Calling all math majors

[Jeremy McCreary]

That's really good. I believe you are on a BBS02B? You must be riding with minimal assist.

My BBS02B burns 8 watt-hour/mile (years of data) with a combo of PAS1/PAS2, I have a 15AH pack on my BBS02, rated for 720WH but it's more like 630 WH in real life,. I put on 38 miles last week in the cold. That would be 300 watt-hour..I've used up half the battery. It's at 48 volts. so that works out too, I'll put on a power meter when I recharge to see the actual AH. I know I'm putting it to the math majors.

As for estimated range, I know what my bikes and batteries can do, but it's always good to be home before I'm under 50%.

Without good empirical data like this, the math is pointless anyway. Garbage in, garbage out always applies.

 

[slitespd]

That's really good. I believe you are on a BBS02B? You must be riding with minimal assist.

My BBS02B burns 8 watt-hour/mile (years of data) with a combo of PAS1/PAS2, I have a 15AH pack on my BBS02, rated for 720WH but it's more like 630 WH in real life,. I put on 38 miles last week in the cold. That would be 300 watt-hour..I've used up half the battery. It's at 48 volts. so that works out too, I'll put on a power meter when I recharge to see the actual AH. I know I'm putting it to the math majors.

As for estimated range, I know what my bikes and batteries can do, but it's always good to be home before I'm under 50%.

Yes I am riding with a BBS02 with an 20aH battery. I am extremely happy with it. I do ride with minimal assist as you suggested,……….. mostly PAS1. Does anyone have firm data on riding powered up but riding in PAS0? I’ve seen it written that it’s not suggested to ride without some assist but I don’t understand that logic if there is logic in that . The reason I mention that is because I can ride many of the flatter areas without assist and would like to conserve the battery for no reason other than, “just because”. In my first runout I was wanting to see just how much distance I could get in a full charge, I hit 165.

 

[PCeBiker]

Yep.……… and that’s enough for me. I’ll very infrequently ride it to the limits in one go! I usually ride from 54v to 47v.

I Always fully charged and drained my battery for every ride and was suffering from depression resulting from my range anxiety.

I spent many months fussing about trying to attach a second battery to my e-bike.
First it was on my rear rack, but it caused a speed wobble/shimmy when I rode no-hands and I'm all about riding no- , so I spent a month trying to balance and true my wheels, then the 14# battery broke the rack off my ebike.

So after another couple months, I used polymorph plastic to make battery brackets for a second battery on my top tube,..

I finally had the freedom to ride as long and far as I want at full throttle (32 kph), without having to even look at my display.

I could ride full speed into a 30 kph headwind maxed out at 21 amps then turn around and get a free ride home at full speed using less than 2 amps.


I thought it would be smart to do a range test on my newest battery, (48v 25ah) so on my first ride with the two batteries, I rode my e-bike full snort to check the range.

I was getting a little tired after about 2 hours so I decided to head for home and only use the second battery to just get me the rest of the way home after my first battery was completely dead.

Finally, after about 70 km the battery went into the red and shut down on me.

I went to swap batteries to get me the last 11 km back home and realized that I didn't have the damn key for the battery lock with me !!

I removed it from my Keychain because I only use it at home, and I would always charge my battery on the e-bike anyway, so I didn't need to use the key.

Luckily I was running full snort with a Huge Voltage sag, so I had a volt or so to use if I kept the power below 150 Watts and I pedaled along to help.
Then 100 Watts, then 50, then the controller shut me down for the last time with about 6 km of unassistance, pedaling a ~90# e-bike left to go.


Sooo,..
I decided that I would burn the rubber off the head of my key, grind down it down to a nub, and glue it into my keylock,..

The head of the key is still big enough to grab and rotate the spring lock, and I can remove it if I ever need to and use my other key, but it won't fall out of the lock by accident, and I won't forget or lose my key.
(And I didn't glue the lock shut. )

I never leave my e-bike unattended, so I don't need to lock the battery.

They're gunna have to steal the whole damn bike with me on it to get my e-bike and battery.

 

[Jeremy McCreary]

Does anyone have firm data on riding powered up but riding in PAS0? I’ve seen it written that it’s not suggested to ride without some assist but I don’t understand that logic if there is logic in that . The reason I mention that is because I can ride many of the flatter areas without assist and would like to conserve the battery for no reason other than, “just because”.

