Nitecore MH12 Charging Issue

Hi all,

just got a nitecore mh12 and am having an issue with charging. No matter how long i leave it to charge through the usb cable it will never go above 4.1v (4 + 1 flashes with the built in charge indicator) and the little blue light never goes out. I tried different cables and usb power sources but seems to make no difference.

anybody have any similar experience?

thanks!

No experience with that light, but some general thoughts.

The built-in measurement system may be off. Check the battery directly with a good multimeter to see what voltage level it is actually charging to.

Even if it is only charging to 4.10V, it is unlikely to affect how bright it is (vs. 4.20V), it would just reduce the total runtime a bit. In fact, some here on CPF only charge their batteries to 4.10 or 4.15 volts in order to extend the battery lifetime.

If the runtime is a concern, just get another good quality 18650 battery (see Electronics forum here for details; get online or maybe even locally at a vape shop; do NOT get any 18650 with "fire" in the name) and keep it charged up. Good to have a spare anyway.

You could also get one of the modern Li-Ion chargers (see that same forum) and charge the battery outside of the light.

Ive noticed that only 2 of my USB charging lights actually charge to 4.20v and those lights are the MH20 and UC35. Everything else cuts off at say 4.17v. I believe some makers design their in light charging systems to say 4.17v as a safety feature or for some other unknown reason. Could be you just got a bum light. I dont see why my MH20 charges to a perfect 4.20v and your light does not. To get past iffy charging systems I bought the excellent VC4 multi chem charger. I now very rarely use the built in USB charging system in my rechargeable lights as the VC4 charges perfectly in half the time....