Dead quick tip - no charge

Just watching this now, Im a bit behind on patreon! Really geat tip

I had a similar issue with an old wireless phone set years ago, but it had an NiCd battery, but "kickstarting" it by putting a bit of charge in it using a power supply helped and the wireless hand set worked again!

Often this discharge isn't actually caused by the device in question, but by the BMS chip (battery management system) itself. Lithium cells by themselves are very stable over time, but gadget battery packs (even when removed from gadgets) will often very quickly discharge. Since the BMS is microprocessor it does need some power as well to run. They are supposed to not do that too quickly... but the implementation isn't always the best. When the battery gets discharged too much the BMS will cut off the power to everything (or sometimes blow a fuse) including itself. And the battery is officially dead. This trick works because BMS chips have a "kickstart function". You power them on by applying power to then. Since the input from the battery is disconnected, you need to go through the power output pins. If you apply a voltage and hold it a bit, the BMS will start up again, reconnect the cells, and the battery will start charging. Why the original charger doesn't do that... often chargers won't output anything until they get proper communication from the battery. So if the BMS is off it can't signal to the charger to start charging. Or alternatively - the charger boots the BMS again, sees that BMS is reporting an error (voltage too low) and cuts power before it has a chance to actually start charging.

I've seen plenty of folks do this sort of thing before but it didn't occur to me until recently the process is as much to do with tricking the charger to accept the battery is viable as it is to re-energising the cell(s). Sweeping generalisation alert but most chargers won't kick in unless there's some sign of life in the battery. If you've got a 'dead' car battery that a charger won't recognise, you can connect it to a good battery, connect the charger which will be fooled by the shared power level and assuming the charger kicks in, you then remove the good battery and let the charger/poor battery do their thing. Obligatory just because you can doesn't mean you should . . .

FYI, Philips has a new turntable with built-in CD player coming out in early 2026, the Fidelio FT1. No idea on price or if it will be available outside Europe. Looks pretty decent, unlike most past attempts at combining a record player with a CD player.

I'm not sure if it would help but my Lidl "Tronic" NiMH charger also has two contacts for universal Lithium Ion charging. I have been having a different problem which is cells swelling up if you don't use them. I must have had to dispose of about five even though they would charge and run equipment for about half the expected time. So far I haven't had anything as bad as R Spicy Pillows which is a forum about swelling batteries. I do wonder what will happen with "Barn Find" EV and Hybrid cars in about thirty years time. Will they announce their presence with a large bang ? Aging wheels has some candidates for that from a Chrysler Pacifica PHEV.

You said "pretty much everyone here has done this" but you should post it to the main channel anyway; there's always gonna be someone out there learning something brand new for the first time! Randall Munroe said it best in this xkcd comic: https://xkcd.com/1053/

I was not expecting that.

Batteries today just seem to be shoddy and die fast. Batteries can last, I have a Nokia phone from 2003 which I stopped using in 2013. A decade later the battery took and held a charge. Also, nice tip. Many people might have done this but I for one haven't so thanks.

I've done exactly this on a load of lithium batteries including large scale effort with an EV battery. I'd recommend the input voltage doesn't exceed the voltage of the pack, usually 4.2 volts for small batteries like this or multiples of 4.2 volts for larger batteries depending on how the internal cells are connected. From the beginning, when jump starting a dead lithium ion battery, it's a good idea to use a bench power supply and set it to constant current of between 0.5 amp and 1 amp and set the maximum voltage to 4.2 volts. But generally that's only necessary if you are using the power supply to charge it fully. Lithium ointment batteries generally cut off between 3 and 2.5 volts so you can encourage it to restart with any voltage between 3v and 4.2v for a short amount of time.

Lithium batteries are supposed to have a protection chip in them which prevents overcharging and also shuts them off at about 2.5V to avoid this problem. The fact that this one doesn't cast shame on the manufacturer. Ref: Bigclive.

