Nitecore LR50 Powerbank function no longer working

Flying_Luminosity · 2019-12-10T09:44:12.000Z

Yesterday I noticed that the blue charging light of my LR50 lantern had come on, or possibly not turned off again after I had previously charged it via USB. The blue LED now always stays on, regardless of whether the lantern is turned on or off, even after removing and reinserting the batteries.

One of the things that I tried was to plug some cables into the USB-A socket. When I plugged in an LED cable I realised that only the end of it was very dimly lit, so it seems that the current coming out of the port must be very small - in fact it’s not even enough to charge the antique phone that I’m currently using.

Does anyone know what might be causing this, and if it can be fixed?

Flying_Luminosity · 2019-12-10T10:07:12.000Z

I just remembered how I recently found out that the lantern doesn’t have any LVP. When I tried to increase the brightness it stayed at the Low setting, so I pulled out the batteries and found out that they had discharged to 2.75V and 2.85V. Could this have damaged the electronics? The batteries themselves seem fine, after I charged them very slowly with my BT-C3100.

Dutcheee · 2019-12-10T10:51:02.000Z

I think you’ll be fine. The longer they have a low discharge, the worse they seem to get. Do a capacity test on your Opus, if they’re still at their original capacity I wouldn’t worry too much.

2.8V is around the low end, but not too deeply discharged I think.

I don’t see how low batteries could have damaged the Nitecore. Did you try different batteries?

Flying_Luminosity · 2019-12-10T11:42:21.000Z

Dutcheee:

I think you’ll be fine. The longer they have a low discharge, the worse they seem to get. Do a capacity test on your Opus, if they’re still at their original capacity I wouldn’t worry too much.

2.8V is around the low end, but not too deeply discharged I think.

I don’t see how low batteries could have damaged the Nitecore. Did you try different batteries?

I won’t have any other button top 18650s until I receive my LT1. But your’re probably right that it’s unlikely the problem has anything to do with the batteries. They supply enough current to power all 9 LEDs in High mode, and I usually just use one side (3 LEDs) in Low or Medium. I’ll put them through a discharge test anyway.

I also plugged an electronic load into the USB socket, and the current coming out of it isn’t enough to power the display.

Big_Sam · 2019-12-10T17:27:48.000Z

I would guess the power bank chip either has a low voltage cut off or is matched up with a DW01 protection chip and probably independent of the lantern circuit.

Flying_Luminosity · 2019-12-10T19:39:30.000Z

Big_Sam:

I would guess the power bank chip either has a low voltage cut off or is matched up with a DW01 protection chip and probably independent of the lantern circuit.

What does that mean? I’ve used the powerbank feature a number of imes before to charge my phone, and the behaviour that I’ve described is only recent.

It seems that the transparent part (battery holder & LEDs) is glued to the bottom of the light that contains the MCPCB, so I’m thinking about applying a heat gun to try and open it up.

nydude · 2019-12-10T22:27:27.000Z

I have three nitecore products that all seem to have some electrical problem or another. None have been used very much. Really want to like this company because of the cool products but it’s getting harder.

Big_Sam · 2019-12-10T23:06:38.000Z

I’ve been looking at the circuit boards on the tear down review here but can’t see a dedicated power bank chip, so it might be done through the main MCU

https://www.bmengineer.com/2019/06/new-nitecore-lr50.html

Big_Sam · 2019-12-10T23:08:10.000Z

I can’t seem to edit that post, the review shows how to get it apart as well. Hidden screws.

Flying_Luminosity · 2019-12-10T23:48:08.000Z

nydude:

I have three nitecore products that all seem to have some electrical problem or another. None have been used very much. Really want to like this company because of the cool products but it’s getting harder.

Out of several that I’ve owned, this is actually the first Nitecore light that I really like, apart from maybe a number of TIPs that I bought in the past to give away as presents. I really hope that there is a way to get the powerbank function to work again (and to get rid of that continuous blue light), as it has come in handy a number of times.

Big_Sam:

I’ve been looking at the circuit boards on the tear down review here but can’t see a dedicated power bank chip, so it might be done through the main MCU

https://www.bmengineer.com/2019/06/new-nitecore-lr50.html

Thanks, I’ll have a look at it in the daytime. Was checking ZeroAir’s review earlier on for instructions on how to take it apart, but it wasn’t mentioned.

EDIT: I forgot to mention that there’s a high pitched whining noise coming from where the MCPCB is if I plug in a USB cable, not sure if that means anything to anyone.