had them in a battery holder, hooked up to a booster module attempting to tune the output voltage and noticed that the batteries get really hot to touch, but if I did that with a expensive Panasonic one it doesn't do that at all?

Yes that are all rechargable, not sure if they are protected cells.

I'll be completely honest, I'm only putting together my first battery build and think that this is a concern, but haven't don't it before so don't know if this is normal or enough to start ringing alarm bells.

[Dukk]

I really don't know how familiar your are with batteries but..

All batteries are rated by Voltage, Capacity, and Current delivery. Voltage and Capacity are almost always listed, eg 3.7v and 600mAh. What isn't always immediately apparent is the current capability of the battery - some don't even list it on the battery. This will be listed as the C rating of the battery such as 10C, 15C, 40C, etc.. The C rating, along with the capacity, combine to determine the maximum current the battery can provide. So if you have a 600mAh battery with a 10C rating, it can deliver 6000mAH, or 6amps of current. A 600mAh battery with a 30C rating would have 3x the current capability, or up to 18amps of current. Attach a load of 8 amps to both of these two batteries and the first one is going to get HOT and likely get damaged where the second one will be ok. I suspect this may be your issue with the less expensive batteries - you are approaching or exceeding the total current delivery limit of the battery where the higher quality Panasonics may be higher current so they tolerate the draw.

[3rutu5]

Interesting, yep I'm not familiar at all with batteries, but interested in learning a bit more in this area.

I guess if all I had connected was a adjustable voltage booster I would never had thought about the actual draw. So really I should be looking at the specs of the voltage booster as well, as I only was looking at output voltage

[devnull]

18650s should never get hot, warm is ok. Thermal runaway is a known problem. You should be using a controller matched to the batteries and the load. Buy them from a reputable distributor, not Ebay or salvage them from old laptop battery packs. Google li ion thermal runaway and take a look at some of the videos.....

[3rutu5]

This was the one that got hot, I also got the Panasonic from them so happy with the dealer, I just went the smaller batteries as a test as they are quite small

https://www.ausbatteries.com/lithium...m-battery.html

[DeanIO]

For batteries, I've always trusted Liion Wholesale

https://liionwholesale.com/

Only place I know of to buy "genuine" Sony VTC4s, atleast when they're in stock.

[buggers]

This is not the classified section.

[fpitas]

This is not the classified section.

I reported him. At least he's not pushing an essay writing service.

[buggers]

Lol I hear you