Mobeen Posted May 16, 2022 Report Posted May 16, 2022 Hi, I created a couple of router UPS (2s and 3s) according to the attached circuit diagram, minus the voltage display. They work fine except that when batteries are completely depleted and output is turned off, it doesn't give the necessary output after the power restores until I turn the circuit off and on again manually through the on/off button. My router's light blinks in a cycle for a brief moment and turns off as if it is not getting the necessary voltage/current. Can someone help me resolve this problem, please? I used this YouTube video as a reference to build these circuits: Quote
HarryA Posted May 16, 2022 Report Posted May 16, 2022 If you do not see the 8.4 volts at the 5v to 12v converter it suggest that the power supply has gone into a thermal overload state. Perhaps due to the drain from the charger. Switching it off resets it perhaps. Quote
Mobeen Posted May 16, 2022 Author Report Posted May 16, 2022 16 minutes ago, HarryA said: If you do not see the 8.4 volts at the 5v to 12v converter it suggest that the power supply has gone into a thermal overload state. Perhaps due to the drain from the charger. Switching it off resets it perhaps. @HarryA For 2s setup, I am using 8.4v 1A charger and for 3s, 12v 1.5A adapter. Do you think that using 12v 2.5A or 3A can fix this issue, at least for 3s circuit? Quote
HarryA Posted May 17, 2022 Report Posted May 17, 2022 If you use a 12v and 3 ampere charger that would require a little over 36 watts. A 12v and 1 ampere charger would be about 12+ watts. That would be less load on the power supply. Assuming the power supply is the limiting factor here. The slower charge rate would not be a problem if you do not have power outages more than once a day? Quote
Mobeen Posted May 24, 2022 Author Report Posted May 24, 2022 On 5/17/2022 at 6:06 PM, HarryA said: If you use a 12v and 3 ampere charger that would require a little over 36 watts. A 12v and 1 ampere charger would be about 12+ watts. That would be less load on the power supply. Assuming the power supply is the limiting factor here. The slower charge rate would not be a problem if you do not have power outages more than once a day? @HarryA What do you mean by charger here? I am not using any charger but instead a power supply of 12v 1.5A connected directly to the circuit. Are you suggesting me to use a 12v 1A power supply instead? Quote
HarryA Posted May 24, 2022 Report Posted May 24, 2022 Your BMS (HW-391): Product Model: HW-391 Charging Voltage: DC 8.4-9V Version: Balance Constant Discharge Current: Max 20A (If the heat dissipation environment is not good, please reduce the use of load current) Constant charging current: Max 10A) https://makerselectronics.com/product/lithium-battery-charger-protection-module-bms-2s-20a-7-4v-balanced-version Some say a BMS (battery management system) is not a charger but there seems to be come confusion here. One thing that is not clear is what is the nature of your 8.4 volt power supply. Also is the BMS preventing the battieries from discharging below the allowable voltage level for a li-ion battery. Quote
sadfsa3 Posted May 8, 2024 Report Posted May 8, 2024 I purchased the HW-391 module under the impression that it supported both charging and balancing functions. I intended to use a 9V input voltage, which I believed was within the acceptable range for charging. However, I'm having second thoughts now. Has anyone successfully constructed the circuit mentioned in the original post using a 9V input voltage? Quote
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.