It's not a good idea to leave the battery turned on, as fully discharging the battery will decrease its life expectancy. For optimum battery life it should not be discharged by more than 80% of the battery's stated capacity
(12Ah for your 15Ah pack).
I don't have an external controller to test, but I have just checked the current consumption of an MP4 vector controller with the throttle LEDs connected and it was drawing 54mA at 55V, which is approximately 3 watts of power on standby. The controller I tested was not fitted to a wheel at the time, so the current consumption will be slightly higher when the three hall sensors
(and Pedelec sensor if fitted) are also connected and drawing additional power.
If we round it up to 75mA
(0.075Amp) it doesn't sound very much, but it will still consume 1Ah of power every 13 hours and 20 minutes. A fully charged 15Ah battery in perfect condition should theoretically last for around 200 hours
(8 days and 8 hours), so your
"little more than a week" seems to be about right.
If you had returned from a run which had used half of the battery's capacity and left the battery switched on, it would be completely flat after only 4 days and 4 hours. If you did the same thing with a LiPo pack without a
BMS to protect the battery, your battery cells would suffer permanent damage and could become dangerous to use if they were discharged too far.
If you want your battery to last longer, make sure you switch it off when not in use and try not to fully discharge it. Also make sure that you charge it at least every other month during the winter if it is not being used.
Alan
