This might seem out of line for some of you, but I'm researching this idea.
I've worked alot on motor controllers, hoping to be able to sell them. After much failure and the general complexity assembling them, that project is still under development. Early on I made my own, quite rough, battery management system - from day one it has worked as programmed.
Lately I picked up the bms project and developed my own balancing circuit and a cutoff-switch, much alike methods LVC protection. I'm planning to offer these different parts.
1. 8 cell monitoring system - works with 'any' type of chemistry.
- 9 input wires from battery.
- 4 output wires to balancing system.
- 2 output wires to LVC system.
- 2 output wires to display unit.
- some power wires to the different units.
This basically reads the voltages and makes descisions to controll the balance board. Built in functionality makes sure no load changes happen during sampling. It sends data to display unit for viewing. 1uA shutdown current draw. Pack self discharge is probably higher.
2. 8 cell balancing system. Using a very complex system of fets and microcontrollers, I've realized a effective pack to cell balancing. Made for connecting to the monitoring system as a 'shield'. Balances the cells, nuff said.
3. 128x32 FSTN LCD display unit. Reads values from monitoring system and shows them to the user. Also shows current consumption. Can be programmed from a computer via USB.
- 2 input wires.
4. Leds display unit. Uses some leds to show the state of the pack. Basically a stripped nr 3 to lower cost. Features computer connectivity like nr 3.
5. LVC cutoff. Disconnects the pack from any load and shuts down the bms. Note that the bms monitors current (losslessly ofc) so that it will not cut off power due to cell-sag. HVC cutoff does exist, but isn't as effective. The switches I use are MOSFETS, and they work as diodes when shut off and the pack is charging.
Startup cost will be higher than what I can make them to be later on. I picture taking 25 dollars for 1, 2. Number 3 is somewhat more expencive, around 40-50 dollars. Number 4 is around pictured to be around 20 dollars. I don't have a price for number 5, but probably around 20 dollars to - but more expencive for MOSFETS made for higher voltages.
To realize a 100V (24s) lipo BMS system would cost around 220-250 dollars while a 33V (8s) full system would cost around 120 dollars. Parts run about a third of total cost, so I'd make more money working more where I allready work. But I foresee this product could be sold for quite some time.
Would you be willing to pay the prices mentioned? Oh, and no open source project here - I've already tried setting microcontroller - heavy open source projects to life before. Just end up teaching people about electronics 101 + C++ 101 -.-.
I've worked alot on motor controllers, hoping to be able to sell them. After much failure and the general complexity assembling them, that project is still under development. Early on I made my own, quite rough, battery management system - from day one it has worked as programmed.
Lately I picked up the bms project and developed my own balancing circuit and a cutoff-switch, much alike methods LVC protection. I'm planning to offer these different parts.
1. 8 cell monitoring system - works with 'any' type of chemistry.
- 9 input wires from battery.
- 4 output wires to balancing system.
- 2 output wires to LVC system.
- 2 output wires to display unit.
- some power wires to the different units.
This basically reads the voltages and makes descisions to controll the balance board. Built in functionality makes sure no load changes happen during sampling. It sends data to display unit for viewing. 1uA shutdown current draw. Pack self discharge is probably higher.
2. 8 cell balancing system. Using a very complex system of fets and microcontrollers, I've realized a effective pack to cell balancing. Made for connecting to the monitoring system as a 'shield'. Balances the cells, nuff said.
3. 128x32 FSTN LCD display unit. Reads values from monitoring system and shows them to the user. Also shows current consumption. Can be programmed from a computer via USB.
- 2 input wires.
4. Leds display unit. Uses some leds to show the state of the pack. Basically a stripped nr 3 to lower cost. Features computer connectivity like nr 3.
5. LVC cutoff. Disconnects the pack from any load and shuts down the bms. Note that the bms monitors current (losslessly ofc) so that it will not cut off power due to cell-sag. HVC cutoff does exist, but isn't as effective. The switches I use are MOSFETS, and they work as diodes when shut off and the pack is charging.
Startup cost will be higher than what I can make them to be later on. I picture taking 25 dollars for 1, 2. Number 3 is somewhat more expencive, around 40-50 dollars. Number 4 is around pictured to be around 20 dollars. I don't have a price for number 5, but probably around 20 dollars to - but more expencive for MOSFETS made for higher voltages.
To realize a 100V (24s) lipo BMS system would cost around 220-250 dollars while a 33V (8s) full system would cost around 120 dollars. Parts run about a third of total cost, so I'd make more money working more where I allready work. But I foresee this product could be sold for quite some time.
Would you be willing to pay the prices mentioned? Oh, and no open source project here - I've already tried setting microcontroller - heavy open source projects to life before. Just end up teaching people about electronics 101 + C++ 101 -.-.