Have no data for your ebike, but it's OK and generally pretty easy to ride my 38 lb Specialized Vado SL mid-drive with the motor off. And more and more, I've been doing just that in my local mix of hills and rolling coast roads.

Why? (a) Partly "just because", like you. (b) Partly for the exercise. And (c), partly cuz the battery's only 320 Wh, and I don't want to carry or shell out $450 for a 160 Wh range extender till I start hitting the 60+ miles/ride mark.

But there's also a more practical reason: Specialized warrants the main battery for 300 "charging cycles", roughly meaning a total of 300 x 320 Wh added. So the fewer Wh/mile I burn on average, the more main battery miles I'll get under warranty, and the less reason to lug around that heavy extender just to spare the main.

 

[Chargeride]

When riding throttle only I use the time for a good gauge, over two hours and Im monitoring throttle response.
You get a feel for that sudden drop in acceleration that means theres 5 miles left, and thats at reduced speed.
I think the most I ever got out of my DH hub drive running 2KW was 36 miles gunning it everywhere on dirtbike trails.
15ah battery or in Stefan units 750wh.

Riding legal speeds on the road no hills, I got 48 miles.

I had no display, you can just 'feel' when shes about to run out

 

[Chargeride]

I Always fully charged and drained my battery for every ride and was suffering from depression resulting from my range anxiety.

I spent many months fussing about trying to attach a second battery to my e-bike.
First it was on my rear rack, but it caused a speed wobble/shimmy when I rode no-hands and I'm all about riding no- , so I spent a month trying to balance and true my wheels, then the 14# battery broke the rack off my ebike.

So after another couple months, I used polymorph plastic to make battery brackets for a second battery on my top tube,..


View attachment 189231



I finally had the freedom to ride as long and far as I want at full throttle (32 kph), without having to even look at my display.

I could ride full speed into a 30 kph headwind maxed out at 21 amps then turn around and get a free ride home at full speed using less than 2 amps.


I thought it would be smart to do a range test on my newest battery, (48v 25ah) so on my first ride with the two batteries, I rode my e-bike full snort to check the range.

I was getting a little tired after about 2 hours so I decided to head for home and only use the second battery to just get me the rest of the way home after my first battery was completely dead.

Finally, after about 70 km the battery went into the red and shut down on me.

View attachment 189232



I went to swap batteries to get me the last 11 km back home and realized that I didn't have the damn key for the battery lock with me !!

I removed it from my Keychain because I only use it at home, and I would always charge my battery on the e-bike anyway, so I didn't need to use the key.

Luckily I was running full snort with a Huge Voltage sag, so I had a volt or so to use if I kept the power below 150 Watts and I pedaled along to help.
Then 100 Watts, then 50, then the controller shut me down for the last time with about 6 km of unassistance, pedaling a ~90# e-bike left to go.


Sooo,..
I decided that I would burn the rubber off the head of my key, grind down it down to a nub, and glue it into my keylock,..


View attachment 189233


The head of the key is still big enough to grab and rotate the spring lock, and I can remove it if I ever need to and use my other key, but it won't fall out of the lock by accident, and I won't forget or lose my key.
(And I didn't glue the lock shut. )

I never leave my e-bike unattended, so I don't need to lock the battery.

They're gunna have to steal the whole damn bike with me on it to get my e-bike and battery.

I did exactly the same, but was using xt90, so just taped the second battery in place

 

[PCeBiker]

I did exactly the same, but was using xt90, so just taped the second battery in place

I wasn't in any real danger of being stranded it the middle of nowhere because the battery brackets for the Reention dorado battery are junk, and so are the ends of the battery case.
(Although I have faith in the cells and BMS inside my three cases.)

So I would have just smashed the lock/bracket if I had to.

My battery bracket broke on my first e-bike by the end of third ride when I finally thought to find the source of the clunking noise I was hearing.

It was the broken battery bracket letting the battery bounce around.
I damn near lost the battery,..

So I rebuilt it using Krazy Glue, the graphite from ½ dozen pencils, and cotton string pulled from my jeans,..

Then I bought a new pair of battery brackets as well,..
(They're crap so I was stocking up. )

Then I bought a new 48v 25ah battery with Samsung 50E cells for $840 CAD and managed to blow the damn thing up within 10 minutes of it arriving at my door.

