Off Road Battery Size recommendation for BBSHD

[MoneyPit]

I've also been charging the pack to 90% not 100% I've heard this is supposed to prolong the life of the pack and every 5th charge or so I'll go to 100%. I think that is supposed to balance charge the pack. What I don't understand is got the pack down to 11% still read 48v. It's a bit off though my multi meter is reading 48.4v. I've heard keep it above 44v and I should be safe. The vendor said BMS is set to 41v that sounds really low. I wish the EggRider had some sort of audible alarm that's adjustable. So im not really sure where im at other than just continue to monitor the voltage and don't go below 44v?? Or is there something else I should be doing.

Not charging to full capacity does prolong battery life. The usual recommendation is 80%. And even though the info about not charging to full capacity has been out there... forever... still its not widely recognized by consumers. So thats why, I think, you don't hear much about depth of discharge, which is just as bad or worse depending on who you ask.

Scroll down to Table 2:

https://batteryuniversity.com/article/bu-808-how-to-prolong-lithium-based-batteries

A li-ion battery is happiest over the long term if you keep it roughly between 80% and 40%. Roughly. What this means is its better to have a battery thats bigger than you need than it is to carry two of them and drain the bejesus out of them.

With that said, enjoy your bike. Yeah what you are doing may kill the pack sooner, but you could swallow a chicken bone at dinner tonight and thats the end of you. Do what you can within your limits of convenience.

As for battery voltage, they are called '48v' but max charge on such a pack is 54.6v. Here check out these charts and you can see where your 44v and 41v are on the scale.

https://talesontwowheels.com/2019/10/02/li-ion-ebike-battery-charge-charts/

As for balancing, I ride every day and charge to 80% at work in the morning and at home in the evening. Once a month, I do a 100% charge to balance the pack. If I rode less I could do it less frequently. Even what I am doing is just guesswork though. Its not like I am measuring each bank of cells to see if one has gone wonky.

 

[geosped]

I think I would rather get another 8ah or even a 6ah pack. Just swap them out when I deplete one in a safe range. I have a 17ah and for me it's way to big and heavy. I would rather give up some range for a smaller pack and swap them out. But that's just me and it would cost quite a bit more to have two packs.
Another reason I like the smaller packs is it allows me to be very discreet. They are quite a bit smaller and lighter I suppose at the cost of longevity. Most people don't even realize I have an ebike unless they take a second look.

 

[COAR]

With that said, enjoy your bike. Yeah what you are doing may kill the pack sooner, but you could swallow a chicken bone at dinner tonight and thats the end of you. Do what you can within your limits of convenience.

I think this is the best advice. I've spent several hours researching this topic for both my smartphone and e-bike pack and ultimately decided it's not worth it to try and eke out a little extra life. Running an e-bike battery only between 80 & 40% really is not practical for recreation purposes. You can only use half your capacity that way so you're carrying several extra pounds of battery for nothing.

The data sheet for the 40Ts (I think I posted it earlier in this thread) said you can get 250 cycles (and that's probably fully charged to the LVC) before you're at 60% capacity. Personally that's several years of usage so when you amortize the battery cost over that period, it's not too bad.

 

[geosped]

With that said, enjoy your bike. Yeah what you are doing may kill the pack sooner, but you could swallow a chicken bone at dinner tonight and thats the end of you. Do what you can within your limits of convenience.

I think this is the best advice. I've spent several hours researching this topic for both my smartphone and e-bike pack and ultimately decided it's not worth it to try and eke out a little extra life. Running an e-bike battery only between 80 & 40% really is not practical for recreation purposes. You can only use half your capacity that way so you're carrying several extra pounds of battery for nothing.

The data sheet for the 40Ts (I think I posted it earlier in this thread) said you can get 250 cycles (and that's probably fully charged to the LVC) before you're at 60% capacity. Personally that's several years of usage so when you amortize the battery cost over that period, it's not too bad.

Bottom line I'm going to just enjoy it and replace it when it craps out. I'm just going to continue to do what I do. 90% charge and every 5 or so charges do 100%. When it craps out I just get a new one. No point in sweating out the minutia you will never be happy.

People had me worried about the chain line and it was months of hard riding before I got a chance to swap out chain ring. In the end still have the same chain, not a single pop-off all the sprockets teeth dont show any sign of wear and my chain wear indicator is SPOT ON! Just be happy and go riding is what I say.

 

[MoneyPit]

Yeah if what you are doing now works for you. Keep doing it. While doing that you should know the facts about how stuff works... and make decisions on how you proceed based on knowing not guessing. But don't let any of that spoil your riding.

