So your batteries do make contact from head to tail?
You might try loading the batteries, but leave the tail cap off then run a jumper wire from battery negative to the battery tube. This bypasses the tail switch.
You also might try removing the battery tube from the head and make sure there is no glue on top of the driver. The battery tube has to screw down and press on the drivers outer ring. I had a little glue on mine, but not enough to prevent a connection. If they added a bit too much glue it could harden on the driver ring and prevent the battery tube from screwing all the way down and making good contact.
Also make sure the tail cap retaining ring is tight.
Yep cncyana and Jason your suspicion was warranted. I found a pair of protected button-top 18650’s, adding about 6 mm total length and, BINGO, let there be light. I then remembered I had a faulty Folomov travel charger with the magnets (would charge batteries but didn’t work in reverse to charge a device), so I scavanged one of the magnets as a spacer between the too-short, flat-top, 26650s and things work fine now.
All modes and turbo seem to be working fine. Will now check and make sure batteries discharge evenly. If not, I guess maybe I will solder a blob on them.
Boy I like the light. It is a tank. I have lot’s of lights but not a single “thwacker” until now.
I’m still learning when it comes to the max discharge curve. Does it always have to reach 80 degrees to show a max rating?. I’ve seen tests from HKJ that have bad discharge curves which haven’t reached 80 degrees and they’re too high.
I’ve tested 14500 cells and the curves and capacity at that current look terrible without 80 degrees being reached.
EDIT: If I’m wrong them I’ll alter my first comment
No. Magnets having poor resistance is a myth. The material has poor resistance but large diameter and short length means the total resistance is negligible.
This magnet is a 1.53 mm long AWG –1 (yes, negative) solid NdFeB core wire. Despite poor material this conductor has a resistance of about 32 µΩ. This means that with a light pulling 10A the voltage drop is ~0.00032V.
Note that the number doesn’t include contact resistance which is likely higher than that (I would love someone more knowledgable to chime in).
In this case: the adhesive layer is likely an insulator which breaks connection.
Try using the magnet on a cell in a battery charger that measures the internal resistance. You will see a big increase. I’m not sure if this directly effects the performance on a FET driver, I haven’t tried to measure the amp draw difference, but I assume it would.
That, plus the potential to move around if dropped and cause a short makes me not want to ever use them. I’ll just solder blob a cell or get button tops or solder on a button top.
The older cyan and black are good cells (a good choice assuming you can solder blob them for series contact), the new blue 5100mah seem to be questionable. Like always, buy from a reputable store that does not sale fakes.
Here is a repost of my battery tests from a few pages ago.