Sacman
10 kW
I have a BionX PL500 and I'm trying to get a little more torque for hills (primary reason). I'd also like to get just a bit more speed and range. Has anyone tried to overvolt a BionX with another battery pack?
OverVolting a BionX???
- Thread starter Sacman
- Start date
Sacman
10 kW
Hiya Sherm,
The bike is a new 26-inch Schwinn Sidewinder mountain bike I bought at WallMart for $160. It weighs about 32 pounds and has a sturdy metal frame. The tires are not too knobby so it rolls well. The BionX PL 500 kit i got is a rear wheel hub and the Li-Ion battery is mounted to the center of the bike frame where one would normally mount a bottle holder. PL500 kit and bike together both weigh about 65-70 pounds. It's comfortable and very stable with the BionX PL500 on it.
I'm a pretty heavy guy at 290 pounds but the PL500 can cruise me and the bike at 22-24mph at full throttle on level ground (no pedalling). On mild hills of up to 5% grades the speed slows down to about 17-19mph. I'm pretty happy and content with this kind of speed. However, here's the problem... on even steeper hills of 10% grades or better it really doesn't have the power to make it up. This is awful because my commute route to work has big hills with long steep grades of up to 18%. So that's why I'm thinking of trying to overvolt it to get more torque. I'm pretty sure the motor itself can handle it but I'm not so sure about rest of the electronics (the controller and display console).
BTW Sherm, as far as range goes... I got as far as 19 miles (assist level setting at 4 and very little pedalling on my part) before the BionX showed a noticeable loss of power. Well I hope that info helps you decide.
-Sacman
The bike is a new 26-inch Schwinn Sidewinder mountain bike I bought at WallMart for $160. It weighs about 32 pounds and has a sturdy metal frame. The tires are not too knobby so it rolls well. The BionX PL 500 kit i got is a rear wheel hub and the Li-Ion battery is mounted to the center of the bike frame where one would normally mount a bottle holder. PL500 kit and bike together both weigh about 65-70 pounds. It's comfortable and very stable with the BionX PL500 on it.
I'm a pretty heavy guy at 290 pounds but the PL500 can cruise me and the bike at 22-24mph at full throttle on level ground (no pedalling). On mild hills of up to 5% grades the speed slows down to about 17-19mph. I'm pretty happy and content with this kind of speed. However, here's the problem... on even steeper hills of 10% grades or better it really doesn't have the power to make it up. This is awful because my commute route to work has big hills with long steep grades of up to 18%. So that's why I'm thinking of trying to overvolt it to get more torque. I'm pretty sure the motor itself can handle it but I'm not so sure about rest of the electronics (the controller and display console).
BTW Sherm, as far as range goes... I got as far as 19 miles (assist level setting at 4 and very little pedalling on my part) before the BionX showed a noticeable loss of power. Well I hope that info helps you decide.
-Sacman
Bigsherm said:
dogman dan
1 PW
Maybe I have a bad attitude, but because bionx is expensive could it be more sensitive to voltage than the cheapskate wilderness energy stuff I have? The cheap stuff is pretty much one size fits many voltages. Maybe you could just get a geared hub to run at normal voltage with your bionx controller.
Doctorbass
100 GW
biony bike if i remember operate at 10s lithium? so it's 42V when fully charged and 37V nominal.
I think that for holding 42V their controller circuit inside the wheel would need a safe margin form the 42V.. so maybe the capacitors they used is 50V or maybe 63V. I would not go over 50V for ocasional use. first, you should open the motor and see or post close pics of the PCB and we should be able to help about that ! :wink:
Doc
I think that for holding 42V their controller circuit inside the wheel would need a safe margin form the 42V.. so maybe the capacitors they used is 50V or maybe 63V. I would not go over 50V for ocasional use. first, you should open the motor and see or post close pics of the PCB and we should be able to help about that ! :wink:
Doc
silentflight
100 W
The 500 watt Bionx sounds nice.
