My Kona Smoke 29'er

[Russell]

Within minutes of getting the battery set for action I was on the road. This was going to be a short shakedown run over a familiar 18 mile course with the goal being to push hard and find any problems right away. I did want to limit capacity used to 5Ah of the 10Ah rating and at the end of the ride the Watts Up meter said I used 4.998 Ah! The trip average speed was a record for me and my Bafang at 20.8 mph compared to a best average speed of 20.1 mph with the 6Ah Fatpacks boosted by a 9Ah SLA (actual about 4.8Ah). The little 250W motor felt stronger throughout the ride and there wasn’t the big voltage drop-off near the end like with the Fatpack/SLA combo.

So after one ride I was satisfied. The only thing I didn’t see was any increase in top speed on the flats. While the LiFePO4 battery comes off the charger at 59.3V that top charge is burned off very quickly so that within minutes the battery is under 54V or about where the 36V LiMn Fatpacks + 12V SLA would start. The nearest level stretch is the first half-mile of a bike path I pick up 4 miles from home and on that I still got a top speed of approximately 23.5 mph.

After this first ride the battery charged back up in just under 2 hours. I left it on the charger for another 45 minutes after the indicator went green then went for another ride. This ride was to be a longer 31 mile route that I’ve done many times. The goal this outing was to pedal easier than usual and let the motor pick up the slack but I still wanted to at least match my normal 18.0 mph average speed for the route. Usually I have to conserve battery power on this route so I pedal moderately and use a light throttle on the fist 20 miles then pick up the pace the last 11 miles. With the extra capacity of the 10Ah battery I didn’t have to worry about running out a few miles from home which was a nice feeling. For this ride I averaged 18.7 mph and used 6.412 Ah. The average power used per mile was a gluttonous 10.5 Wh/mi compared to my usual 7.5 Wh/mi over the same route at 18.0 mph with the previous smaller pack. Power does corrupt


-R

[bikeelectric]

Russel,
I like how you put that plastic food container in your Topeak bag to take up the extra space. I carry my lunch to work in that space in a plastic container like that.
A few observations since I got my Cycle Analyst. On my 48V 10 AH Headway pack using Nine Continent motor, I can cruise between 26 to 28 MPH on flat or going up a moderate hill. My range is about 18 to 20 Miles with no pedaling and going full blast on the throttle. The other day I went for a much longer ride and kept the speed to bike trail cruising well under 20 MPH and I got 26 miles and 9.8 AH out of the pack before low voltage disconnected me.

[Russell]

Russel,
A few observations since I got my Cycle Analyst. On my 48V 10 AH Headway pack using Nine Continent motor, I can cruise between 26 to 28 MPH on flat or going up a moderate hill. My range is about 18 to 20 Miles with no pedaling and going full blast on the throttle. The other day I went for a much longer ride and kept the speed to bike trail cruising well under 20 MPH and I got 26 miles and 9.8 AH out of the pack before low voltage disconnected me.

What are your trip average speeds? The speeds I quote for a given distance are always the average speed shown on my computer for the entire ride.

Do you have a picture of the Headway pack in your Topeak bag?

The battery I purchased is a generic 1C type so nowhere near the class of the Headway but 48V/10Ah with a 15A controller is about all the Bafang can handle (see next post).

-R

[Russell]

Day 2 of Life with LiFePO4

Yesterday I got in two rides, an 18.4 mile fast ride using 5Ah and a second longer 31.2 mile ride using 6.4Ah. The battery handled those without a glitch therefore today I wanted to crank it up a notch to use somewhere between 7 and 8Ah of the battery’s rated 10Ah capacity.

I rode west further than normal out to a small city where I lived a couple of years ago. The ride there was great because I had a tailwind which of course is always nice…until you have to turn around and ride into it. I had only used 2.5Ah in 21 miles so I needed that headwind if I was going to use as much of the battery capacity as I wanted to. With a combination of more speed, more throttle and the headwind I ended up using twice the energy in the second half of the ride as the first. In the end the WU meter showed 7.486Ah (381.8Wh) consumed over the 41.4 miles at an average speed of 17.7 mph. The last 20 miles I used 5Ah which is over an average of 250W for the last hour. This is the hardest I’ve ever pushed the 36V 250W Bafang and it was definitely HOT. I could hold my hand on the motor but it was rather uncomfortable to do so for very long.

