Hadn’t bought a decent flashlight in 10+ years, so after finding the FW4A figured I’d give it a shot. So 2 FW4A, 16 batteries, and 2 Nitecore UM4 chargers, planning on giving one complete setup as a gift to someone. I first just ordered (8) Imren Gold 3500mAH 30A/15A, but started seeing bad reviews, so also ordered (8)Samsung 30Q 3000mAh 30A/15A. The lights took 10 days coming from China, so had all the batteries charged. When they arrived today, I checked them out, learned the OS etc., then decided if I was giving someone these batteries as a gift, I wouldn’t want them burning their house down or blowing up in their pocket. Thought I better do a stress test on them and see hope everything survived. Well, everything went well I think. I know this light has been out a while, and there’s probably all kinds of info out already, but figured maybe someone could use this info. Something to thank you guys for the good info, and what I hope will be a great light for me. It is pretty cool compared to what I was buying 10-15 years ago.
Since I had 2 FW4A, each configured exactly the same, I took one of each brand battery and stated them on turbo at the same time. Stood them on their tail, and just let the lights step down when they got hot. Apparently the FW4A will give as much light as it can while staying under the ceiling temp you set. I had them both set to 55c, and they both stepped down to what I think is the high (130) setting after 17 seconds. I just let them sit there and cook until I saw them step down again, which must have been the low voltage protection kicking in. I don’t have a thermometer, but I do think they stayed right around 55c. I could hold them in my had, but don’t think I’d want them in my pocket as hot as they were. I kept checking them and they stayed hot the whole time until stepping down for low voltage. Is this test result consistent with what you guys have been seeing?
Please let me know if you guys think these Imren 18650 would be unsafe to keep using in this light. I guess just because they survived one torture test doesn’t mean they won’t blow up on the 23rd charge. Should the Samsung hold up better down the road?
Imren Gold 3500mAh
Advertised Continuous Discharge Rating: 15A (found to be 10A by reviewers)
Advertised Pulse Discharge Rating: 30A
Samsung 30Q 3000mAh
Advertised Continuous Discharge Rating: 15A
Advertised Pulse Discharge Rating: 25A
Both calibrated at 25c
Both ceiling temp set to 55c
Both started at 25c
Runtime until automatic temperature stepdown from turbo/150 (max) to maybe 130?
Imren - 17 seconds
Samsung - 17 seconds
Runtime until low voltage protection stepdown
Imren - 2hrs 55min putting out 2.94v
Samsung - 2hrs 18min putting out 2.92v