 

[geosped]

Yeah if what you are doing now works for you. Keep doing it. While doing that you should know the facts about how stuff works... and make decisions on how you proceed based on knowing not guessing. But don't let any of that spoil your riding.

I thought that's the whole point of these conversations.

 

[COAR]

COAR, if you do adjust those numbers, let us know how that responds.

I replaced the throttle with the standard universal thumb one and at the same time, changed the voltage to start at 11 and end at 42, with 5% start current. I also changed the throttle level to be fixed at assist level 9.

There's a lot more modulation than I had before (no idea if it's the new throttle or the settings) but it is hard to actually modulate as it's difficult to keep my thumb in a steady position. That might improve with more practice though as I've only had 1 ride with the new setup.

 

[geosped]

COAR, if you do adjust those numbers, let us know how that responds.

I replaced the throttle with the standard universal thumb one and at the same time, changed the voltage to start at 11 and end at 42, with 5% start current. I also changed the throttle level to be fixed at assist level 9.

There's a lot more modulation than I had before (no idea if it's the new throttle or the settings) but it is hard to actually modulate as it's difficult to keep my thumb in a steady position. That might improve with more practice though as I've only had 1 ride with the new setup.

For me what helps is if you adjust the thumb lever closer to the ground that way my thumb has to engage at a lower point. It's just a simple work around and doesnt address the real issues.

 

[MoneyPit]

There's a lot more modulation than I had before (no idea if it's the new throttle or the settings)

The throttle may be a factor but those settings will make the throttle much less of an on/off switch, with exactly the increase in modulation you describe. You'll get better at working it with practice.

I like to have my throttle lever pointing straight down to the ground when it is fully engaged. If I hit a hard bump there is no added thumb pressure on the lever. I'll either be able to hold the lever position or I won't and my thumb will slip off, but it won't come down on the now-fixed lever and potentially snap it off.

 

[TNC]

Throttles are such a preferential issue. Add to that the often touchy nature of the Bafang throttle programming and stuff can be all over the board. COAR, I didn't find the factory Bafang throttle very impressive either. I had both the sideways thumb throttle and the forward push throttle. The forward push throttle felt better but still not great for my taste. I went to the Luna motorcycle grip version because it's more intuitive to a dirt motor guy. With both throttles the delivery is now smooth, but the lack of a "gap" or play before the throttle actually kicks in is not great IMO.

 

[COAR]

So I like the throttle set permanently at 9 however it's a bit of a handful climbing technical trails. Particularly when starting from a stop and there's a bunch of baby heads immediately ahead. I probably look like a novice trying to ride a motorcycle lol. Front tire will lift slightly, bike will surge forward, then stop abruptly once it hits a rock before I have a chance to stand up, balance and start pedaling. I feel climbing technical trails is almost easier with my pedal only 29er. Not sure if it's wheel size related (or throttle modulation), but I feel like I'm relearning how to mt bike with the heavier throttle.

 

[HrKlev]

I feel climbing technical trails is almost easier with my pedal only 29er. Not sure if it's wheel size related (or throttle modulation), but I feel like I'm relearning how to mt bike with the heavier throttle.

Exactly my thoughts and experience as well, and why I think a torque sensor setup is a must for this kind of usage. Hopefully the CYC stealth and lightest.bike kits will turn out to be decent units, as bafang does not seem like they are going to include a torque sensor in theirs bolt-on kits.

 

[raylo32]

I agree that a torque sensor *should* be a better fit for riding technical stuff. But... my new CYC install on the Stumpjumper has a bit of a delay, maybe a half second, between you start pedaling and assist coming in. This is an older short travel bike so I decided to basically retire it from the trails and use it as a road and gravel e-bike. But I have tried a couple of trails... not overly technical but very steep. And I do find the delay to be an issue. It might get better if I rode it more in those situations to get used to the timing. I suspect PAS only bikes have the same issue.

Exactly my thoughts and experience as well, and why I think a torque sensor setup is a must for this kind of usage. Hopefully the CYC stealth and lightest.bike kits will turn out to be decent units, as bafang does not seem like they are going to include a torque sensor in theirs bolt-on kits.

 

[HrKlev]

Ah, thats no good. I had the same problem with my tsdz2 as well. Im sticking with the good, old Cycle Analyst and baserunner system. Very responsive once you get the settings right.

 

[raylo32]

I am not a coder but it seems like the issue would be that they need to prevent motor engagement with torque alone, like if you are stopped with a foot on the pedal. Probably needs a cadence signal in addition and that takes at least a partial rotation of the crank. Not sure how you could ever get rid of all delay.

Ah, thats no good. I had the same problem with my tsdz2 as well. Im sticking with the good, old Cycle Analyst and baserunner system. Very responsive once you get the settings right.

 

[TNC]

So I like the throttle set permanently at 9 however it's a bit of a handful climbing technical trails. Particularly when starting from a stop and there's a bunch of baby heads immediately ahead. I probably look like a novice trying to ride a motorcycle lol. Front tire will lift slightly, bike will surge forward, then stop abruptly once it hits a rock before I have a chance to stand up, balance and start pedaling. I feel climbing technical trails is almost easier with my pedal only 29er. Not sure if it's wheel size related (or throttle modulation), but I feel like I'm relearning how to mt bike with the heavier throttle.

Your comment, "feel like I'm relearning how to mountain bike", isn't far from truth. I think dirt motor folks have an easier time adjusting to a PAS mountain bike or e-throttle, but even for me, a life long off road motorcycle and MTB guy, the application of a power assist on a mountain bike is a bit of an alien experience. Add that to the fact that MTB's don't have the stability of a dirt motor, and it really is something one has to get used to whether a long time MTB'er or dirt motor guy.

If I recall, you and I both have a BBSHD on a real mountain bike, and I think we softened up the throttle tab quite a bit. I really do use my display +/- to go up and down on differing terrain. On the climb in a technical application, I've gone as low as "2" to stop that abrupt jerk during PAS. I have my PAS starting at almost undectable in "1" but going full tilt by "9". But again, these are highly preferential adjustments for each rider and terrain. I guess I'm used to the throttle coming on pretty strong because of my dirt motor experience, but even then you know we've talked about how abrupt it can be as delivered. Mine is softened up quite a bit.

 

[raylo32]

Yeah, this is what I am afraid of. And many of our trails here have these nasty rock gardens where there is not a lot of room for error or "learning". But there are a couple of nice flowy trails without rocks or many significant obstacles like downed trees and such... So I may try those if we get a nice dry spell this fall. I know, I am geezin' but I hate to do muddy rides anymore and have to clean all the crap off and out of the bike. Especially now with a motor.

BTW, mine is a CYC on a real, but older model, Specialized MTB.

Your comment, "feel like I'm relearning how to mountain bike", isn't far from truth. I think dirt motor folks have an easier time adjusting to a PAS mountain bike or e-throttle, but even for me, a life long off road motorcycle and MTB guy, the application of a power assist on a mountain bike is a bit of an alien experience. Add that to the fact that MTB's don't have the stability of a dirt motor, and it really is something one has to get used to whether a long time MTB'er or dirt motor guy.

 

[TNC]

I'm totally with you on the avoidance of mud anymore. I raced my state's enduro circuit for decades and the occasional "mud run" was a nasty requirement. It was hell on equipment, not to mention the rider. MTB's don't fare any better, and let's be honest...it's just not as much fun when you can't rail the corners and get the best traction. We don't have much loamy soil around my area where the perfect match of moisture and traction can make for a fun ride. Occasionally in the Moab area a little moisture actually enhanced the riding...just as long as it wasn't too much...LOL!

On your comments about rocky terrain, I'm finding a little more each day with my SC Nomad and BBSHD. The bike weighs 50 pounds, so I'm getting over the idea of having to pedal every foot of movement when a step-up or baby heads appear. My motor works with my PAS...I hear some don't...so if I hit a rock section that starts to hang me up I hit the throttle. My throttle delivery is still strong enough to give me a bit of that dirt motor boost to clear that particular spot or set of rocks when necessary. I will recommend not to wait too long. I do have 6.5" of travel in the rear and an 8" dual crown fork on front, so I can fairly well hammer nasty spots when necessary.

Another thing I'm finding out that I thought would be a bigger problem is ground clearance. I've been going over some decent rocky areas, and I've been impressed at the lack of bashing the motor. My first ride at one of our places, I kissed the motor, but I've gotten more aware of line choice in regards to the motor and chainring now. It's not as bad as I thought would be the case. As I've mentioned before, the Trek Rail 7 demo bike we have at the shop has maybe a hair less ground clearance than my Nomad. I'm sure my dual crown fork helped with that. When I had a Fox 36 on front, the bikes were equal.

 

[raylo32]

Mine weighs just about 50 pounds, too... maybe a few less. But it is old school 2003 XC model with max 90mm rear travel... which I have set to the lower position of 70mm to keep my oversized tire from hitting. LOL... rear 2.1" tire is oversized only in the sense that the frame is old school and designed to fit 1.95s. So the rocks are quite a challenge. Now 25 years ago I cleaned some of these same rock gardens on a rigid bike but when you are young and stupid you can do stuff like that! I am wiser now (I think) and a whole lot older.

