Nitecore MH20 UI seems broken? Hoping first battery charge will fix it.. Anyone else?

So I ordered a Nitecore MH20 and it arrived 3 days ago. I've been using it very frequently since, especially on turbo mode. I've probably had it on high/turbo for over an hour without a battery charge, ever. The 3400mah battery from Nitecore (EASTSHINE dealer) came charged according to the blinking light battery gauge meter around 80% or so it seemed... 3 blinks... 6 blinks.. (not sure how the second flash amount exceeded 4... (.400mah) perhaps I've been reading the meter wrong. However after such prolonged usage without ever charging it, last night before using it for 45+ minutes on turbo/high, it showed 3 blinks... 4 blinks. Now this morning it shows 3 blinks... 1 blink. Am i to really believe it has 3.1v out of 3.4v left on the battery??

Also, what REALLY concerns me is that the UI totally changed now. I only dropped it once last night from about 6ft in my front yard on dirt/grass, and even after it fell, it keeped working just fine. It would go through the 5 modes, moonlight->turbo perfectly and everything was cool. Until this morning after more usage it seems to have broken. When I full click it on, it only blinks once and as soon as I let go of the switch it turns off. I can play with it to get it to go into moonlight mode, but it will not 'half click' and step up through the modes. Only Moonlight jumps to turbo instantly. Strobe keeps coming on accidently at times, and full clicks don't always turn the flashlight on. Its like every other or every third works. Is my battery just totally dead? (Its charging now) I would think the UI would remain the same with a low battery... or is it broken?

Any words of encouragement will certainly put my mind at ease for the next 3-5 hours while it charges. Thanks!

Do you have a digital voltmeter? Read the voltage directly off the cell with that and see it it agrees with the blink rate. 3 + 1 blinks on the light should give you a 3.1 volt meter reading.

Mine charges up and ceases charge at 4.2 volts by the meter. The gives me 4 + 2 blinks at that point. I have a meter on the USB line and usually unplug the charger when the amps fall to about 0.10. That gives me 4.1 volts on the battery and I'm fine with that.

The situation when your would not ramp up from moon just sounds like the battery was too low too support the brighter settings. I have noticed there is a point where it will no longer ramp into high. Then with more use it will no longer ramp into medium. Time to recharge.

Battery was shipped with storage charge.
It needs to be charged, 3.6 is getting low enough IMO, never mind 3.1.
That is near cut off voltage and cell should protect itself from this soon and go 0.0v.
4.2v is a full charge.

The blinking power reading tells you the voltage. Voltage has nothing at all to do with mAh. A fully charged battery will be 4.2 volts. 3.6-3.7 is storage voltage and what most batteries are shipped at. You should have charged it to begin with.

As for the UI behavior, I'm not sure I fully understand your problem, and I don't have much experience with this particular light, but it's normal for a light to not want to hit the higher outputs when the voltage drops.

By the way, you should charge your light more. Frequent, small top offs are better for the longevity of the battery than letting it go all the way to 3.1 volts and back. Treat it like your cell phone and charge it frequently. You never know when you're going to wish that you'd charged it.

Thank you all for your replies and words of comfort.

Update: After a full charge (I think, 5-6 hours in) the UI is back to its full functionality! @Jim thank you for explaining voltage and mAh for me. I was certainly clueless in this category. The blinking makes a whole lot more sense now on the built in battery gauge. I was expecting it to go from 3 flashes -> 4 flashes (3.4mAh which i thought equalled 3.4volts) down to 0 flashes->1flash for 0.1mAh or .1v left of charge. Don't I feel dumb.. :laughing: Humbling little thread this is for me haha.

Also, I found something interesting. I wonder if everyone else's 'half click' on their MH20 is the same as mine. It seems you can push the 'half click' on ever so slightly softer than is required to activate moonlight mode, and nothing will happen at all, yet it still 'feels' like you're half-clicking. Has anyone else noticed this? Or is my product defective? I find myself occasionally trying to enter moonlight mode from off, and nothing happens because I need to apply JUST BARELY more pressure in my half click for it to work. Perhaps my half-click isn't perfectly centred on the button or something of that sort... or is this a prevention from accidental activation feature?

Just tried with mine. If I feel the button do the half-click, it registers it. I can't get it to do what you're describing. This doesn't necessarily mean that something is wrong with your light, it just needs a little bit of extra pressure.

Also, to expand on voltage, 3.1 volts is an almost completely empty battery. Different cells will have slightly different minimum voltages, but you really shouldn't make a habit of taking your battery that low. I usually top off my batteries when they're at 3.8-3.9 volts.

JimTokle said:

Just tried with mine. If I feel the button do the half-click, it registers it. I can't get it to do what you're describing. This doesn't necessarily mean that something is wrong with your light, it just needs a little bit of extra pressure.

Also, to expand on voltage, 3.1 volts is an almost completely empty battery. Different cells will have slightly different minimum voltages, but you really shouldn't make a habit of taking your battery that low. I usually top off my batteries when they're at 3.8-3.9 volts.

Click to expand...

For what reason(s) should I avoid draining batteries entirely before recharging them? I would think since a battery claims to have around 500 charges in it, that I should use each full charge very efficiently. Explanation please!

OnlyownEnergizer250lumen said:

For what reason(s) should I avoid draining batteries entirely before recharging them? I would think since a battery claims to have around 500 charges in it, that I should use each full charge very efficiently. Explanation please!

Click to expand...

It doesn't quite work like that. If you discharge it 20% and then top it off, you'd have to do that five times to equal one of the cycles that your battery is rated for. Someone else can probably explain the technical details better than I can, but li-ion batteries don't like to be fully cycled. They like small, frequent top offs.

You're not hurting the battery by keeping it charged. Do you really want to take a chance on your light being dead when you really need it? Would you leave the house with your cell phone almost dead? Modern battery technology gives us the ability to always have a fully charged light, and there have been times that I've actually needed that full battery. Not to mention that a fully charged light is brighter

Okay, makes sense, however isn't it bad to frequently 'over-charge' it even though its protected? For example, say its 3.6v left out of the 4.2v (or whatever max 18650 3400mAh volts are) and I'm going to go to sleep for 7 hours, but it would only take 1-2 hours for it to fully charge... do I plug it in? I know its protected battery and its supposed to cut off the charge.. but isn't it better to unplug it immediately when it reaches full capacity?

OnlyownEnergizer250lumen said:

Okay, makes sense, however isn't it bad to frequently 'over-charge' it even though its protected? For example, say its 3.6v left out of the 4.2v (or whatever max 18650 3400mAh volts are) and I'm going to go to sleep for 7 hours, but it would only take 1-2 hours for it to fully charge... do I plug it in? I know its protected battery and its supposed to cut off the charge.. but isn't it better to unplug it immediately when it reaches full capacity?

Click to expand...

The battery and the light both have features to keep from overcharging. I don't think the MH20 even charges it to 4.2. The meter on mine always shows it at 4.1 when it's done charging. A charger that overcharges would be flat out dangerous. I plug my MH20 and my cell phone in every morning when I go to bed. It's wonderful starting the evening with a fully charged light. You're not going to hurt the battery, it will still last a few good years, and a new one is like $12. Keep it charged and enjoy it. You only get the maximum output at higher voltages anyways.

JimTokle said:

It doesn't quite work like that. If you discharge it 20% and then top it off, you'd have to do that five times to equal one of the cycles that your battery is rated for. Someone else can probably explain the technical details better than I can, but li-ion batteries don't like to be fully cycled. They like small, frequent top offs.

Click to expand...

From what I've seen it's the reverse - frequent top-off charging wears batts more than deep discharge cycling. Technically, the cell will last longest if can you minimize: the peak charge voltage, average voltage, depth of discharge, and temperature.

That said, these batts are cheap and easy to replace - I also typically just recharge at ~ 3.8V (~60% discharged), which for me is a balance between enough reserve power (~40%), and least PITA/trips to the battery charger. You really don't want to run the cell empty as you risk the light/or batt. protection circuit shutting the light off, or over-discharging the cell and destabilizing the chemistry.

Source: Batt. Univ. and this Military Study on Cycling Habits.

reppans said:

From what I've seen it's the reverse - frequent top-off charging wears batts more than deep discharge cycling. Technically, the cell will last longest if can you minimize: the peak charge voltage, average voltage, depth of discharge, and temperature.

That said, these batts are cheap and easy to replace - I also typically just recharge at ~ 3.8V (~60% discharged), which for me is a balance between enough reserve power (~40%), and least PITA/trips to the battery charger. You really don't want to run the cell empty as you risk the light/or batt. protection circuit shutting the light off, or over-discharging the cell and destabilizing the chemistry.

Source: Batt. Univ. and this Military Study on Cycling Habits.

Click to expand...

My MH20 doesn't even fully top it off. I know that it's bad to frequently, fully top the battery off. I'm bad at explaining things, but that's where I was going with that. Either my MH20 is defective, or it was designed with frequent charging in mind. My point was that it won't hurt at all to plug the MH20 in whenever OP gets a chance. Even if it's not the best for the battery, it's still going to last for years and is easily replaceable for $12. There's no need to worry about min/maxing every detail of its life.

I'd think less damage with small top ups versus full drains.
Drain it now and then, but rarely.
Jmtc an IMO.
My wife can kill a laptop pack in year going full to empty, three years if she tops up, go figure.

My MH20 charges my Fenix 3400 to 4.22. I'm OK with that for the record.