Big Clive's NiMH charger
So, there’s this Scottish Youtuber, Big Clive, who has a channel about electronics and electrical appliances, and I’ve been binge watching him for the last few months. To be honest, he was one of my main inspirations in getting a soldering iron.
In one of his videos, he built a trickle charger for NiMH and NiCd batteries, and was so kind to provide the files needed to have the PCB files ordered to do the charger by yourself. The project seemed easy enough and giving a lot of satisfaction so I could not stop myself from doing it on my own.
Here is the video I’m talking about, the link to the PCB designs is in the description.
I ordered the PCBs from JLCPCB, and it was only a few dollars, and the shipping took around 2-3 weeks.
After ordering the PCBs, I started looking for the other components.
The hardest part was finding the right micro USB connectors. To match the board, the connectors had to have four pins in two pairs, and preferably all pointing downwards to the board. I could not find the right ones in any of the Polish electronics shops nor e-commerce platforms. Eventually I found the right parts somewhere around the 8th page of Aliexpress search results, so I ordered 20 of them to be safe for the future.
The rest of the elements was much simpler to find, yet I still had to source them from three different places. That was so surprising, as everything here seems to a standard electrical component. Looks like GPUs are not the only things suffering from shortage. Anyway, here are all of the required components.
Lol, only after taking the photos, soldering everything together etc I realised I did not include the LEDs in the pic.
- PCB from Big Clive's design
- micro USB connectors
- AA battery holders
- 120 Ohm resistors
- 470 Ohm resistors
- 1N4007 diodes
- colour LEDs (not shown)
I first soldered the USB connector. Fit like an USB glove.
Then came the 1N4007 diodes.
120 hm resistors came next. I helped myself with some electrical tape to keep everything in place as I was soldering from the other side of the board.
I don’t what why I kept forgetting about the LEDs, I did not take a picture as they were soldered, so here is a photo with the LEDs and half of the battery holders. I taped the holders from both ends because they refused to lie flat on the board.
And don’t forget about that 470 Ohm resistor at the end of the board!
And the ready charger. For testing I put some IKEA LADDA 2450mAh rechargeable batteries which I had discharged to around 1.12 Volt.
Look how pretty it is, I really like how it turned out with those warm amber LEDs, it could as well be a nice night lamp, or I might hang it on a wall to just be there and present itself. I also added some legs so that it does not lie on the soldered ends. In the future I might make another one and combine them into a tasty charger sandwich.
And does it charge? I measured the charge current, I got 50mA throught the battery connectors. As I mentioned above, I put four discharged AA batteries to see what happens. After 48 hours I put them to my “normal charger” which reported that they were halfway charged. After four days, they were “almost charged”. Clive said it should take around a week to charge high capacity batteries, and that seems to be true in my case.
Thanks for reading, that was a fun little project, took some planning and searching and waiting, but eventually turned out very well.
If you liked it, please checkout Big Clive’s Patreon page, and if you would like to help fund my future projects, please consider to