On 11/13/18 6:08 PM, wrote:
Mark, When K2 was fairly new on the market I contacted them asking if Battery Tender Jr. is okay and safe, they replied that it is perfectly okay and nearly the same as their charger. I also contacted Battery Tender Jr. with the reverse question and they said the BTJr is fine for LiFePO4. I used the BTJr for years on my K2 with no issues. They're about $25 on internet sites.


Have you measured the amount of charge you're getting into the K2's? It
will be considerably less than the rated amount due to using a lead-acid
charger.

Also, if K2 has cell balancing capability, it won't be used because your
Battery Tender doesn't put out enough voltage to make it work.