Where do people buy reliable 18650 lithium batteries these days? Anyone got links?
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Problem statement: I have some portable test equipment that currently uses a (weird) 12V barrel jack and a 5-cell NiCad battery pack, with a charger built into the test equipment PCB. Naturally, this has died. I’d like to replace the battery pack with a single 18650 (NiCad was 1.2V x 1800mAh = 10.8Wh, 18650 1S 2600mAh = 9.62Wh) and pipe 12V straight to the barrel jack input, using USB-C for the charging and power instead. Surely there are boards for this on the market already, right?
I am going to build myself a board that does this. USB-C in, 2S 18650 pack, TI BQ25886 charger IC with a boost regulator on the output to get 12V. How hard can it be?
@ThermiteBeGiants calling @jpm to the thread...
@Kels_316 @ThermiteBeGiants If you really do want to go down this path, take a look at the BQ25640 instead because it's already got all the USB PD protocols baked in. Only a 1S chip, but stick a bunch of cells in parallel and a boost converter on V_SYS output to get it back up to 12V
@ThermiteBeGiants @Kels_316 the PD stuff is quite handy for quickly charging the batteries at full herps
@ThermiteBeGiants @Kels_316 SYS tracks the battery pin voltage usually. From memory they datasheet doesn’t make that clear
@jpm ah, even when there’s no battery? Oh well, I’m shoving it into a regulator anyway.
@ThermiteBeGiants USB-C PD trigger set to 12V, and a normal USB-C power bank.
@jpm only problem with this solution is that it’s not internal and I really need to have the battery inboard for the clock. When there’s no battery the thing does a really annoying NVRAM checking cycle that can take up to a minute
@ThermiteBeGiants or skip the PD trigger entirely. AliExpress gotchu fam.
@ThermiteBeGiants LiitoKala. Slow shipping, but expected for spicy packets of electrons.
liitokala Official Store
https://a.aliexpress.com/_mrGOkJV
