As far as I recall a charging state of about 65 % is recommended. This reduces internal aging as much as possible.
In general chemical reactions are slower at low temperatures. I guess around 10 °C in a non-condensing environment would be good.
Let me add myself to the list of happy Imax B6 charger owners. I bought it about 4 months ago when one of my hard-case 4S 5000 mAH LIPO batteries stopped charging to full capacity, replacing a charger that I bought 6 years ago. The new technology in the Imax recovered the battery in that it now charges fully.
By the way, the IMAX supports LIPO LiFePO and several other technologies.
What’s this point about not using the batteries in the colder months Eric? My radio batteries get used more when the winter bonus points are available HI.
Because I thought that my Imax B6 clone (a RC-Power BC6) was not able to charge LiFe batteries but I double-checked and I was wrong ! So this 8 years old charger (I have to change the DEC / INC buttons) is still working ! Tks and 73
ISTR the manual for mine (same charger but with built in AC PSU) is in OK English… it tells you what the buttons do and what to press but doesn’t explain why you would want to do some of these things.
I use my Li-ion charger XC-12610 for both HB-1B (I do not know its parameters) & KX2 (2,6mAh) batteries.
For HB-1B it works for 2 winter activations, for KX2 for 1 activation.