I notice the flat LiPo batter (CE04378) has undervoltage protection. What voltage is that set to?
I assume the 18650 batteries (CE04625) don’t have undervoltage protection integrated? Would you have a suggestion for an interface converter to 3.3V that provides the protection?
Hi JRGR, Welcome to the forum,
The datasheet for the CE04378 lists the over discharge protect voltage at 2.4V ± 0.1V. Which seems far too low to me to avoid reducing the life of the LiPo cell.
I’ve heard some people say a nominal 3.7V cell should be operated around half a volt above and below the nominal cell voltage (3.2 to 4.2 Volts). Some people will discharge down to 3V but 2.4 volts is the lowest I’ve seen by far and I wouldn’t trust it.
18650 LiPo cells like CE04625 do not have any form of protection and it is assumed they will be integrated into a battery management system that will protect them.
I can’t find a battery charger / management system that outputs directly at 3.3V, most output at 5V. But it wouldn’t be too hard to have something like this management system that feed this regulator to get 3.3V output.
I’m encapsulating this prototype so battery protection is important. 3.4 seems very low, my understanding is there is not much point in taking the cells below 3 of even 3.3 if you want good cell life. Most of the capacity is above that voltage.
Much appreciate your help.
I’d agree completely, just because there is a battery protection board on the LiPo pouch doesn’t mean the battery’s lifespan will be preserved, but there is nothing stopping you from using that same LiPo pouch with a battery management system that will hold that battery within a good operating range.
Sorry to continue on with this.
I had a look at the GEB spec for the LIPO 603450 (MSDS for those refer to GEB as the manufacturer) and that spec has the PCM Over Discharge Voltage level at 3.0V which differs from the spec of the PCM you link to. I’d prefer to use the 603450 batteries. 3.0V level will give a much improved battery life in my application so the minimum I’d like.
Question, I guess, is which spec is the correct one?
We recently updated our product pages with information provided by GEB. Could you send through the link to the page where you found the different information?
P.S. You’ve probably found it already, but the 603450 is CE04377
Seems we’ve got some work to do double checking our product pages. We’ll do some more research then get back to you with a verdict. I’d err on the side of caution here (assume any batteries from our stock feature the 2.4V PCM) And go from there.