Nitecore MH12 Pro - battery issue?

I’ve noticed if I run my MH12 Pro on High it gets down to a single dot after less than an hour. I tried calibrating by running it flat and charging again but it’s the same. Wondering if the cell could be bad? It’s meant to have 4h 30m runtime on high so being at 0-25% power after less than an hour seems wrong.

Did some more testing.

This chart: https://www.candlepowerforums.com/attachments/nfsndmog_o-jpg.48685/

suggests that high mode should last for around 3h without kicking down, but mine kicked down to low after under 2h.

Kicked down to moonlight mode at 2h 30 of total runtime, so definitely something not right.

If it was me I would try another battery.

Forgot to ask how are you charging the battery and what is the voltage when it comes off the charger?

Don’t have another battery to try. It charges in the light via usb-c, haven’t checked the voltage.

I’m contacted nitecore’s uk distributor where I bought it and waiting on a response from the manufacturer. I suspect it’s a duff cell

It’s important to know what the voltage is at the end of the charge cycle. It could be that the charger is grossly undercharging the battery.

Do you know anyone that you can borrow a volt meter from?

Battery voltage after a “full” charge is 4.02V so yeah it seems the torch may not be charging it properly.

4.02v is roughly 80% charged, could be more or less depending upon the battery. So I’m not surprised that the light is kicking down from high earlier than expected.

If you don’t have a charger you should get one. You can get a decent one for $20 or less that will charge the battery to 4.2v and keep the light in high mode longer than what you’re getting now. You can even get something like a Liikala charger for less than $10.

One can argue that the light is defective since the internal charger is only charging the battery to 4.0v but Nitecore could say it’s for safety reasons.

The retailer (nitecore UK) said send it back so I did that today. Also agreed with me that the charged voltage should be 4.2V

Glad to hear that it worked out for you.

Zeroair result.

Roma58
Nitecore MH12 Pro Review - 3300 lumens, UHi LED - LED Flashlights – General Info / 21700 Flashlights - BudgetLightForum.com

Yeah mine was definitely faulty

Nitecore UK got back to me, apparently the manufacturer said because I was cycling with it, the air going over the light could cause enough of a cooling effect that it would draw more power and so runtime would be affected. As to whether it would be affected to this degree, don’t know.

They said it would take days to run through testing scenarios to determine if it really was at fault but offered me a refund as an alternative so I took that as I need a working light. Ordered Fenix PD36R Pro again, I’ve never had an issue with Fenix lights.