Cheap batteries

[SrC]

Charging at 1C is the target for Lipos. A Lipo industry standard. Chargers adhere to this standard when cycling lipos. Charging less than that just takes longer. Even way longer than need be. These Lipos are not like Nimpaks or Nicads that will gain distinct advantages when charging below 1C. Storage charging Lipos at less than 1C just takes longer. Being conservative here can be a disadvantage. One being that you are keeping a lipo pack connected to a charger longer than needed. That is a liability. In this situation, a lower charge rate(less than 1C) doesn't equate to any real world benefit. But merely increases the risk of lipo failure because it is connected to a charging source much longer than needed. Lipo fires occur for the most part when connected to a charger. Lipos are the most volatile during charging, regardless of the charge rate.
And I never charge over or under 1C as a rule. Over 1C will tend to reduce the life cycle whether that lipo is rated for more than 1C or not. Under 1C doesn't necessarily equate to longer life cycles. I feel that is an urban myth. Some feel otherwise. I get that.
If I can get 30-50 cycles at min. on my lipos before they are expired or start to fail, or puff (high IR's), that's good these days IMO.
At 1C, if your charger takes more than approx. 45-50 min to fully charge from 3.8v-4.2v, then your charger doesn't have enough watt output for that lipo. The charger is maxed out with no overhead. Or your charger is just tired and bricked. Or possibly a lipo cell that is bricked or on its way out.
Consider an Aux PSU, if your charger accepts DC input. Charging efficiency is important for high capacity Lipos that we use on our rigs.
Just my thoughts on this.

 

[SrC]

I use this on in its duo version. They are solid but also old. You will need a power supply which will add cost. Would have been a premium charger 7 years ago.

I agree, this Charger is just reboxed old technology. I believe in ISDT based technology found in many newer chargers. Like the Hobbymate series D6 and the Speed model. Get used to using a 24volt 400watt PSU (or higher as charger specs dictate). Charging efficiency is most important.
Not a fan of the Spektrum chargers, but they also are ISDT based circuitry/technology. Those older 2 line display chargers like above are SkyRC based and tend to be less precise. They are way overpriced in my opinion. Just reboxed and copied old tech. I have them all.