Adjusting the low voltage cut off on an ebike controller.
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- เผยแพร่เมื่อ 20 พ.ค. 2024
- I fitted a 48V controller to my ebike which was fitted with a 36V battery. Unfortunately the 48V controller low voltage cut off was preset to about 36.5V which is the nominal voltage of a 36V battery causing it to cut off after only about 4 miles and not the 20-30 miles I am expecting to get from this ebike + battery.
To solve this I reverse engineered the circuit diagram for the battery feedback resistor network. Then made a spreadsheet to check the expected voltage divider ratio to that measured with a multimeter. After I checked my circuit diagram was correct I then calculated feedback resistors for a 26V cutoff voltage and replaced them on the PCB. This is a short video about how I went about doing it all. - วิทยาศาสตร์และเทคโนโลยี
That was interesting, thanks.
Nice mod. 👍
: o )
What is the controller behaviour after U.V. kicks in...
Does it restart after recovery or does it require a power switch off before restarting ?
Have you measured the upper & lower gate drive voltage when battery voltage is around 26.5V ?
If gate drive volts is insufficient, the mosfets could overheat & fail ( operating in near ohmic region)
What's the runtime now , after modification.?
Thanks for the interest.
After Under Voltage is triggered it requires a power cycle before restarting.
There is in intermediate 15V switch mode voltage converter which powers the gate drivers and other circuitry. This converter works down to 22V so I can only guess it's fine at 26V.
I can now use the full range of the 36V 13Ah battery so the range is good but as always related to hills and overall speed. I did about 15 miles at about 20mph in the test for this video and there was still plenty of charge left when I got home again. I would easily expect 20 - 30 miles at the regulation speed of 16mph on a full charge.
@@o0OMouseO0o Thank You 👍
Do you still have the tdi bike?
Hi @kevindonley1496, Yes, however the gearbox broke with the same shattered wended diff fault twice. So it is off road for a while whilst I workout how to make it stronger without heat damaging the temper of the gears by welding them.