I wanted to check the shipping Voltage and managed to short the battery output with a big crack of lightning 🌩.


With the help of the battery vendor, I managed to get the battery going, but not until after I opened it up to investigate.

Then of course I overtightened the tiny screws and all 8 of them broke through the plastic battery cap, but not of course till after my first ride.

,.. so just taped the second battery in place

So I just taped the battery caps to the case, with lots of RTV silicone (color matched of course) and it's been working fine for almost two seasons now with over 5000 km on it pulling my lazy ass around.

I used the fancy Permatex RTV Silicone and Gorilla tape for the job.
I didn't want to put dollar store tape on an $800 .

I shudda read the label before I started playing with it.

 

[spokewrench]

Doesn't anyone have "estimated range" display?

My Aventon Abound displays remaining percent. It seems to work better than voltage. 100 to 90% would give me about the same distance as 50 to 40%.

For more than a year, those readings indicated a range of 250 to 300 miles, but I've been 30 miles since my last charge, and it still reads 99%. That indicates 3,000 miles to a charge. I no longer use motor assistance on hills unless of course I'm chasing a car with a beautiful woman. My independence started a month ago when I began buying lentils instead of pintos. Go figure!

 

[PCeBiker]

Doesn't anyone have "estimated range" display?

@PedalUma mentioned a guy that had a Huge e-bike with two enormous batteries on board.
The guy left his house with fully charged batteries and his ebike was saying he had either a 100 or 200 mile estimated range.
He only made it about 10-20 miles before the batteries were dead.
But, he was riding 30 mph into a 30 mph headwind.


I was riding my e-bike on the pavement with the throttle locked using ~200 Watts, then I went onto the gravel shoulder and my Watts went to over 350 Watts, then onto the grass beside the gravel shoulder and my power went to over 450 Watts.

On my motorcycle, the most that I could reduce my mpg/range was less than 50%, and I had to triple my speed from 50 kph to 150 kph to do it.

On an e-bike, it doesn't take much at all to drastically reduce your range, so if you are on a ride and you're estimated range says that you are at 50%, so you turn around and head home, but decide to ride through grassy fields to get home, you're not going to make it.
The computer will start recalculating as soon as you hit the grass, but it won't take long before it tells you that you're not going to make it home.

Easy to check hypothesis; ride it and see how much further you go.

Familiarize yourself with how your ebike runs, A lithium battery is nonlinear. You get far more miles for 54-to-48V than from 48-to-40V. Just go out and ride it.

^^^ What they said.
You just have to get a feel for your e-bike.

 

[PCeBiker]

For more than a year, those readings indicated a range of 250 to 300 miles, but I've been 30 miles since my last charge, and it still reads 99%.

Can you reset your computer or get it to recalculate or something?

30 miles using 1% of your charge doesn't make sense, and your computer should know that.

I HATE AI !!

I think Artificial Intelligence is unnaturally stupid.

 

[Roamers]

The computer will start recalculating as soon as you hit the grass, but it won't take long before it tells you that you're not going to make it home.

The beauty of estimated range (ours is in miles) is you can adjust what you are doing to do what you want. If I'm running relatively flat with minimal assist and the range says 60 miles, when I kick it to max assist going up a hill and it drops to 22, I can make a decision on my next move. Getting off high assist back to level, range goes back to 45 and life is good.

 

[spokewrench]

Can you reset your computer or get it to recalculate or something?

30 miles using 1% of your charge doesn't make sense, and your computer should know that.

I HATE AI !!

I think Artificial Intelligence is unnaturally stupid.

These days the power demand is more lights than motor time, and I guess LED lights don't need much.

A gator's fast-twitch fibers make it powerful and lightning fast, but if you wrestle one long enough, it's so helpless that you have to be careful not to drown the poor thing. Its fast-twitch fibers turn glucose into lactate, which causes an oxygen deficit in the blood.

I didn't want to drown like a gator, so when I'd feel a lactate buildup while wrestling my bike up a hill, I'd call for motor assistance. After more than 4 years of several miles a day, lactate buildup was suddenly not a problem. Humans have slow-twitch, and a lactate shuttle can feed lactate to the slow twitch, which use it for fuel instead of letting it cause an oxygen deficit. Can lentils enable a lactate shuttle?

