ichiban
100 W
I recently bought some powerbank cases with charging/discharging circuit included. They are cheap and useful to utilize our spare 18650s.
Dual USB 8*18650 Power Bank Battery Box Mobile Phone Charger DIY Shell Case :
https://www.aliexpress.com/item/Rovtop-Hot-sale-5V-Dual-USB-8-18650-Power-Bank-Battery-Box-Mobile-Phone-Charger-DIY/32911402208.html?spm=a2g0s.9042311.0.0.7cef4c4dIPSv9C
Some monks I know had to hike over a month into deep jungle for their monkhood activities. They normally use small powerbank to charge phones (for gps) and 2-3 LEDs flashlights for 5-6 peoples and it never lasted a week. Spare batteries are expensive, heavy + no where to charge. When power ran out, they have to make fire afterwards. So I made them one giant 50,000-mAh (1S24P) powerbank from old laptops-harvested 18650s, was afraid that it won't last a month.
View attachment 4
Time was short as parts just arrived that evening and I had hours to finish it from scratch. Not enough time to do much - but manage to wrap it up just in time.
Many of the cheap similar powerbank kits use the same pcb board which is easy. One thing bugging me for a while, I found later that the circuit LV cut-off is around 3.5-3.6V which is too high since there is still some juice left. In this case, we really need to squeeze the remaining power out of the only powerbank available.
Spec (rough) :
1SXP (all parallel) cells
O/P : 5V @2.1A & 1A
over current and short cct protection
BMS not needed since only 1S
View attachment 2
Is there a way to mod it to have LVC 3.0-3.1 V. or even lower (for next charity units) ?
May be next time I'll have to make 100,000mAh.. with wheels on it :lol:
Any idea for this application will be appreciated.
Dual USB 8*18650 Power Bank Battery Box Mobile Phone Charger DIY Shell Case :
https://www.aliexpress.com/item/Rovtop-Hot-sale-5V-Dual-USB-8-18650-Power-Bank-Battery-Box-Mobile-Phone-Charger-DIY/32911402208.html?spm=a2g0s.9042311.0.0.7cef4c4dIPSv9C
Some monks I know had to hike over a month into deep jungle for their monkhood activities. They normally use small powerbank to charge phones (for gps) and 2-3 LEDs flashlights for 5-6 peoples and it never lasted a week. Spare batteries are expensive, heavy + no where to charge. When power ran out, they have to make fire afterwards. So I made them one giant 50,000-mAh (1S24P) powerbank from old laptops-harvested 18650s, was afraid that it won't last a month.
View attachment 4
Time was short as parts just arrived that evening and I had hours to finish it from scratch. Not enough time to do much - but manage to wrap it up just in time.
Many of the cheap similar powerbank kits use the same pcb board which is easy. One thing bugging me for a while, I found later that the circuit LV cut-off is around 3.5-3.6V which is too high since there is still some juice left. In this case, we really need to squeeze the remaining power out of the only powerbank available.
Spec (rough) :
1SXP (all parallel) cells
O/P : 5V @2.1A & 1A
over current and short cct protection
BMS not needed since only 1S
View attachment 2
Is there a way to mod it to have LVC 3.0-3.1 V. or even lower (for next charity units) ?
May be next time I'll have to make 100,000mAh.. with wheels on it :lol:
Any idea for this application will be appreciated.