Interesting tip about batteries. On a similar note, my ex-electronic repairman father-in-law told tip using a slightly higher voltage to get old electronics working again. My old Sony MXR-37 minidisc recorder wouldn’t turn on after years of disuse with either batteries or its dedicated power supply. Connecting it to variable power supply and giving in an extra half a volt brought it back to life.

My cat door runs the D cells it uses so flat that sometimes my charger errors instead of charging. Connecting them in parallel to a working battery for a few seconds is usually enough to revive them enough that the charger will take over

Thanks for the tip, Mat. Definitely worth making a video. ✅

That's a really good tip Mat. Had the camera lost the date and time when you got it working again? Also, does that camera have an 'airplane' mode? I have that on by default on my cameras that have that setting, and that seems to stop the batteries discharging.

I had no idea the Bluetooth functionality could run a battery down to zero. Seems a bit crazy that the manufacturers haven’t done something about it. Thanks for the tip! I like those Ricoh GR cameras (I have a GR I, which a friend dropped in puddle and still works ok. It’s high time I upgraded!).

That's such a useful tip I would never have even thought to do. I've had a few items with batteries that have just died like this, one was a lithium battery for a vacuume, I even cracked the battery case open and to be honest was amazed with what was inside, it was a circuit board occupied by allsorts of chips and processors etc, I was literally just expecting the usual bunch of round lithium cells linked together with a few metal stripes, not all that.

For whatever reason, as I was watching the video I thought, 'oh it's kind of like giving the battery a kick; like a jumpstart' which then lead me to having an earworm of the chorus of 'Kickstart My Heart' by Motley Crüe. This required me to listen to the song, as it had been years since I last heard it. My minds works in mysterious ways as I now want to re-edit the video to the song - that's completely ridiculous - what is wrong with me? No Answer Required. Damnit Phil! 💀 Anyway, this video lead me down a music wormhole. Thanks for that as I'm now cracking out my SoundBurger. 😁👍🏼🤍

That useful advice is about 4 days too late for the dead battery in the old Sony pocket camera I rediscovered the other day ... I ordered a replacement. However, it's a cheapie NP-BN1 battery from eBay and the old one seems a bit swollen, so maybe it's a dud best left as is. I did recover an old Parrot drone battery a couple of times using a similar trick, although my process took ages. I used the drone's charger, which initially failed to continue a charge after a few seconds. However, by flicking the charger back on every few seconds for several minutes, that short initial burst of power eventually accumulated a sufficient charge in the battery to reach the minimum accepted by the charger's test circuitry allowing it to contunue, as yours did :)

Dodgy? If it's good enough for you, it's good enough for me.

I need several hundred of those "Dodgy?" stickers. In fact, it may be far faster to simply have 2-3 non-dodgy stickers printed and just assume the rest is.

I recently got anm Lamy Safari ncode pen recently. It was dead and it was hypthesized the same issue is at play. Unfortunately, that thing didn't have a removable battery but now I wonder if I could have disassemble the usb cable and achieve something similar. We'll never know. I sent it back. They didn't have another on discount. And not even on black Friday did anyone have a good enough deal for me to try again. Still very bitter about it.

Works for most rechargeable batteries. For example AA ones; push the two positive ends together and bridge the negative with some wire, just for a few seconds. It gives the dud battery just enough power to be recognised by the charger. Be especially careful with Lithium Ion (corrected from NiMH) cells, they're more dangerous and could go into thermal runaway if shorted too long. The dud will never be as good as it was, but it will be better than a dud one.

You're right - you were lucky to get that bad boy in stock. I have tried this a few times and it works sporadically. Can't tell why it works sometimes and sometimes it doesn't. Something I find easy if you don't have a DC power supply is to get 2 razor blades and shove them in the slots in power tool batteries then get little alligator clips to connect to other razor blades in other power tool batteries. When I need 5v, I have a 4 AA thingy with bare wires.

This is excellent - I had a similar problem with a battery in my Sony camera but didn’t think to try this. I’ve still got it somewhere so may give it a go

Seen this done before for an Akai wind controller (MIDI controller, nothing to do with trouser coughs). They used AA cells to do it, which is probably a little safer.