Hi Guys
I have no experience in the use of torches and I live in Spain, I hope the translator does its job.
I received the Sofirn Q8 Plus yesterday, question about charging/discharging.
There is something I don’t understand about this torch. Yesterday I received it, I put it on charge for several hours, until the charge indicator instead of blinking, it was lit but steady. It was very late and I went to sleep.
I haven’t used it yet, I didn’t turn it on once. Now, today in the morning, I happened to put it back to charge on the computer
and the charge indicator started flashing again, as if it hadn’t been fully charged yesterday. I plugged the charging cable back in until it was steady again, which in theory would indicate a full charge. I immediately disconnect the cable, reconnect it to the computer and it has been charging for hours with the light flashing! How can this be? If I had used it, it’s fine that it has been charging for a while because there are three 21700 batteries, but by just unplugging it, without using it, it takes so long to recharge? Is this normal or is there a problem with the charging? The batteries are the Sofirn ones that are already supplied with the torch.
Thank you.
Regards
All of my chargers will charge a full battery for a short while (5 seconds to some minutes) before the charger recognises the battery is full.
Do, however, check the cells are not getting hot while charging, this would indicate a problem.
If you have a digital multimeter, fully charge the cells and measure the voltage of each of them.
Leave the cells out of the light over night, then check the voltage in the morning. They should all read approximately the same as they did before, maybe dropping 0.05V or something. A bigger voltage drop indicates a problem.
I had the same problem with my Sofirn sp33s. I would fully charge it, disconnect and reconnect it. It would then continue to charge. I contacted Sofirn about it, and they said it was a design flaw. From the little testing I have done, it doesn’t go above 4.2 volt (again, very litte testing). I assume you should be fine. When it says it is done charging, it should be. Even if it countiues to blink if you reconnect it.
Hello to all,
Thank you very much for the answers to my questions.
Well for one thing, I checked the batteries (as gravelmonkey suggested) and they don’t heat up. Yesterday, after 7 hours and 15 minutes of extra charging, it finally stopped flashing, indicating full charge. Now, the day before yesterday it was a minimum of 10 hours, which added to yesterday’s 7+ hours, gives about 17 hours. Perhaps an important detail is that yesterday I tightened the thread more tightly.
But as LightThrower told me, the torch seems to have charged correctly, I tested it in several modes and it works very well.
I’m going to do two things: buy a multimeter and find out for sure.
And in the meantime I’m going to leave it charged for 8 hours before each time I use it.
When I get the multimeter, if it doesn’t charge properly, I’ll let you know what I think.
Regards,
Max.
This is not a design flaw, it is how Lithium batteries work (and damaging the cells if you keep doing it repeatedly).
Lithium cells are charged at a constant current first, constant voltage later until full at 4.2 V. If being forced at 4.2 V for an extended amount of time, the cells take damage. So the chargers have a shut-off limit of usually 50-100mA - the moment the charge current drops beneath this threshold it will be deemed as “full” and charging is terminated.
After this, the cell voltage will drop by itself to something around 4.1 to 4.15 V. If you plug the charger in again now, it will see the battery as not full (as it is not at 4.2V) and force it up to 4.2V again, before terminating again. This is not a usable amount of energy, and does not make the cell any more full, it just shortens lifespan and has no advantage.
Some more expensive and advanced chargers may recognize this, and refuse to charge a cell >4.1 V, but most simpler chips and even dedicated chargers to not.
The batteries are full when the light terminates the charge first. Every subsequent “charge” is just an artifact of how LiIon cells and chargers work, and not specific to this light, or an indication of any problem.
This is fairly weird - it reads to me as if you somehow managed to disable the shutoff threshold for the charger through unplugging and replugging somehow. This should not happen, and will seriously shorten the lifespan of batteries if it happens repeatedly, as it means the light is forcing the cells to sit at 4.2 V for hours and hours.
Moral of the story really is: if you’re playing with loose cells (like 99.9% of us), get a voltmeter and understandstand what the readings mean, maybe an hour of reading and you’re golden.
Hi Guys,
I order the voltmeter from AE tomorrow.
I have an external charger, not the one built into the torch. I think the solution–if I understood your input correctly–is to charge the batteries in that external charger, up to the right voltage, and use the torch until it tells me it needs recharging. I’ve also been told to clean all the battery contacts and springs. And to try connecting with a suitable mains adapter, for which I have an adapter from an old Iphone 6. When I receive the voltmeter and do my tests, I will let you know how the story goes.
Greetings to all and thanks again.