After 3 progressively longer rides the battery is looking good so far. Buying a generic battery with now no one at the other end to support it is risky so I'm keeping a battery log with all of the trip data. The thing I'm looking at most closely for these first cycles is the "minimum voltage" (Vmin). Thus far the Vmin has been 48.67V, 48.86V and 47.84V for the 5Ah, 6.4Ah and 7.5Ah rides respectively.

-R

[bikeelectric]

This is from my cycle analyst from the ride in to work this morning going full throttle and just about no peddling .
4.8 miles
max speed 30 avg speed 20
2.7 AH
137 watt hours
28 watts/mile

What are your trip average speeds? The speeds I quote for a given distance are always the average speed shown on my computer for the entire ride.

Do you have a picture of the Headway pack in your Topeak bag?

The battery I purchased is a generic 1C type so nowhere near the class of the Headway but 48V/10Ah with a 15A controller is about all the Bafang can handle (see next post).

-R

[Russell]

Today was another in a string of exceptionally nice days we've had this September but this is Wisconsin and that can change overnight so I figured a nice long ride was in order. I donned my lycra shorts instead of the usual baggies and grabbed two big water bottles. Just three miles out I hear BANG! and the back end drops. I stop and there's a puddle of green goo oozing from the flattened tire. I don't know what I ran over or if it was just something that was waiting to happen but looking at the gaping wound in the tire I knew this ride was over. I don't carry anything specifically to cope with a failure like this one because it's never happened before but I did have some electrical tape to reinforce the tire a little. Anyway I put the spare tube in and inflated it but I knew I couldn't ride it far like this so I started hoofing it home. After 1.5 miles I got tired of walking and figured I'd try riding it, and this is where the motor came in real handy. I got up on the pedals and leaned forward over the front wheel, unweighting the rear tire, and just motored home I'm sure I jinxed myself by stating in another post just a few days ago the tires were wearing very well after 1,400 miles. Oh well now I can order those new Schwalbe Supremes

Kona 033.jpg (82.54 KiB) Viewed 1889 times

-R

[WonderProfessor]

I am no expert on tires, but from the appearance of that tire, if you had run over some object that caused that rupture, you would have either seen what you run over. That looks like a failure with the tire itself.

[StudEbiker]

Russell, do you have a thread on that power switch you built? That looks really sweet. I need to make something like that for the 9c kit, and that looks perfect.

[Russell]

I am no expert on tires, but from the appearance of that tire, if you had run over some object that caused that rupture, you would have either seen what you run over. That looks like a failure with the tire itself.

I think you're right about that and in a way I would better if it was a tire failure than if it was caused by a road hazard. I rode the identical route on my second ebike right after the incident and again today and didn't see anything, or hit anything, in the road that could cause it. The tire was fully inflated too so it would be hard for an object to rip the tire open like that while riding down a suburban street.

I can't find an exact replacement for the Continental City Contact 700x47 so I'll buy two new tires. I'm going to hate shelling out $100 for a pair of Schwalbe Supremes but I want them

-R

[Russell]

Russell, do you have a thread on that power switch you built? That looks really sweet. I need to make something like that for the 9c kit, and that looks perfect.

No but I talked about it here;

http://www.endless-sphere.com/forums/viewtopic.php?f=2&t=9407&start=15#p163313


-R

[WonderProfessor]

I'm going to hate shelling out $100 for a pair of Schwalbe Supremes but I want them

-R

Good tires are worth every penny! For me, I would pay almost any amount to get bicycle tires that performed as well as steel-belted, radial automobile tires. When was the last time you had a flat tire while driving your car? I absolutely hate flats. They steal your time, your most precious commodity!

[Russell]

I decided to splurge and ordered a pair of Schwalbe Marathon Supremes (28x2.0, 700Cx50) to replace the Continental City Contact tires (700Cx47) since I couldn't find an exact replacement for the one blown tire. The Continentals with a perfectly smooth, hard 1cm center section may have rolled faster, I'm not sure, but the Supremes are wonderfully comfortable tires, they absorb shock far better than the Continentals and handle great too.

Schwalbe1.jpg (95.17 KiB) Viewed 1041 times

I don't care too much for the reflective stripe on the sidewall so I darkened it with a Sharpie and close up it looks sort of purple but further away it's not real noticeable, it also still reflects light as you can see below in the non-flash Vs. flash pictures. I did prefer the look of the Continental's since their logo matched the yellowish Kona decals but whatcha gonna do.

