Received prebuilt battery and few elements:
Big one is pretty heavy and overqualified for QRP 🙂 18Ah is enough to drive 100watt transceiver for around 1 hour in PTT mode.
So I want to have small one for QRP and receiving.
Unneeded PCBs:
Sawed 🙂
As I not assembling batteries in general, so I don’t have spot welding so I solder with acid. Heating is bad for batteries, but I have no choice:
Putting batteries to textolite box and soldering BMS wires. Applying thermal clue — novadays it’s like blue insulating tape in USSR :
Checking BMS connection via bluetooth. Displaying capacity is wrong, reflashing of BMS required:
It’s not possible until you buy pro version of app. Greedy guys. Isn’t enough that I bought BMS? ADs in APP, seriously?!
Finishing:
Before fully assemble let’s charge it and test capacity:
Discharging:
At 6000mAh voltage start dropping below 3v on each cell — so I can stop dischrging, so capacity is good:
According to the datasheet discharge cutoff voltage = 2v. But I’m not discharging them lower than 3v in normal conditions.
Final look:
