Hello, I’ve always been using AA and AAA NiMh batteries that I use in my flashlights and then put simply into a charger until the light turns green. I have no experience with lithium batteries, but after surfing this website, I fell in love with 18650 batteries, and the amazing flashlights they can power. I am now thinking of buying maybe some unprotected 18650 (Reverend Jim’s?). Along with the battery and charger (Looking for a decent budget one) , what other devices or tools should I purchase to assure that I will be safe using the 18650’s. Thank you!
a digital multimeter would come in handy to check if charger is charging properly
Do you have a charger that will charge up different sizes of liths already.
I was thinking of a multimeter also, would I be connecting the multimeter to the battery as it was in the charger? Or use the mm to test every once in a while?
No, I do not own any lithium batteries/charger yet. I would prefer a universal lithium charger though.
I hear great things about the Xtar chargers and was going to get one sometime soon...... https://budgetlightforum.com/t/-/3631 And it is compatible with various size cells which is a must for us flashaholics.
i bought a few of the trustfire tr chargers and found the cheapest on ebay vikicompany i think. one was defective and just kept charging to 4.6v. most of them turn green when done then pull battery out to check voltage.
Do not stop, do not pass GO - buy a multimeter.
A multimeter is an essential tool when using 18650s, and should be considered mandatory when using the unprotected variety.
A good habit to develop is checking the cells before and after charging. The goal is to detect a bad cell before it becomes a problem - as in starting a fire or exploding in one's hand.
Some will say that this is an overly cautious approach, but I value my eyesight and all of my appendages more than the 8 seconds per cell it takes to take a MM reading.
These are high-powered energy storage devices and should be treated as such, IMO.
1. DMM
2. Xtar wp2 II or TR001
3. Xtar 2600's or jim's batteries (but they are not protected)
I am new to this as well and would appreciate advice in this area. I value my appendages as well. However, I also ride a motorcycle -- ATGATT. Would simply like info on risks and proper protective strategy.
From what I have read here, the cells from Rev Jim sound like a fantastic deal, provided you either:
A. aren't worried about an extremely 1/???? chance of something failing.
B. Simply know what you are doing with them and the risk drops to basically nothing.
C. You don't buy any because unprotected cells don't belong in a flashlight.
I don't know how to evaluate those positions or exactly how one would use a DMM to learn if a cell is about to fail.
I have an AMM and I check the voltage before and after charging. What does that tell me? Frankly I was just trying to see where the single cell charger I was using was cutting off and if it was consistent. So far I have learned that it is very consistent. Stops at 4v (as close as I can read on my 15v analog scale).
Have a Red Ultrafire AX 18650. I am not certain, but it seems to me like the voltage drops relatively faster on this than my blue 14500. Hard to be sure. What is fair between when trying to judge between a 900mah and 3000 mah? Which one exaggerates more in the first place? How much am I really playing with that XM-L on high? It sure seems to me that I have used my R5 A at least 1/3 as much and the UF blue holds its voltage better. OTOH, the XML-L is fun! With the tin foil in place high is really not an issue. It is possible that I am really using the juice on the 18650.
Serena extended the Xtar deal so I hope to have a couple of those on the way. Should have a few blue trustfire 14500's any day now but it is DX so who knows? More flashlights are on order as well and I would just like to know how to make wiser decisions.
Thank you for your ideas on this.
Wade
We are simply talking about mitigating risk in both cases. ATGATT is a good risk mitigation strategy.
If you keep up with the hobby long enough, something WILL fail. Preparing to deal with it, and more importantly, recognizing imminent failure is the point.
See above. You cannot remove risk, but common sense and a DMM go a long way.
I own some protected, some unprotected cells. Certain drivers have adequate safety cut-off for low voltage, certain protection PCBs cannot handle extreme current draw.
Voltage fluctuations between fresh-off-the-charger and rested state (~1hr later) are one sign.
Higher or lower termination voltage than other cells.
A loss in capacity.
Increasing internal resistance.
Heating up on the charger.
The basic point is to not charge (stress) a damaged cell. An over-charged or over-discharged cell should be discarded. Most cells that see below 3V or over 4.35v should be tossed.
An Analog meter is generally not precise enough to get the voltage measurement down to the 1/100th of a volt that's generally used.
In multi-cell torches, I will not use cells that differ more than 0.03V. This is called matching cells. Charging cells to the same voltage is called balancing them.
I would bet the 3000mAh cell is on the way out, or was never a great cell to begin with. Some of the SONY recycled 18650 cells have been measured at 600mAh or less. For all things equal, the 3000mAh should be 3.33 the capacity of the 900mAh. This is often not the case, as you've noticed.
[quote=how crazy is this] Serena extended the Xtar deal so I hope to have a couple of those on the way. Should have a few blue trustfire 14500's any day now but it is DX so who knows? More flashlights are on order as well and I would just like to know how to make wiser decisions. [/quote]
The XTAR cells should be Sanyo re-wraps of very high quality. If you can stick with Panasonic or Sanyo for the core of your cells, you should be in good shape.
Callie's uses top-shelf Panasonics, as does AW and Redilast. Callie's are safer, IMO, due to the double wrapper - and he hangs out here, too.
It's my pleasure. The forum is here for the exchange of knowledge and ideas, and I'm glad to contribute when possible. I've gleaned much info here, myself.