Schwalbe3.jpg (177.66 KiB) Viewed 1044 times

One other change I made to the bike in the search for comfort was adding a Cardiff Wessex leather saddle w/ springs. I ordered this before I received the Schwalbes because I didn't think the tires alone would offer as much improvement as they have. I'm not sure I care for the saddle however. I've only been on two rides with it and it's not broken in yet but I just can't get comfortable on it, nor can I keep up a good spin rate on it. I think like the original Kona saddle it's too wide for my bum. Oh well I can always sell it on eBay.

Cardiff saddle1.jpg (92.39 KiB) Viewed 1013 times

-R

[WonderProfessor]

I've only been on two rides with it and it's not broken in yet but I just can't get comfortable on it ...

That's because the original design for upright bicycle seats was taken from various torture devices built in the Dark Ages.

For the life of me, I can not understand why recumbents are not more popular.

[adrian_sm]

For the life of me, I can not understand why recumbents are not more popular.

A friend of mine has a Lotus Elise. Beautiful car. But you have to be really defensive when driving it. Being so low tall vehicles don't see it, they see over the top of it.

I feel a bit the same about recumbents, the lower ride height would get me more nervous on the roads with cars. They have a hard enough time noticing a normal upright bike.

[GASSTINKS]

Those tires look great, as does the entire bike. When my pair of Marathon Plus wear out (I've got at least 2,000 miles on them currently without any flats), I'll try a pair of those 700x50 Supremes. Not sure if they would fit in my frame, though.

About upright bike vs. recumbent visibility: I've ridden both and can attest to the fact that you're just as INVISIBLE on an upright bike to drivers. HIgh-vis clothing, flashing led lights, and neon dummy flags help a bit, but not much. Most of the time I'm cut off by drivers it seems as if they are making a deliberate choice to ignore I'm in the bike lane beside them. Helps to have good brakes.

[WonderProfessor]

... about recumbents, the lower ride height would get me more nervous on the roads with cars. They have a hard enough time noticing a normal upright bike.

Sigh. Yet another myth propagated onward toward bicycling eternity ...

Recumbents are actually more visible than uprights. They are still odd enough that motorists notice them more than upright bikes. I can not tell you how many times motor vehicle operators have swerved towards me trying to get a better look. In the 1990's, drivers would pass me, stop their cars and get out to ask me about the bike. It is different now that recumbents are far more prevalent but they still are enough of an oddity to get themselves noticed. The low height is a red herring unless it is one of those very low trike recumbents where the rider is almost lying on his or her back. In this case, a large flag is warranted.

Disclaimer: The above does not apply when the motorist is either (1) driving with their eyes diverted to either [a] a mobile electronics device, [b] a newspaper or other reading material, [c] a porn flick displayed upon their illegally installed video monitor, or [d] the nearest sexually-explicit billboard advertisement. It also does not apply if they are (2) slapping their ill-behaved children, or (3) applying make-up, or (4) driving while under the influence of recreational pharmaceuticals, or (5) any number of numerous other tasks that motorists believe are far more important than the immediate task at hand, i.e. operating their motor vehicle.

Whether upright or recumbent, please be vigilant.

P.S. Recumbents are actually far more safer than uprights. You can not fly over the handlebars of a recumbent. The center of gravity is much lower and the weight is distributed more toward the rear wheel. Rather, you will fall sideways. A broken hip is far less deadly than a broken neck.

P.P.S. Recumbents also are faster and more efficient than upright bikes. Recumbents are banned from bicycle races because there is simply no contest between riders of like ability. The rider on the recumbent will far out pace the rider on the upright.

P.P.P.S. And no, they are not hard to peddle up hills! What you do is gear down and spin faster. I have seen many recumbent riders sprint up hills quickly. (Not me. My knees are more important than my pride.)

P.P.P.P.S. Dontcha' just hate sanctimonious forum posters that do not know when to quit showing off their knowledge of a topic most cyclists don't want to hear about?

[dogman]

A recumbent could be invisible, behind or beside another car. So if you are hiding behind the car, how are you seeing what is on the other side? I wouldn't call that the bike's fault, but the bike rider. You can pop out from behind a van and get killed on a regular bike just as easy.

