My father bought this garbage 10 years ago. The battery (NiMH, 3S, 600 mAh) never lasted more than 5 minutes but now it doesn't even last 1 minute.I plan to fix it, but I may need some help in order to ensure that his house doesn't burn down.Please chime in if you have any advice or opinion, don't hesitate to call me a retard if you think it's warranted.https://www.argos.co.uk/product/4438757
>>2982511You'd probably be better off just upgrading the NiMH battery to higher capacity. Swapping to lithium, modifying the charging circuit, etc. Probably be cheaper just to buy new clippers.
>>2982511maybe your father needs to learn the age old wisdom "buy nice or buy twice"
>>2982511anything with rechargeable batteries is bullshit.stuff like this is hard to replace, anything you put normal batteries in (despite the year of out lord 2026) doesn't work half as long with rechargeable in.if you know the battery then order a new one. do you need one of those tab welder things to put it in?if you need to ask then i wouldn't fuck with battery mod but i know even less about it than you.for what its worth i would buy a wahl super taper with a plug on the end and never worry about batteries again. 50 quid at sally beauty other stores are available.looks like theres just a resistor to charge it. lipo you probably need some charge controller pcb in there, then its easy you have mains plug in and switch/motor out.is the cardboard thing the switch? whats the switch at the bottom do?
>>2982512I split the battery and did three deep discharge cycles on each cell, they went from 60-70 mAh to 300-450 mAh. Still mediocre, but the internal resistance is below 45 mOhm so they won't be binned.I can build a new battery from IKEA LADDA cells, 2450 mAh, which should last enough for his needs.However, I have big doubts regarding the charger. It is nominally 4.5V 1A, however without load it outputs 5.27V, and with a 5 Ohm load it gives 4.61V 0.85A.The PCB is primitive and I doubt it charges the batteries correctly, see pic.
>>2982518Trust me, I tried. He's convinced that paying less means saving money and nothing can convince him otherwise.I bought a Philips OneBlade 9 years ago and it still works like new, he paid more for half a drawer of trash that stopped working after two uses.His logic must be that he paid less for each of those individually than I paid for one shaver, so that means he's saved a bit of money on each purchase...
>>2982536>tab welderAlready have one.>i would buy a wahl super taperThat's what I did, running like a champ since 2018. Dad would never pay £45 for it, he'd rather spend £25 every 2-3 years on cheap trash.>lipo you probably need some charge controllerMy plan was to use the current charging circuitry, because the stupid charger said 4.5V on the box. So 4.5V - 0.2V (diode) means that I could add a 0.33 Ohm resistor to drop that to 4.1V.The current would be fine, 0.85 A is just under half the capacity of the lithium battery I have (1800 mAh).But with the 5.2V that the charger actually outputs, I don't know...
>>2982536>is the cardboard thing the switch?No, it's just a PCB-like material. Only the two populated metal rings are interconnected, all others are dummies. It sits next to the motor.>whats the switch at the bottom do?It is activated by a long plastic tab, that's the on/off switch, the only one on this device.
>>2982536>looks like theres just a resistor to charge itIndeed, when the switch is off (up in my schematic), the current goes through left diode, right diode, big resistor.When the switch is on (down), the current flows through left diode to battery + motor, so it relies on the motor to sink enough current (voltage?) to make the remaining voltage safe for the battery.I will take measurements and update the schematic.
>>2982511since you are asking how to do this, you do not have the skills required. buy a new one.
>>2982511Get a charging module like the TP4056 or just tap the motor directly to the barrel jack and forgo the wireless.
for more assistance, add me on discord.My user is : anon58394
Update: with the motor running, the voltage at the battery contacts drops below 3V, completely unusable. Reminds me of pic.>>2982633My goal is to improve it a bit, otherwise I could just leave it alone. It works wired already.>>2982686>discordI don't use it, but even if I did, it wouldn't be fun. Thanks for helping nonetheless.
>>2982633>TP4056Ordered, will be here in a week.
There's this vape that I found, it has a charging circuit and the battery seems decent.Maybe I can try it before those TP4056 boards arrive.
Looks fairly generic. The suck sensor will have to go.For so e reason, it drops the voltage from 3.7V (red cable from battery) to 3.4V (blue cable to heating element).No bueno.
Just buy a replacement battery. The 600mAh wasn't the issue, the battery was likely left depleted for long periods of time.
The battery is rated for 850 mAh but squirted 920 mAh overnight. Definitely a good one.I need to detach the display, because the distance between the charging board and the plastic shell of the trimmer is too wide, so it'll be useless.>>2982812>Just buy a replacement battery>/diy/???
>>2982872>it'll be uselessActually, scratch that. I need a way to show the charging status and a low battery indicator, but I don't know how to connect the existing LED to this board, so I'll have to find a way to keep the screen and somehow shove it through the shell.It also shows the battery level in real time, which would remove the need for guessing.The PCB pads are responsible for two groups of LEDs, and I only need the bottom group, so I'll try to solder some ribbon cable between the board and the display.
Looks like there's a thick lump of black plastic that I have to cut through.There are no suitable ribbon cables in my stash, I will have to sacrifice some otther cable.
The old PCB is now stripped, all unnecessary wired are gone.
Found a good spot for the display. I wrapped a zinc strip to the soldering iron to cut the hole... looks like shit to be honest.The display is curved but the shell is flat, so it feels off. I'll fill it with hot glue.
RIP some random USB cable.
And OF COURSE it won't fit because I'm a retard and forgot about the screw hole, and I can't drill through this fucking board.
>>2983098Use a TP4056 module externally, and make sure you change the current limiting resistor to a safe level for your new battery. Wire its output to a barrel connector that fits the barrel jack on the original PCB, and replace the flyback diode.
How do you know where to connect the battery display bro
>>2983098The e-cig circuit board uses PWM to regulate its output so it probably won't work well to drive the motor.
>>2983108Crap... Makes sense for it to be optimized for one specific load.>>2983107It's easy because I only cared about the pads from on side, so just keeping the same order was enough.The display was desoldered from that same board.
>>2983105>TP4056 module externallyAs in "outside the trimmer's body"? I want it to be more convenient than it was with the original charger, an extra bespoke adapter doesn't sound convenient.Ideally it would charge from any random USB plug.The TP4056 modules haven't left the airport yet.
It's fits sideways. Not as pretty, but just as functional.I cut a piece from a glue stick and shoved it in the round hole.Tried to cut a small strip from the PCB but it splintered and a large piece flew across the room.
>>2983108You were right, it did work like shit.I have connected the motor straight to the battery, through the old switch. Runs like a champ but the display never lights up while running because the board can't sense that something is using the battery.As it is, the display is only useful while charging.
I tried shorting the load+ pad to battery- with a resistor and the display lit up.The highest resistance it reacts to is ~100 kOhm. I have no idea how to link this with the existing switch, so instead I replaced the old red LED with a momentary switch. The hole needed a bit of filing because the switch is 0.5 mm thicker, but otherwise it fits.
This is pretty much it.I will test it later, hopefully it runs for >20 minutes or else I'll replace the battery with a bigger one.
Tested, ran for an hour and a few minutes. During the last 5 minutes it is weaker, unfortunately there is nothing to cut off the power when it is discharged.The TP4056 haven't arrived yet, I'll use them for other projects.Thank you for reading my blog, please like and subscribe!
