Cheapy two bay wall wart charger that came with my cheapy light/batteries question

[Hot Brass]

Hi:
I just received my Ultrafire C8 light which came with two 18650 "protected"batteries and one cheapy($3.00) two bay wall-wart style charger. Of course,no manual with the charger!! Can I charge one battery at a time,or do I need to have two charging together?.If so,do the batteries have to be close in voltage...let's say one is 3.7 and the other is 3.9 volts....will the charger shut-off when the 'fuller' cell reaches 4.2 volts,leaving the lower filled cell needing more charging?
I also have a XTAR WP2 II charger that I can use instead if this one is not too safe to use....just thought I would like to try it,(the cheap one,plugged in outside!).I will keep an eye on it while charging and check frequently with digital voltage meter for over-charging!Thanks,Hot Brass

 

[Shadowww]

$3 chargers are generally utter crap, made of cheap components, with bad build quality etc etc.
Your WP2 II is very good charger, just use it. You don't want to risk your health, in case that thing explodes with batteries in it.

 

[Norm]

$3 chargers are generally utter crap, made of cheap components, with bad build quality etc etc.
Your WP2 II is very good charger, just use it. You don't want to risk your health, in case that thing explodes with batteries in it.

And generally charge both cells in parallel.

Norm

 

[Hot Brass]

And generally charge both cells in parallel.

Norm

Thanks,but not sure what that means ^....do I need two cells in order to charge properly?Thanks,Hot Brass

 

[127.0.0.1]

Thanks,but not sure what that means ^....do I need two cells in order to charge properly?Thanks,Hot Brass

parallel means you can charge 1 or 2 at a time, but it cannot read the difference between cells, meaning
it can overcharge one or undercharge one [because it can only read the average charge of both]

or it is really a dumb charger and based on a fixed time. a lot of cheap chargers just 'charge for 4 hours' with zero
intelligence. usually these are nimh chargers only

your WP2 is the thing to use, it has 2 independent charge circuits. I definitely know this as my wp2 always
charges bay 1 to 4.21 volts and bay 2 is always 4.19 before cutoff. these variances are acceptable, but also proof
that the WP2 has 2 independent circuits

 

[Hot Brass]

parallel means you can charge 1 or 2 at a time, but it cannot read the difference between cells, meaning
it can overcharge one or undercharge one [because it can only read the average charge of both]

or it is really a dumb charger and based on a fixed time. a lot of cheap chargers just 'charge for 4 hours' with zero
intelligence. usually these are nimh chargers only

your WP2 is the thing to use, it has 2 independent charge circuits. I definitely know this as my wp2 always
charges bay 1 to 4.21 volts and bay 2 is always 4.19 before cutoff. these variances are acceptable, but also proof
that the WP2 has 2 independent circuits

Thanks! Both these batteries were at 3.81,3.83 volts when I received them,so should I run them down to around 3.7 volts and then re-charge,or just charge em up now? Thanks,Hot Brass

 

[Shadowww]

Thanks! Both these batteries were at 3.81,3.83 volts when I received them,so should I run them down to around 3.7 volts and then re-charge,or just charge em up now? Thanks,Hot Brass

You can charge them up right now, Li-Ion's don't mind being topped up (unlike NiMH's).

 

[Hot Brass]

You can charge them up right now, Li-Ion's don't mind being topped up (unlike NiMH's).

Thanks! Hot Brass

 

[Norm]

parallel means you can charge 1 or 2 at a time, but it cannot read the difference between cells, meaning
it can overcharge one or undercharge one [because it can only read the average charge of both]

The above statement is confusing, check out the links here in this search.

Norm