 

[PCeBiker]

The beauty of estimated range (ours is in miles) is you can adjust what you are doing to do what you want. If I'm running relatively flat with minimal assist and the range says 60 miles, when I kick it to max assist going up a hill and it drops to 22, I can make a decision on my next move. Getting off high assist back to level, range goes back to 45 and life is good.

OK, that makes sense. It sounds really user friendly.

Computerization usually pisses me off, but that sounds really useful, and more accurate than my approach.

I watch the needles and can see the power demand as it's happening in real time, but I still have to guesstimate my range.

What I don't like about digital is how all the numbers can turn into a blur.

54.6 looks Way Too Much like 56.4, and when it comes to lithium batteries, it could mean the difference between a fully charged battery, and a fully burnt house.

 

[Roamers]

OK, that makes sense. It sounds really user friendly.

I'm a retired Engineer, anal (not really a-hole) is my middle name. When we jump on the bikes I want to just ride and not have to think about anything, just enjoy nature!

 

[PCeBiker]

,.. I guess LED lights don't need much.

It depends on how many you've got and how bright they are.
I've got 500 Watts happening in my closet,..

I need to wear a welders helmet to water my plant.

,.. Its fast-twitch fibers turn glucose into lactate, which causes an oxygen deficit in the blood.

I worked with a guy that was a competitive runner who said that you could take Alka-Seltzer or Rolaids before a race to help neutralize the lactic acid and stop the pain in your muscles and joints, but if you were caught, you were kicked out of the race for cheating. (doping)

I don't know how they could check for that?
Maybe every runner had to give a vomit sample before the race?

 

[PCeBiker]

I'm a retired Engineer, anal (not really a-hole) is my middle name.

I was supposed to be an electrical engineer but didn't finish college.
Oddly enough, I took electronics engineering technology- computer systems, but I Hated computer class.

I wanted to build circuit boards and computers, not sit behind a screen punching on a keyboard.
It was 1985 and not too many of us could afford a home computer, so we had to stay after school to do our homework and sign up to get a computer.

I remember "writing" a test on the computer, then we had to fax it () to the teachers computer.
I got the results back and scored 40% !!??
My damn computer only sent half my test to the teacher for some unknown reason that even the teacher couldn't figure out, but luckily he found my other half of the test with a time stamp on it, lost out in space somewhere and rescored my test.

I'm a retired Engineer, anal (not really a-hole) is my middle name.

I can't stop being anal (and a jackass) myself but that really is a stupid word.
I know it's short for analytical, but they really should find a replacement.

I checked the thesaurus and it ain't much better and the antonym is just as bad,..

I hear that prune juice helps if you're anal retentive.

When we jump on the bikes I want to just ride and not have to think about anything, just enjoy nature!

I'm the same. I've actually turned my display facing down to help me stop compulsively looking at it.

I'm way better now that I'm carrying two batteries.
I can waste all the electrons I want and my batteries will always outlast me and my sore ass.

 

[Roamers]

I'm the same. I've actually turned my display facing down to help me stop compulsively looking at it.

I continually watch cadence, periodically check heart rate and range.

 

[PCeBiker]

I continually watch cadence, periodically check heart rate and range.

It was the Watt meter for me, followed by the voltmeter.
I was pretty OCD about it.

Now it's checking my mirror instead.
But that's a good compulsion.
2 or 3 times this year I was riding down the middle of a gravel road, no-hands, and checked my mirror to see a car 10 feet behind me.

They were nice enough to not blare their horn at me though.

 

[PCeBiker]

I continually watch cadence,

I'm always aware of my cadence, but it's easy to count to zero.
I occasionally rotate the crank 180° to sit on my other butt cheek.

 

[6zfshdb]

The best way I've found to estimate range is to keep track of the wattage used as you ride. This eliminates the non linear voltage factor.

I use a gauge which can be programmed for total battery capacity and counts watt hours consumed. In addition to a % remaining display, it has a 10 segment bar graph indicating the charge remaining. Through experimentation, I know exactly how many miles I get per bar. It's completely linear and the first bar yields exactly the same number of miles as the last, under the riding conditions I most frequently use..

https://www.amazon.com/gp/product/B0BBV95BYL/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

It also displays real time voltage & current. It isn't elegant but it's the most accurate method I've found.