Powered wheelchair for the beach

@dubbadan That looks like quite the project. When you have the time you can show and tell us how it is made, including the mechanical and electronic systems. Many of us here are of an age that may be our next mode of transportation.

I would love to do that. I'll take some photos when I can, might not be for a week or so. Until then, I can list the main electrical and electronic components:

2 x 24V 250w DC motors with gearbox (salvaged from an old power wheelchair)

2 x ridiculously heavy lead-acid 12v batteries (salvaged from the same chair)

2 x IBT-2 h-bridge motor controllers (with extra heatsinks, in a jiffy box with a small fan)

Raspberry Pi Pico

Some extra power circuitry

Simple analog joystick

I also have a LiIon (ex- EV) battery made up to 36V that I'm considering using instead of the lead-acid monsters, but this would involve extra power-stuffery, time, money, etc.

The code I am using currently is mostly just simple if statements, which works ok, but is a bit clunky in terms of the joystick-to-motor response. I am working on something that will hopefully work a bit more smoothly. I originally wrote the code in C++ for Arduino, but have been learning MicroPython for the Pi Pico. It's been a long but (mostly) enjoyable learning journey.

@dubbadan Keep in mind that the safe LiFePO4 battery is a drop in replacement for lead acid but 1/2 the weight (about 30 lbs) but expensive. You can make your own as well for a good cost savings, just don't cheap out on the BMS.

Thanks @zander. A while back I made up the battery pack to 36V nominal with LiIon 7.2V modules from a Nissan Leaf, with a hefty BMS installed. It's a beauty. I'm hesitant to use it because of the extra power conversion I'll need to make, which then means considering power losses and heat management. Also, I've been saving it for a different project, but it may be necessary to use it here due the problems caused by the weight of the lead-acid batteries.

@dubbadan I don't have experience with that size of voltage drop, but at least in theory you should be able to get or make a DC to DC converter often called a Buck converter. You may find them in the Solar field, they generally work in units of 12V and there are lots of reasons to go from 36V to 24V. I will have a look at my source to see if they exist.

@dubbadan Try this one https://daygreen.com/en-en/collections/36v-48v-to-24v or

https://dakotalithium.com/product/24v-36v-48v-dc-to-12v-dc-10a-dc-dc-converter/