Modifying the Soshine SC-S2

[old4570]

Id like to thank Member : Tohuwabohu for the mod information .



Resistors go @ R13 and R30 depending on the channel you need to mod ..

Now I used a 2M ohm variable resistor , and I used it on the channel that went way over 4.2v on better cells , and Im not sure if I should be using an ever higher ohm resistor .
Im currently testing with the 2M , and the open voltage is right on 4.2v . whilst the other channel which stops right on the money at 4.2v has an open voltage of 4.21/4.22v ..
The first battery stopped at 4.19v , but Im retesting as I type this ..

Method ..

I put the variable 2M ohm resistor in at R13 set for 0 ohm reading which resulted in an open voltage reading of around 1.35v [ maybe ok for Charging AA's ]
Anyhow , as I tweaked the resistance the voltage went up , I think Im fully set to 2M at the moment , with an open voltage of 4.2v [ waiting to see what termination voltage is with the next battery ]
To get a termination voltage of exactly 4.2v [ to match the other channel ] I might need a slightly higher ohm resistor , I'm not sure whats available after 2M , but I will have a look on ebay after this battery is charged . Originally this channel went to 4.23v , Im not sure what the open voltage was ? If its anything like the other channel , it might have been 4.24/4.25v ..

Charger just finished , and the battery is reading 4.19v/4.2v so its not quite holding 4.2v but rather jumping between 4.2v and 4.19v .. So I need a ever slightly higher ohm resistor .
I will update this when I get a new resistor .

 

[old4570]

Ive just checked all my 2M ohm resistors , there might be one that has slightly more resistance than the others , I will solder it in tomorrow , its a little late now to start soldering [ 11PM ]

 

[pae77]

Wouldn't you rather have it charge to slightly below 4.20 anyway, for better cell longevity? Or maybe you have other chargers for that and want this one set up for when you want to have maximum capacity?

 

[old4570]

Yes , I want this charger to be a 4.2v charger ..
My Ultrafire WF-188 is very sensitive to battery resistance and terminates early with any cell not wanting to go all the way [ With LBJ ] .

I will solder in the other 2M resistor today and see what happens , I might end up buying a 5M ohm variable resistor , but will see what happens .