Can I Plug this RTC straight into my LiPo battery?

1

12Cronut

Member
Joined
Nov 3, 2025
Messages
5
I'm trying to figure out if I can hook my super low power RTC directly up to my battery.

My plan is to build a little charger/power board for my projects, and I want the RTC to sit there, sipping tiny amounts of power, and then wake up the whole system with an alarm.
The idea comes from a Chinese circuit I reverse engineered. the RTC is always on, and it kicks the main power regulator into gear when an alarm goes off or a button is pressed.
The problem is the datasheet says the absolute maximum voltage is 6.5V, which sounds great, but then every other table in the document shows 3.6V as the max for all the measurements and operation specs.

idk what the deal is here. Can this thing handle the full voltage of a LiPo and run normally, or is the 3.6V number the real cutoff?
 
Ran into that same spec mix-up before, 3.6V is the true limit. The 6.5V is just for survival not really safe for regular use. You might want to add a small regulator.
 
yep, don't do it directly! the 3.6V is the recommended operating voltage
If you put a fully charged LiPo (4.2V) on it, you risk inaccurate timing and chip damage over time. the 6.5V is just the max rating point.

try to use a super low power LDO to regulate the battery voltage down to 3.3V. this is the safest way to make sure the RTC stays accurate and sips power for years
 
Good advice, regulating down to 3.3V really is the safest long‑term move.
 
if you want your RTC to last for years on a single charge, look for a Nanopower LDO like the TPS7A02
it has an ultra low quiescent current of only 25nA. at that level, the regulator itself sips almost as little power as the RTC, so you aren't wasting your battery just to keep the voltage steady
 

Latest posts

Back
Top