Riding out in the streets, being predictable to the cars is very important to saving your life. But on a regular bike, wearing yellow, I still get right crossed regularly when I want to cross a crosswalk going straight ahead with the crosswalk light saying walk. Makes you want to carry a flag on a 10 foot pole to wave under their noses. Hey, guy using the crosswalk with the signal saying walk here! They still don't see you even when you have been parked side by side for about 3 minuites.

[Russell]

36V revisited

Ever since I purchased a 48V/10Ah LiFePO4 battery I’ve turned into something of a power hog using as much as 66% more energy per mile as I once did when I rode my first E-bike early this year. Back then I could stretch a 36V/9Ah SLA pack (5.4Ah usable) to 32 miles. When I switched to using 3 Bosch Fatpacks (~6.4Ah max) I got a little faster and used slightly more energy but I was still able to stretch the little pack out to 32 miles and once even 37 miles, admittedly with a conservative throttle but still using the motor to assist at least 80% of the time. Back then it was pretty easy to run in the 6-7 Wh/mile range since the Bafang on 36V wasn’t capable of high speeds. Still even when I added a 12V SLA in series with the Fatpacks I was able to keep energy use in the 7-8 Wh/mile range while boosting average speed by at least 1 mph. Again since the SLA would die at just over 4.7Ah I needed to conserve most of the time. Much of that restraint flew out the window when I got the 48V/10Ah battery and ever since I’ve been using power in the 10-11 Wh/mile range with that dipping to 9 Wh/mile only on longer than normal rides. The 10-11 Wh/mile range isn’t bad but that’s because there is still one tiny thing holding me back…the Bafang motor. If I were to use full power all of the time I’d not only probably consume double the power, I’d send the poor little Bafang to a premature grave from over-heating.

This brings me to the purpose of today’s ride at 36V, to answer the question “could I ride with greater efficiency at 36V…or at all for that matter or had I just gotten lazy”. Anyway the other reasons for the ride at 36V were to discharge the Fatpacks since I don’t know when I’ll use it again this late in the season and because it’s chilly out (47F, 8C) and a slower ride with less wind-chill seemed like a good idea.

The power drop at 36V compared to 48V was instantly noticeable as was the need to use far more throttle. On the plus side, the motor operated more quietly. It didn’t take too long for my internal speed-O-meter to adjust and on the bike path portion of the trip I settled into spinning one gear lower and perhaps 1.5 mph slower than at 48V. With virtually no one else on the path today there were no ‘rabbits’ to pursue or riders approaching from the rear to egg me on either so it was a nice serene ride. Once off the path the wind and grades were more noticeable than at 48V but it wasn’t until I hit the wide open road that the lower speeds felt, well…pokey. The last 4.5 miles of this route is mostly a lightly traveled frontage road with for the most part a 50 mph limit. With the 3 Fatpacks half-empty and an unfavorable wind full throttle and pedaling yielded speeds of 18-20 mph. Generally at 48V I’m flying along this stretch at easily 5 mph faster. I ended the ride at the slowest average speed I’ve done in a long time, 16.4 mph. I have noticed with the advent of colder temps my speed has dropped on the past few rides so it’s partly that. Aside from the lower speed I didn’t make any effort to conserve power using the throttle most of the time to provide some assist and I ran full or near full throttle the last 4.5 miles of the 18.2 mile trip. The end result was 7.96 Wh/mi, not stellar but I have no other rides at 36V on this bike to compare it to at this locale.

After a brief rest and a little snack I loaded up the 48V battery for another trip. I wanted to see what the power consumption would be if I rode the exact same speed over the same route as I had just done at 36V. It took a light touch on the throttle to do it but It seems I had quickly adjusted to the lower speed, in fact due in part to being less fresh than the first ride I found at the half-way point I was running at about a 0.4 mph deficit. No matter once out on the country roads I spun up the legs and the motor to quickly make that up. The challenge was keeping the speed to 18 mph on that last 4.5 miles of open road which took only about half throttle at 48V. A half-mile from home I hit the same average speed as before then just held it there. The result was perhaps not surprising; to cover the same distance at the same speed I used an almost identical amount of power, in this instance 7.78 Wh/mile for 48V compared to 7.96 Wh/mile for 36V. The difference was it was easier to ride slower at 36V, which also should come as no surprise.

