18650 / newbie board / boost??

[CrankyCoder]

I have a the fantastic newbie pcb board from @sundberg84 and I am making a small pool temp sensor with it.

I am running in to some issues though and wondering if anyone has some ideas. So a fully charged 18650 can get up to 4.2v so I need to regulate it. I was looking to put the battery in through the RAW pin that way the VCC would be 3.3v. However, that is only good until the battery drops below 3.3. The 18650's I am using can go to 3.0 pretty easily, datasheet even says 2.8. 3 is kind of where I would like to limit it though. So I have a little 3.3v boost converter. But when it's over 3.3v not sure if it's going to damage the boost converter (guessing yes).

So i am curious if it's possible to be able to use the newbie board, have the battery voltage monitored. Handle a fully charged 18650 and be able to use the boost converter if the battery drops below 3.3v.

Thanks!

[rozpruwacz]

@crankycoder use 3v ldo istead of 3.3v ldo. Evereything will work at 3v without problems and you get almos full battery capacity.

[alexsh1]

@crankycoder you can use a LiFePO4 18650 Rechargeable Cell. Its voltage is lower. Nominal voltage is 3.2V

[CrankyCoder]

@rozpruwacz gonna have to check in to this. i have lots of 3.3 but no 3.0 ldo's

[CrankyCoder]

@alexsh1 the reason i am using the 18650's is the fact i have a steady stream of them coming in for my large battery packs. I have a couple hundred that aren't dead but just aren't quite up to to the standard i am putting in my big packs.