Hi Guys,
To save power loss I am thinking of removing on board Voltage regulator form Moteino R6. I am powering my device from 4 18650 2000 mAh batteries connected in parallel.
So input power would be between 3.7 ~ 4.2V with 8000mAh capacity. I know Atmega328 should be fine. Question is if RF module would be ok ? According to its datasheet its input should be upto 3.6V
nor radio nor flash will support 4.2V when your batteries are full.
You could change your batteries for LiFePo4 who are between 3.6 (full) and 2.5~3V, but they give less power for same size (18650 are around 1200mAh)
I wonder if removing the LDO in your case is really relevant, since you will gain some µA (less than 10 when sleeping, some hundred at full load) but if you need 8000mAh, your consumption is probably around hundred mA ?
Quote from: Uncle Buzz on April 05, 2018, 10:58:18 AM
nor radio nor flash will support 4.2V when your batteries are full.
You could change your batteries for LiFePo4 who are between 3.6 (full) and 2.5~3V, but they give less power for same size (18650 are around 1200mAh)
I wonder if removing the LDO in your case is really relevant, since you will gain some µA (less than 10 when sleeping, some hundred at full load) but if you need 8000mAh, your consumption is probably around hundred mA ?
Yes my consumption is around 150 mAh. So it sounds like keeping the LDO is only option ? Other issue i can see with that, as soon as battery voltage is below 3.6V it would stop working whereas without LDO atmega could run at alot less then 3.6V ?
I am not using flash anyway.
For such purposes there is the LDO-less Moteino (8Mhz) (https://lowpowerlab.com/shop/product/159). Runs from anything below 3.6v, sips power, and can even run on coin cells (with a little care WRT radio/FLASH).
For anything above 3.6V you will need to regulate for the radio/FLASH.
Quote from: malik on April 05, 2018, 11:55:49 AMOther issue i can see with that, as soon as battery voltage is below 3.6V it would stop working whereas without LDO atmega could run at alot less then 3.6V ?
Everything should work until 3V and lower (not much power in Li-ion under 3V), the LDO will consume more but won't cut anything.