Thanks for the reply, I really appreciate it.
I've been playing around a bit tonight and searching for a solution.
I tried installing an old hot plate, one coil of 40ohm on the hot wire of ac, it fluctuated the output.
Cancelled that experiment.
I then plugged one charger in, took it out quickly and plugged in a second charger.
After a few attempts I got the "good" charger going again. Temp of case is at a steady 40C and slowly increasing normally.
The usual fault condition of the charger occurred when I measured the voltage of the unplugged charger.
Meaning it slowly decreased to zero, in a total span of under a minute.
I noticed too that when I plugged in a charger, it would increase the battery voltage by 0.10V, but would never chooch no juice. Unplug the charger, charger goes to 0V.
Thank you spec for your input, as I said I really appreciate it. This is the first time I have heard/read about the low cost battery control boards, I will have a quick look at them right now. I thought perhaps you mean a BMS (Battery Management System) but I have not been using them as these cells stay stable as long as I do not abuse them, they are always well within balance spec. When I do need to balance, I have a wimpy and slow 50W RC charger that can do 6S but only 1P at a time. So you can imagine how slow a process it can be. I bulk charge them to 4.10V then apply balance charge, but usually I manually get the ones way out of line exactly, but this method happens infrequently. I open them up every few months, they are stable. I just dont drain them too much to get out of wack.
I typed in "battery controller boards" into ebay search.
Titles such as "XY-L10A Lithium Battery Charge Controller Protection Board 6-60V LCD Display" come up
Reading the description, I do not have a problem with the end voltage, 21.00V is my max, chargers only go to 19.50-19.75V.
I built my pack to achieve the correct C-rate for charging. 5S10P put in series with another 5S10P = 10S10P giving my 21V 30Ah x2 in series = 42V 30Ah (new)
These chargers are 6.7A on 21V 30Ah. Its equal to a ~14A charge on a 42V 30Ah.
My old Mean Well's were pumping out 15A on 10S10P, but were much larger and heavier.
I know now I am rambling, it just baffles me is all. Learning all this new jargon, but yet its fascinating how all the lego pieces work to do what it does.
I will buy a few caps tomorrow, plus a range of NTC's
I assume this cap just slows the current down, by storing the charge up so the charger has time to compensate.
I was also thinking of using a diode/one way valve so the current from the battery doesnt trip up the charger when I plug it in.
Thanks again. I will report back tomorrow as its late night here now.
1mF (1000uF), or larger, capacitor across the output of the laptop PSU. The voltage rating of the capacitor should be 35V or higher.