KT Controller Low Voltage Cutoff

[Kyogiro]

I was wondering if there is a way to adjust the low voltage cutoff. I think the KT is doing it the "smart way" (detects when cells are below a certain level regardless of a 48 or 52 V battery pack). I have a spare 52V battery which I took for a long ride yesterday (I initially planned for a 200 km ride but cut short for a 137 km one instead because I lost my halt point to recharge my battery). Did a lot more off road than I initially planned (I planned to no go off road).

I think the standard cutoff should be around 3.07 V (40V) for the stock 48V battery. Never tested it that out though since I essentially use my Rhino - with the stock battery - for commuting and I never commute that much and most of the time in low PAS.

The ride is available on Strava : Ebike Rad Rhino (Rover) Test | Strava

 

[AHicks]

I prefer a built in "safety factor" when deciding my cut off (LVC). I don't want to loose power due to the pack shutting down unexpectedly. An example of something I'd prefer to avoid might be grabbing a handful of throttle while crossing a busy intersection. The bike leaps forward 5', then the LVC shuts down the battery due to voltage sag - leaving you in a rather embarrassing situation.... Another might be a steep hill in the last half mile of your ride.

These scenarios in mind, my LVC is set at 44, but I generally charge when the voltage drops to 46.

Point being, I don't need the extra range provided with a lower LVC, so I don't push it.

 

[Kyogiro]

Thanks AHicks, I get what you're saying. Where do you see the LVC in the KT controller settings ? I though it might be P5 but not sure.

I don't mind the fact that there is a high or low cutoff, I just need to know where it is and at what level it is set off. Like today, I commuted for about 40 km (24 miles), I finished with the screen indicating 46 V which is fine but if I had to go longer, I wouldn't know when the cutoff would happen, I just knew (felt) I was on the lower tiers remaining.

Of course, the battery indicator is absolutely no good (not even half way used according to it...).

Next sunday, I'll try again to do a 200 km ride (with a halt at half point), if I could know at what level the LVC is, I can carefully ride to be sure I'll come back home easily. I really don't want to be 50 km (31 miles) from home and pedal all the way especially when I am fully packed (I easily double the weight of the bike when I'm distance riding with the extra big battery pack and my gear).

 

[harryS]

In the LCD3 settings, it's C12. C2=4 sets LVC for 30 and 40 volts (for 36 and 48V packs). Each step dowm lowers LVC by .50 volt. Each step up raises it by .5 volts. C12 varies from 0 to 7, so the LVC range is thus 28 to 31.5 and 38 to 41.5V. I've tried lowering it on my LCD3, and it does work. My LCD1 has no C settings beyond P5, and I never tried the color LCD's.

I don't see my KT controllers recognizing the difference between a 52V and a 48V battery though or even having a 52V LVC. So when you use a 52V battery, LVC is a bit low, if you use the default of 40V (2.86V/cell),

 

[Kyogiro]

Thanks mate, very useful.

 

[razz]

In the LCD3 settings, it's C12. C2=4 sets LVC for 30 and 40 volts (for 36 and 48V packs). Each step dowm lowers LVC by .50 volt. Each step up raises it by .5 volts. C12 varies from 0 to 7, so the LVC range is thus 28 to 31.5 and 38 to 41.5V. I've tried lowering it on my LCD3, and it does work. My LCD1 has no C settings beyond P5, and I never tried the color LCD's.

I don't see my KT controllers recognizing the difference between a 52V and a 48V battery though or even having a 52V LVC. So when you use a 52V battery, LVC is a bit low, if you use the default of 40V (2.86V/cell),

There a way to compensate for that? I'm looking at a second battery for my radmin4 (stock 48v battery). Wondering if I should get a 52 volt with the KT-LCD8? Or if that would be wasteful due to the incorrect cut off.

 

[BKing]

The 48v has 19% unusable charge left using a 42v cutoff.
The 52v needs 44v cutoff to prevent stress but it can be set a few volts lower. Just don’t get in the habit of running it down. 44v is 12% unusable charge left.