Low Battery Cutout for Bosch Gen4?

Hey Stephen,

Bingo! You said it better than me!

"I do interpret that 0% would mean all your available battery capacity has been used and that anything remaining is that which is required to ensure that the battery is not damaged by excessive discharge."



I think that's a great idea for a thread! If someone gets approval and sets it up, we'll keep an eye on what is posted.
 
I do understand the cutting of the assist when battery is below 10 percent, but when this does occur, I would still like to see the level drop linearity or reflect actual level. As it is now when this level is reached the battery level will drop from the 10% to 1% and remain there.
If I do have to "limp" home I'd like to see what I have left for lights and e-shifting.
R&M Charger 3.
 
My apologies!

First, eShift reserve power cannot be adjusted, it is what it is. I'm not sure the exact amount of energy set aside, just that it's good for (50-100) shifts.


Moving on to lights...

I'm not entirely clear on your question: "Simple answer... can I leave the lights alone at full power always on, just as the factory setting?" I'll throw some more info your way, and if this doesn't not answer it, we'll keep at it! :)

Unrelated to reserve power: The lights will of course consume energy during normal use. The amount of energy consumed depends on the current draw/ specs from the lights. During normal use, this consumption is not adjustable. You can replace your light with a different light that uses less energy, but that is it. The more energy your lights consume during usage, the faster your battery drains. This has no bearing on the reserve power, but does affect how quickly you get to the reserve power.

For reserve power (after the Drive Unit cuts-off due to low battery): The DU will save enough energy for 2 hours of light operation at the wattage you select (3W to 18W, selected by Dealer.)

I feel like this is still somewhat complicated, so I'll try to give some examples.


For the sake of the example, we'll pretend that your front/rear light combined require 10 watts for normal operation. If you keep them on all the time, they will use 10 Wh every hour. If you ran your lights for 4 hours while riding, you would have theoretically consumed 40 Wh of your battery.

10w * 4hrs = 40 Watt Hours


Regardless of what your reserve power is set at, the above would theoretically be true.

If you did you entire ride without your lights turned on, they would consume:

0w * infinite hrs = 0 Watt hours



Once your battery gets low enough for DU cut-off, we start looking at the "2 hour reserve light power mode." During this mode, your lights will not necessarily have the 10 watts they "want," but will instead have the amount selected between 3w and 18w. If you wanted your lights to have the same brightness during reserve as they do during normal operation, you'd have your dealer set the value to "10w" in the Bosch Software.

The amount of light power reserve would be:

10w * 2hrs = 20 Watt Hours


If you wanted to maximize range, and didn't care about brightness during the reserve period, you might have the dealer select 3 watts.

The amount of light power reserve would be:

3w * 2 hrs = 6 Watt Hours



For the sake of further explanation, if you had your dealer set the reserve power to 18 watts, your lights would still only operate at 10 watts, but we'd "waste" all this extra saved energy.

18w * 2 hrs = 36 Watt Hours



Looking at the total demands on your battery capacity, we can think of it this way:

- Energy consumed by normal riding: DU assistance, lights, eShift, and smaller functions (DU processor, sensors, display charging, etc.)
- Energy saved for 2 hour light power reserve (0 - 36 Wh)
- Energy saved for (50-100) eShifts (unknown)


Does this help, or did I make it worse?
Hi
i'm user of a Bosch G4 625wh bike,
recently my dealer activate the light plug to connect a 7,5watts light

Lezyne E-Bike Macro Drive 1000​

and the config was 18 watts output... this do a reserve of 11% of battery, to big for me.
recently i went to my dealer bosch and change 18 watts for 3 watts output, and reserve change to 3% of battery.

i Think watts only do it´s calculate the reserve, because light its 7,5 watts and it´s working fine with 3w and 18 w config.

could you confirm this?... thanks.
 

Attachments

  • luz.JPG
    luz.JPG
    82.3 KB · Views: 202
Last edited:
Back