· Premium Member
I have had no problems soldering on Li-IOn batteries at all. I make my own packs using 3.7 volt 2600 Mah batteries with built in PCB protection. I use a 250 watt iron, p[lenty of flux and get in and out very quickly. I can make a 14.8 volt pack for less then $30. When using a smart charger the meter shows 15.6 volts at full charge. I get them at all-battery.com very fast service and excellent quality.