I have this remote:
https:///collections/remote-controller/products/torqueboards-2-4ghz-mini-remote-controller
It runs on two AA-batteries in series (1.5V *2 = 3V). I want to make this rechargeable via a usb-port so I wanna stuff a lipo battery inside it
I have a 1S 500mah lipo with a built in bms that I wanna use for this. The maximum voltage is as you all know 4.2V so i guess Iāll have to step it down to 3 or 3.3V in order to use it with the remote. I then have to add a USB-port and step down the 5V from that to 4.2V to charge the battery. I also need to limit the current here to 500mah to charge the battery at 1C.
Can anyone help me with where I can find the step-down converters? I know some electronics but Iām far from an expert! If you know of any parts that can help me with this or if you have a better idea or solution, please let me know!
Iāve done this, and while itās cool and all, I donāt really know if I recommend it. The AA batteries last so long and in 1.5 years of daily use, Iāve only had to charge the lithium-ion battery twice, and the second time was yesterday. I guess that means the microUSB jack wonāt wear-out, huh?
I have about 8 Mini Remotes and I only modded this one. I really fail to justify the effort to mod any more. The AA batteries last so long, especially if you get the really good ones. Now I use āEnergizer Ultimate Lithiumā AA batteries (not rechargeable)
I modded all 3 of my mini remotes with lithium ion cells,1s bms for charge only, voltage display, and a decent rocker switch for power. Never bothered with the step down voltage and have not had a single issue. Like @b264 said, the cell must be smaller than 18650.
The thing is, with primary cells itās guaranteed to run out at some point on the road. So you have to carry spare batteries and a phillips #1 screwdriver. Or be ready to walk. Which sucks balls. So any kind of rechargeable is preferable so you can reasonably control the state of charge.
I had to change batteries on the road 2 days ago.
But, the remote likes 1.5v not 1.2v like common nimh AA (eneloop)
True that, but using Mini Remotes daily for years Iāve only had to āchange batteries or kickpushā once and I did actually have a tiny screwdriver and two batteries in my bag.
But you do have a point.
If you modded it to have a battery gauge instead of be fully rechargeable I think itād be fine also.
I will either do some kind of mod on the mini receiver or build a firefly remote instead
At the moment I always carry spare batteries and a screwdriver. I also always carry spare belts and all the tools needed to change them so iād say Iām quite prepared
The voltmeter is one of these. There are a lot of different ones. This one is 0-100v, but shows single digit volts as ā3.41ā not " 3.4". Has the adjustment pot. Itās the 3 wire version ā just connect the blue and red together. Minimum voltage is about 2.5v or so. Unfortunately this makes things not great with eneloop, but as you said, getting a voltage indication is 99% of the battle. I can use duracells here (those fucking things leak in every device I put them in).
To make the cavity I traced the meter with magic marker, used a brad point bit to drill 2 holes, then diagonal cutters and utility knife to creep up on the fit. hotglued everything in.
Tactile switch, I think a 6x6x7 will be perfect. Will report when I test one. The hole for the switch was made with a 5/32 brad point bit.
I made a AVIO remote, but unfortunately I canāt get a good grip with gloves that lets me have full range of the trigger. Maybe just need practice.
I know some electronics but Iām far from an expert! If you know of any parts that can help me with this or if you have a better idea or solution, please let me know!
I modded all 3 of my mini remotes with lithium ion cells,1s bms for charge only, voltage display, and a decent rocker switch for power. Never bothered with the step down voltage and have not had a single issue. Like 
