Question about watt hours display on DPC18 for BBSHD

kiltedcelt

100 W
Joined
Aug 19, 2015
Messages
158
Location
Chicago, IL USA
Okay, so I have a "48v" BBSHD that I purchased a few years ago from EM3EV with a 52v triangle pack. The pack is 17Ah and it was charged to 90% before I took it out for the first test ride, which is when I snapped the photos I've attached. On the display I guess I have it configured to show the MPH on that dial graph going one direction (clockwise), and the bars in the smaller display going counterclockwise are showing what, Watt Hours per mile, estimated based on assist level and how hard one is pedaling? I wondered about this because so many range calculators seem to assume everyone is riding at an average power usage of 20 watt hours per mile (if I'm remembering that correctly), and here it would seem that in assist level 4 (3 is actually fairly comfortable for a lot of my riding unless it's ridiculously windy), show me only using about 5 watt hours if I'm understanding what I'm seeing. If I kick the assist up to Level 6 then I'm still only using 10 watt hours to go 18 mph. Either I'm putting far more effort in to the PAS or are the calculators all assuming that everyone is just using throttle? My concern has always been to get the maximum range available and I only want *some* assist - I still want to do the work to keep the bike (in this case *trike*) moving - ie. pedaling, and pedaling enough that I'm still getting *some* exercise. This seems ideal to me if I'm reading that display correctly.

Also, after I took these photos, I rode the trike to work the next day with major headwinds going both ways and had the assist level mostly at around Level 6 I think for a lot of the ride both ways. The commute is about 11.5 miles each way without about 5 miles of it on city streets in stop/go traffic. Even with what would seem to be higher assist level, I didn't put much of a dent in the voltage of the battery for that 22+ mile ride. I'd have to go plug the battery in to check the current voltage but I believe it was only down to about 54-53v by the end of the ride home from work. I did use this battery coupled with a Cycle Analyst and a MAC geared hub motor before I got the BBSHD. With the MAC motor I was able with an economical level of assist to get over 90 miles of range from a single 100% charge. I did post about this triangle pack a few days back, mainly because I can't figure out a decent way to mount it on the trike frame and still have it protected against the elements and potential theft, while also having it removable for charging.

I just purchased a Jumbo Shark 52v 17Ah battery from EM3EV and it should not only be easy to mount with the actual Utah Trikes battery mount made for my frame, but it should have the same capacity and potential range as my current triangle pack. I'm mainly wanting to know if I'm understanding what I'm seeing on the display correctly and also what else I might be able to do in terms of settings or maybe riding habits to make sure I'm maximizing the potential range that the battery will give me. Ideally I'll commute and do some rides with a full 100% charge just to get an idea, averaged out what my potential maximum range is, but for the most part I'm only going to charge the battery to 90% in order to extend the life as much as possible. So, am I reading that display correctly, and any suggestions on how to get the maximum range possible?

Oh yeah - and pay no attention to the odometer reading on the display. That is cumulative mileage from like two years ago - like the last time I used the motor and battery. I guess I never reset the trip odometer. That's kind of a pain in the ass because there's not an easy way to do that for each ride. Is there a setting to just turn that into just a plain odometer, or just leave it as-is? Would getting a programming cable help with tweaking settings any? One thing I can think of, is that I don't really need a full 1000w, and one thing I *would* like is a more easy application of power via PAS when pedaling at slower speeds.

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AFAICT from this manual
https://cdn.shopify.com/s/files/1/0537/7176/3911/files/DPC18_Display_Manual.pdf?v=1628090638
that portion of the display you refer to as watt-hours is either presently being used amps, or presently being used watts. It appears to be set at Amps given the numbers displayed and the "A" between 20 and 30.

Power View:
This allows you to select your viewing
preference for the power of the motor. This
may either be in Watts or in Current (Amps).
Press the button to select this option and
toggle it using the or button. Press the
button again to save your setting and exit this
option. Use the button to scroll down to
the next display setting.

Unfortunately I don't see a function to show watt-hours at all.

If you still have your Cycle Analyst, you can wire it between the battery and controller and use it (mounted anywhere you like, even in a bag, unless you need to see the data realtime) to monitor all the power usage statistics.


Regarding power usage, calculators generally use an assumption of no human input to accurately calculate system power usage, as human power is not generally constant and predictable. Some calculators like the ebikes.ca simulator have a field to choose human input amount, but it is more accurate to choose zero unless you know how much input you personally are generating, using a meter designed to measure this. (like a torque sensor and cycle analyst, etc).
 
Thanks Amberwolf. I must've read that passage at least a couple times but it didn't register that the setting was amps or watts. I think watts is probably a more useful setting. I don't still have that Cycle Analyst, unfortunately. However, I had been planning on getting another one and performing the conversion my BBSHD from the DPC display and the onboard controller in the BBSHD to an external controller and CA, primarily because playing around with solar power for the motor was something I wanted to do at some point. I do remember from using the CA that you could set it up to show what wattage you were using and obviously, the higher you went on assist setting, the more watts you used. I generally found that when I kept my watts around 300 or so, that was when I got a favorable amount of assist without it being too easy, and keeping watt usage lower like that seemed to translate to much better economy when it came to battery usage.
 
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