SR90 - charging

[Steve'O]

Hi there,

I charged my sr90 today, it took 7 hours to charge from a resting voltage of 7.35v. The batt pack state of charge indicator still showed 1 green light before charging.
The manual states it can take up to 12 hours on the first full charge.

Previous to this, I have only charged it a couple of times, from roughly a 60-80% capacity.

I kept my eye on it most of the time and disconnected as the light changed from red to green, then checked the resting volts again and got a reading of only 8.00v .

I was expecting it to read from 8.2v to 8.4v

The dmm I use is a Rapitest DM10, it did not cost much, but some months back I checked it's accuracy along side a friends costing 4 times more and got the same readings on a 3.7v li-ion, so I think the dmm is ok.

Any idea's from the experts, or have any other sr90 owners out there noted the voltage of their batt packs straight off the charger ?

Thanks
Steve'o

 

[Steve'O]

No user's of this light out there who tests the output voltage after charge ? :thinking:

Anyway, my feeling is that maybe the battery manufacturer and Olight are playing on the safe side with this one, which is not a bad thing with 6 Li-ion cells. The way they machined the handle reminds me of a grenade.

 

[billcushman]

The charger on my SR90 is Model:LYD250840300. It is slightly different from the one pictured on early units. It appears to be a constant voltage charger with a maximum current of 3.0 amps. Its open circuit voltage is 8.422 VDC with ripple of 0.0230 VAC. The charge light changes from red to green at 8.072 VDC. When the light changes from red to green the charge current measures about 207 mA.

If you leave the charger connected for several additional hours the voltage will continue to rise (not over open circuit voltage) and the current will fall. It will usually require several more hours for the current to drop below 50 mA. At that time the voltage measures about 8.15 VDC. The lowest value I observed on current was about 29 mA and the highest voltage was 8.163 VDC. I did not continue the test more than a few hours after the light turned green.

For best battery life recharge the battery frequently and do not deeply discharge. Lower charge termination voltage will increase cycle life. Never leave the charger connected more than a few hours after the light turns green because the charger does not appear to terminate.

 

[Steve'O]

Thanks very much for that info Bill, you obviously know what you are talking about.

My knowledge on electronics is very basic, but I am well aware of the dangerous side of things from reading up on this great forum.

I checked the chargers model# and it is the same as yours.

Cheers :thumbsup:

 

[RCLumens]

Thanks for the info StevO & Bill - can't believe there's nit more infor on charging these things on here. I'm late to the game - but starting to play around with some of these SR lights now...