One thing that I won't worry about so much is clearance... my CYC motor tucks up out of the way as compared to the integrated types like Bafang or my bike with TSDZ2. I could see that being a problem here with those in these rock gardens which have randomly distributed rocks of all sizes in all orientations. Often times hit chainrings on rocks and logs. Those motors wouldn't stand a chance.

On your comments about rocky terrain, I'm finding a little more each day with my SC Nomad and BBSHD. The bike weighs 50 pounds, so I'm getting over the idea of having to pedal every foot of movement when a step-up or baby heads appear. My motor works with my PAS...I hear some don't...so if I hit a rock section that starts to hang me up I hit the throttle. My throttle delivery is still strong enough to give me a bit of that dirt motor boost to clear that particular spot or set of rocks when necessary. I will recommend not to wait too long. I do have 6.5" of travel in the rear and an 8" dual crown fork on front, so I can fairly well hammer nasty spots when necessary.

Another thing I'm finding out that I thought would be a bigger problem is ground clearance. I've been going over some decent rocky areas, and I've been impressed at the lack of bashing the motor. My first ride at one of our places, I kissed the motor, but I've gotten more aware of line choice in regards to the motor and chainring now. It's not as bad as I thought would be the case. As I've mentioned before, the Trek Rail 7 demo bike we have at the shop has maybe a hair less ground clearance than my Nomad. I'm sure my dual crown fork helped with that. When I had a Fox 36 on front, the bikes were equal.

 

[COAR]

I'm totally with you on the avoidance of mud anymore. I raced my state's enduro circuit for decades and the occasional "mud run" was a nasty requirement. It was hell on equipment, not to mention the rider. MTB's don't fare any better, and let's be honest...it's just not as much fun when you can't rail the corners and get the best traction. We don't have much loamy soil around my area where the perfect match of moisture and traction can make for a fun ride. Occasionally in the Moab area a little moisture actually enhanced the riding...just as long as it wasn't too much...LOL!

On your comments about rocky terrain, I'm finding a little more each day with my SC Nomad and BBSHD. The bike weighs 50 pounds, so I'm getting over the idea of having to pedal every foot of movement when a step-up or baby heads appear. My motor works with my PAS...I hear some don't...so if I hit a rock section that starts to hang me up I hit the throttle. My throttle delivery is still strong enough to give me a bit of that dirt motor boost to clear that particular spot or set of rocks when necessary. I will recommend not to wait too long. I do have 6.5" of travel in the rear and an 8" dual crown fork on front, so I can fairly well hammer nasty spots when necessary.

I have a BBS02 so a bit less torque but the throttle is great when moving to get a boost of speed to clear rough stuff ahead. It's just jarring from a dead stop though - hard to use it smoothly.

The trails around here generally close when they're muddy, but if not, it's poor etiquette to ride them and leave deep tracks. If I come across a muddy section I'll often walk it - that's half to limit trail damage and half to avoid cleaning (especially nice when I just threw the bike in the back of the SUV). That said CO is pretty dry and the dirt is best after a bit of moisture - we got a touch of rain yesterday and my ride later that day was probably the best the trails have been all year. Went out today for a quick lunchtime ride and the trails were back to their usual dry, dusty condition.

My bike is just under 50lbs with battery and I've gotten used to the weight but it's unavoidable (and very noticeable) in 2 scenarios: loading the bike, and walking it on steep stuff. I had to walk it yesterday on a section that was too rough to climb (and would make for difficult hiking even without a bike) and that was not a fun 25 yards. I tried to use the motor for walking assist but the throttle would just spin the wheel, and while there's a 'walk' function, that's way too awkward to use on hairy terrain.

 

[HrKlev]

I am not a coder but it seems like the issue would be that they need to prevent motor engagement with torque alone, like if you are stopped with a foot on the pedal. Probably needs a cadence signal in addition and that takes at least a partial rotation of the crank. Not sure how you could ever get rid of all delay.

Getting rid of most of the delay you get when you stop pedaling for a brief moment (like avoiding pedal strikes) is very simple. Just add a slight amount of phase current while the throttle is off and motor is not stalled, just enough to keep the drivetrain engaged and the motor spinning. Baserunner/phaserunner has that feature, and I cant understand why it is not more usual. Its such a huge deal for us riding tecnical terrain. As a bonus, you can change gearing without pedaling while bombing down the trail, and the engagement of assist is always smooth without that jerk when the motor catches up. I tried to suggest it in the tsdz2 thread, as it would be a great feature, but not much interest. Maybe it is incorporated in the latest osf now, idk, as I dont have the unit anymore.

The 36 poles in the erider torque sensor makes it quite easy to get enough movement from a standstill, or otherwise the throttle is the only option. If Im in the right gear I dont use it. But yeah, some assist without moving the pedals would be great.

 

[Feraldave]

yes a bafang bbshd...