Because for the iCharger X8, power input is 9v to 49v. Can it be used to do a single cell? Certainly anyone wanting to do more than a single cell at a time (thus justifying spending $99 + "whatever" versus $55) will need more than any old power supply. Especially if you want the 30 amp capability. For about $200 I can get a Riden, much more versatile, although only capable of 24 amps. The Riden will also allow you to set tail current, so is likely to do a much better job when top balancing. I've looked at the iCharger X8, the only reason I didn't get one was the inability to find a suitable power supply. Nice charger, but requires a power supply to be useful, or just buy the power supply.
I've used this:
www.circuitspecialists.com
And really like my Ridens:
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But most people would be better off buying a cheap (~$55) power supply like this:
Or just add an active balancer and use your solar charge controller:
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I have all of the above, so my question about what 1100 watt power supply you used still stands. I'd like to purchase one and try it out.