Before I purchased the 48V/10Ah battery I went back and forth between it and a 36V/15Ah version. I would likely get better range with the latter but the former is definitely more fun and with a lot of self control it can be ridden at the same speed resulting in lower power consumption per mile.

Oh yeah and the answer to “have I gotten lazier?” is; well perhaps a little but I still come home from each ride sweaty and heck I rode 36.4 miles today and 3,700 miles this year, that’s gotta be worth something.

-R

[sparky]

Hey Russell,

Really interesting test. Thanks!... I, like you, crave the speed of 48V LiFe, so there's no going back. In fact, I'm thinking about adding a booster "turbo button" to mine for a boost for speed on long, flat sections...I'm running a 48V 16Ah Ping v2 and a 72v C'lyte controller. Seems like I should be able to add at least 12V more and still have some overhead for the controller.

For your booster pack, did you use any diodes or anthing like that? Was yours "always on" or did you switch it in (aka turbo button)? Any recommendation for this application? I'd like to use something light, something other than SLAs... thanks!

Scotty
(PS I'm in the Twin Cities...what part of WI are you?)

[kevo]

Russell.

While generally a lurker on endless-sphere, I must say your posts have inspired my ebike ambitions with Bosch 36V packs.
Thank you so much for all your posts and feedback on incredible ebike progress.
-K

[Russell]

Hey Russell,

Really interesting test. Thanks!... I, like you, crave the speed of 48V LiFe, so there's no going back. In fact, I'm thinking about adding a booster "turbo button" to mine for a boost for speed on long, flat sections...I'm running a 48V 16Ah Ping v2 and a 72v C'lyte controller. Seems like I should be able to add at least 12V more and still have some overhead for the controller.

For your booster pack, did you use any diodes or anthing like that? Was yours "always on" or did you switch it in (aka turbo button)? Any recommendation for this application? I'd like to use something light, something other than SLAs... thanks!

Scotty
(PS I'm in the Twin Cities...what part of WI are you?)

I don't so much crave the speed of 48V as I get used to it and anything less feels slow. My 36V Bafang is no speedster at 48V with a top speed of 23.5 mph but it still provides some good assist at 25-26 mph allowing me to ride faster than all but the swiftest of Roadies. On average I don't ride all that much faster on 48V than on 36V but of course any extra speed is all from the motor meaning power consumption rapidly rises with small incremental increases in average trip speed.

My 12V9Ah SLA booster was used in series with a pack made up of 3-36V 2.2Ah Bosch Fatpacks. The Fatpacks do not have a BMS to worry about and of course neither did the SLA so I did not need any protection diodes. Because the capacities were close I simply put them in series. In practice the SLA would die at about 4.7-4.8Ah, well before the LiMn Fatpacks, so while I tried to limit my use to that level I didn't care about getting long life from the SLA's. I got 3 of the SLA's with my first kit and quickly ditched them in favor of the Bosch Pack however using them as a booster was a way to put them to some use.

Today the temps here in Southeastern Wisconsin reached the low 60's and since that's a rarity now I had to get out and ride. I once again chose to ride on the little 36V/6Ah pack all by itself. All it really took was a change in mindset to ride more slowly and for much of the ride I didn't miss the extra voltage, in fact the less hurried pace is more serene especially on the narrow and wooded bike path portion. After a while I found I wasn't using much power so instead of turning for home early as I had planned I continued around my full 31 mile course. In the end I used less power than I have in quite some time, just 6.2 Wh/mile, and still had a thoroughly enjoyable ride, the only difference was the lower average speed of 16.4 mph. I'm wondering now if I should not have gone for the 36V/15Ah pack instead of the 48V/10Ah


-R

[sparky]

... I'm wondering now if I should not have gone for the 36V/15Ah pack instead of the 48V/10Ah


-R

Thanks for the help on the booster!

Let me know if you want to unload your 48V/10 to help you finance a 36V/15....would like to build a bike for my speed freak wife!

