Advice needed on Vtoman flashspeed 1500 that goes from 20-25% to fully discharged.
Cuban here in the middle of an energetic crisis. My Vtoman flashspeed started bugging like this (depletes completely when battery displays it's at 20-25% charge). In Cuba these powerstations are expensive, bought it a year ago, and want to make it last for as much as possible, so any advice it's greatly appreciated.
Possible issues:
-T > 30°C up to 39°C (I know this affects cell durability, like it halfs its life for every 5°C increase over 30). Any 3rd world advice to compensate when facing daily 18-24hs power outs, so hard to keep in a cool environment. I turn on an electric fan when charging it, but don't know how much it helps. Is it too much if I to put frozen bottles next to my power station just to lower the surrounding temp? JK... Or am I? I'm despaired for solutions...
-The inner fan turns off at around 80% charge when charging (never happened before, is it normal?).
-Dad keeps charging it up to 100% (even though I tell him to keep it up to 90%). Understandable when charging the backup battery (only charges after power station reaches 100%), but risky as a daily choice when extra battery is charged.
-We have a 400W solar panel we use when necessary (is it better to charge the power station at regular temp >30°C at 400W for 4hs, or charge it at 1500W for 1-2hs with an electric fan at ~30C or AC at 24°C?)
-Voltage (we can't really regulate voltage, should I get a multimeter to be safe although it won't help due to voltage alterations when he power just randomly goes off?).
-It's a 12 caliber cable wired outlet (20A, 120V, 2400W) good enough to charge my 1500W power station without issues? Would it be too risky to push it a little closer with a 14 caliber cable wired outlet (15A, 120V, 1800W)? I think I need a 20% extra to make sure there are not issues, so 1800 should cut it or does practice differ from theory? We have AC on the bedrooms (can charge with regulated temp) but just want to be sure it won't overload/burn the wiring on my apartment...
Sorry if my questions seem dumb, I'm new to this and just do basic DIY electricity work (which means I try my luck, and each time it works I do a little victory dance and praise the electricity gods...).
Also, if you don't know or don't have time to answer, do you recommend any good lecture to deeply understand this? Thank you.