When I first converted to 6V I did not have a proper charger and was told that I could use my 100ma Futaba wall charger that came with my 9CAP. I was charging 1650mah packs. I found that the wall charger did in fact work fine. I had to leave it on quite a long time as much as 36 hours, but after charging the pack it did in fact read 6.4 volts. I actually used the wall wart for several months with no issues. I would fly five or six 13-minute flights and my voltage still remained above 6V. I've since aquired an Einstein XL that I've been using to charge abd cycle my packs and I now have an Accu-cycle Elite on backorder that I will use once I get it. But the bottom line is that the wall charger worked fine with my 6V packs.