[Russell]

I'm wondering now if I should not have gone for the 36V/15Ah pack instead of the 48V/10Ah

-R

Within an hour after writing that line I had purchased a 36V/20Ah battery through eBay. Comprised of 100 small cells and boasting unimpressive specs it would never be my first choice especially at the retail price. My 36V/6Ah Bosch pack however has 60 cells and that works well and besides for $220 delivered it was a pretty good bargain…if it works. Well today the postman delivered it so of course I had to try it out right away. It came with a compact little 2A charger which is woefully underpowered for such a large pack. The pack was already mostly full, I forget the voltage I read, but I put it on the charger for a short time just the same. The charge voltage got up to a wee bit over 42.0V and it wasn’t done yet but I was impatient to ride so I disconnected it. I also opened the charger and dropped the open circuit voltage to 42.0V from 42.4V to go easier on the cells and hopefully extend the life of the pack which the previous owner said had 20-25 cycles on it.

The battery was purchased here by the original owner;

http://www.campsolution.com/li-ionbatterymodule36v88ah288whwithpcbready40x1865010s4p-3.aspx


Here it is packed in my rear Topeak bag;

snug as a bug in a rug

36V20Ah 004.jpg (83.38 KiB) Viewed 1168 times

I hit the road at 11:30 local time on a gray overcast 55 degree day with a brisk wind. The pack voltage started out at 41.9V so while the Bafang was not as fast as with the 48V pack it was still fairly strong. I wanted to test the capacity of the pack but didn’t want to ride forever to do it so for the first 20 miles I used close to full throttle much of the time easily pedaling at 19-20mph. At 25 miles out with 7Ah used already the motor felt noticeably weaker and I started to fret over if I’d even be able to squeeze 15Ah out of the battery. It wasn’t any help that as I turned back I was headed into the wind, it also feels slower on open roads than on trails or suburban streets. At 10Ah used I had traveled 35 miles, definitely not an economy run as I have done over 30 miles on 6Ah(36V). At 38 miles I stopped briefly to scarf down three fun-sized snickers bars (mental note: pick up more candy for trick or treat ). From this point on it was full-throttle at all times. I noted at 13Ah used I was still getting 3 amps of assist at 19 mph, which is meaningless to the reader but told me the battery was actually delivering pretty much what it should at this point. Just before 14Ah used I climbed a short 12% hill and at the top the speed fell to 8 mph with pedaling vs. 11 mph, also with pedaling, with the 48V LiFePO4 pack. I tried shifting to my small chainring but the steel cable had rusted in position from never being used. Two miles from home and I got rained on, not much mind you but it hadn’t warmed up a bit and I was getting a little chilly. When I arrived home I had completed my longest e-bike ride yet at 49.8 miles at an average speed of 17.3 mph and consumed 15.170Ah/570.1Wh. That’s a high 11.45Wh/mile but not unexpected given my limited input, especially on the first half of the trip. The battery resting voltage at the end was 37.22V and that along with the Vmin of 34.66V told me I plenty of juice to spare…maybe even 5Ah????

Come spring I’d like to use this battery for some much longer rides and if I pick a nice day when I’m feeling especially energetic who knows I may even try for a century which should be possible if I would limit power consumption to the low 6 Wh/mi range. For every day use though I think I’ll stick with the 48V/10Ah LiFe battery. While I don’t ride all that much faster with the 48V pack I do like having the reserve to be able to easily spin up to higher speeds. If the weather holds I think I’ll load the 36V/20Ah pack on my Raleigh ebike presently running a 24V GM Mini Motor and heat that puppy up a bit .



-R

[Russell]

The little motor that has never let me down in 3,000 miles up and quit on me today. The only good thing was that it died 4 miles from home instead of 15 or worse during the two proceeding rides which took me as far as 25 miles from home. I have been pushing the motor hard lately and today back on the 48V battery was no exception however the failure itself came swiftly, as I reached the top of a hill the motor simply quit. Applying the throttle resulted the motor making a hammering sound indicative of a hall sensor failure. I was hoping it was a connection or controller problem but alas no the connections were all fine and the motor has the same problem on an identical spare controller but runs on my sensorless unit. Oh well I was planning on taking the Bafang apart for a full inspection sometime during the winter this failure simply moved up that timetable.

-R

[docnjoj]

[quote="Russell"]The little motor that has never let me down in 3,000 miles up and quit on me today."

I am sorry to hear of the motors demise on 48 volts. I really miss the "punch" since I have been on 36 volts, Soon since I have the gears if they get mashed, to repair with 1 steel. I haven't fried a Bafang yet (just the gears) and I ride pretty conservatively for a big guy on a big trike but I was using 20 Ah/mile or more with the 48 volt Ping. Good luck with repairs, Russell!
otherDoc