I just purchased a SolarForce light along with their 18650 "Protected" batteries and Multi-Home and car charger. This is my first foray into Lion batteries. I've been reading up on 18650s and understand that SolarForce are not the best but believe they may be somewhat respectable. If I like the light (which I think I do) I will move onto better batteries and a charger (AWs and Pila?).
The kit I have on hand now has no directions whatsoever. The charger has an indicator for each of two bays. Batteries in, 120V provided, red indicator for about 5 hours.
Does anyone have experience with this battery/charger combination?
Is it timer based? Voltage based? etc. How do I know when the batteries are fully charged?
I had it on the floor in the garage this afternoon, it's on the floor in the basement tonight and will be unpulged before I go to bed with the batteries removed. I don't want to burn the house down due to my current obsession with flashlights.
While I can't comment on the charger's algorithm, I have found the cells to be of very good quality.
The only problem I have run into is one of a brittle wrapper. Only a few cycles in, the wrapper split next to the protection PCB. The other cells are on the way.
This is remedied with some shrink-tubing, or for short-term some Teflon tape.
After using the charger on a variety of cells over a number of weeks, I felt it consistent and safe enough to gift.
Barring a malfunction or short, I think you are more than OK with that combo. Please remember to not leave the cells in a hot car in the sun, and check the voltages before and after charging as part of your Lithium-ion safe handling procedures. They should prevent 99% of explosive failures from occurring by identifying a problem cell before it grenades.
Make sure you have a multimeter available. Always check battery voltage before and after charging. Generally, a Li-ion rechargeable battery is empty at 3.6-3.7v, and full at 4.2v. They should not be charged above 4.2v, so make sure to check after charging before use. I have read many different numbers as far as the dangerous low voltage number, but if you always make sure to charge when you get down around 3.6v you should not be in danger of hurting the cell or yourself. Your chargers LED will most likely turn green when its done charging, but during the first few charges I would not leave it unattended as some cheaper chargers will continue to slowly charge even after the LED turns green. I would watch it and check the voltage periodically during the charging process the first few times.
Thanks for the responses. I charged the batteries today and as expected the LED switched to green when done. Voltage on both cells was 4.26V. Looks like I'm good to go.
4.26 is overcharged. Can you please describe the equipment and technique used to make the measurements ? The info would be helpful in eliminating some variables.
Chicago, once the charger cut off I pulled the batteries (two bay charger, batteries completed charging at different times but I had used one battery a bit before charging). Checked voltage of the batteries on the bench with an OTC DMM, probably within 5 minutes of pulling them off the charger.
I also have a Fluke 73 and 88, I'll check the batteries again today with all three meters to see if there are any inconsistencies.
I found it interesting that during chargine the batteries didn't even become warm to the touch. I had a non-contact pyrometer handy to monitor temp but I noticed no change but touch so never even checked.
Matt
Edit: I just checked both batteries with all three meters.
Battery that was charged and placed in a draw was 4.19V on both Fluke meters, 4.23 on the OTC.
Battery that was charged and placed in the light (which I was playing with last night) was 4.17 on both Flukes, 4.21-4.22 with the OTC. Looks like my OTC may be a bit off but that is why I have the Flukes.
I'm still curious though, is 0.06V really something to be concerned about?
Also, could this charger be used to charge protected 14500 Li-Ion batteries?
The fraction of a volt could be an issue, as it's on the wrong side of fully charged (4.20v)
Overcharging dramatically shortens cell life, as does over-discharging.
Under-charging slightly (~4.15v) will reduce capacity a bit while extending the useful life of most Li-ion cells.
WRT the cell temp, that is normal. Li-ions do not heat up during typical charge currents, unlike NiMh. The cells getting warm would actually be a sign of issues, such as high internal resistance, or imminent failure.
I'm glad that the Fluke told the true story. I would either stick with that one, or make a 'cheat-sheet' to refer to when using the other meter.
I've moved one of the Flukes to the basement, the other one resides in my trunk for daily use. I stuck the OTC in the garage for less critical applications.
Next time I charge the batteries I'll check before and after voltage to keep an eye on it.
"Always check battery voltage before and after charging. Generally, a Li-ion rechargeable battery is empty at 3.6-3.7v, and full at 4.2v. They should not be charged above 4.2v, so make sure to check after charging before use." Thanks for this wonderful insight I'm not that good in battery management. I personally afraid to do task like auto handling and monitoring. Vehicle batteries are important for keeping your car working. Understanding the particulars of your battery can help keep your vehicle in top operating shape. Source for this article: The basics of the battery that runs your vehicle.
I'm thinking about getting this combo with a new P1 and was wondering, now that you've had it for a while, how you feel about it. Do you still think it a good value? Would you do it again? Do you plug in and forget, or do you check it every time?