Thank you for your thoughts. What batteries are using with yours? All areas you covered above were checked together with switch etc. and all function when plugged in USB charger. Everything leads me back to the battery or power source used. Contacts are good especially with the double copper spring in the tail cap. Frankly, I am baffled that’s why ask about what everyone is using as a battery source; eg. specific to brand, size, power outputs, etc. I just don’t know what else to check???
I’m not very sure what is the “over-discharge current” cut-off threshold for the protected Keeppower 26650. However if you use that protected 26650 on the FT03 XHP50.2, I’m pretty sure the overdischarge current will be triggered (I’ve tested the FT03 XHP50.2 uses up to around 14 Amps on a good high-drain 26650, probably a bit less on a higher-resistance or protected 26650 — but it’s still possible to trigger the overdischarge current protection).
On the FT03 with SST40, I think it should be less likely to trigger the overcurrent protection (I tested around 8-9 Amps tailcap current on a high drain 26650 battery), my guess is that the protection circuit of a Keeppower 26650 would be higher than that (maybe 10 Amps??)
~
Wait, I mis-read your post, you mentioned not even having power signal… so it could be the battery is not making proper contact with the body tube (head or tailspring section?)
Is there a driver swap you can do that has a v booster?
Thanks again. Double checked that I do in fact have the XHP50.2 so your conclusions may be the issue alright. I have another 26650 unprotected coming from Nitecore NI26650A is a 4200mAh 40A IMR 26650 high drain rechargeable battery. The 4200mAh capacity offers a long runtime with a high maximum pulse amperage of 40A and max continuous discharge of 21A. Designed with a flat-top connection, this battery contains a reliable Panasonic core. I’m hoping this will fit the bill in providing the kind of specs this particular model requires.
For being a ‘newbie’ on this site I am sure delighted at the early responses and continue to look forward to any other ideas and/or other battery types that can be provided. Those of you FT03 owners out there with this particular model, I would also appreciate hearing on specific battery brands (ratings, etc.) that you have been successful in use with your torch.
But, didn’t you already try an unprotected cell? There would be no current trip if you use an unprotected cell, so that would rule out the Keeppower’s protection issue.
Does the Ft03 have low voltage cut-off? It’s a necessity IMO if you’re using unprotected batteries. Sorry if this has been previously answered.
The manual says it does but I haven’t tested it.
OK