I "upgraded" a 250 watt Bionx by adding a 4s2p A123 pack for shorter trips. The 24V NiMH battery is near 28V fresh off the charger, and the A123 is 14V so I am running it at 42V for the first few minutes anyway.
Here is a photo showing my first attempt to overvolt using a smaller NiMH pack.
I think it performs at a level similar to a 350 watt Bionx with the A123 pack added.
I will tell you more about how I did it if you want to try it out.
I "upgraded" a 250 watt Bionx by adding a 4s2p A123 pack for shorter trips. The 24V NiMH battery is near 28V fresh off the charger, and the A123 is 14V so I am running it at 42V for the first few minutes anyway.
Here is a photo showing my first attempt to overvolt using a smaller NiMH pack.
I think it performs at a level similar to a 350 watt Bionx with the A123 pack added.
I will tell you more about how I did it if you want to try it out.
silentflight
100 W
I assembled the overvolting packs from cells. The pack in the photo is made of four 8Ah NiMH cells recovered from a used Bionx 24V NiMH battery. The A123 pack cells came from a DeWalt 36V pack I bought on Ebay. A123 are rated at 2.3Ah per cell, I typically get 2.15Ah with a 3.0V low voltage cutoff, so the pack is about 4.3Ah. I use a Watt's Up to keep from running the A123 below recommended voltage. Note that the overvolt pack is only half the 8Ah of the BionX battery, so I would need to make a 4s4p A123 pack in order to get the full use of both batteries together.
Sacman- At first, early last year, I added 1.2V NiMH cells a few at a time to see how high I could go. I was surprised at how much difference just three cells made in the top speed I could achieve. Alright, it wasn't defying the laws of physics, but it put a smile on my face. My extended time cruising speed on a flat road with no wind rose from 18 to 23 mph with the 4s2p A123 pack. It climbs hills more aggressively as well. I have been planning to try this someday on a 350 or 500 watt BionX. You could end up with the world's baddest BionX with a 48V PL500HS.
You only need to open the battery case and snip one of the heavy gauge wires coming off the internal battery pack. Solder some Dean's wet noodle wire onto each end of the wire you cut and run them back out of the bolt hole the way I did. I did have to cut off a small plastic piece which normally forms a cylinder around the bolt to get enough room tho thread the wires out as shown in the photo. Pretty minor stuff for a major improvement. Use a voltmeter to make sure you have the polarity correct, and plug in the overvolt pack when you're ready for more power.
While experimenting last year, I found that a 5s2p 17.5V A123 pack would cause the display console to show strange things and power would cut in and out, I guess 45.5V was a little too much for the 24V system. I also found that engaging regenerative braking while using any overvolt pack could cause the BionX to stop assisting, but cycling the power brought everything back to normal. As mentioned by others, regen makes a nice brake, but isn't much use for extending range, so I just keep it turned off.
Perhaps someone here knows how I could achieve a constant flow of 42V to my BionX system, even while my pack voltage drops off during discharge. I notice the difference when the combo pack drops down 3V or so after the first mile. It is steady after that, but I would really like to keep it at the performance I get at 42V. Raising the pack voltage overall wont work because it causes the BionX to act strangely as mentioned above. Is the only solution to build a 48V A123 pack and buy a DC to DC voltage converter that would output 42V from a 42-48V input? Anyone know if such a thing is available and how much it would cost? Could the converter keep the output at 42V even while the input side dropped down from 48V at full to around 42V when empty?
Belated happy birthday wishes to DoctorBass!
Sacman- At first, early last year, I added 1.2V NiMH cells a few at a time to see how high I could go. I was surprised at how much difference just three cells made in the top speed I could achieve. Alright, it wasn't defying the laws of physics, but it put a smile on my face. My extended time cruising speed on a flat road with no wind rose from 18 to 23 mph with the 4s2p A123 pack. It climbs hills more aggressively as well. I have been planning to try this someday on a 350 or 500 watt BionX. You could end up with the world's baddest BionX with a 48V PL500HS.
You only need to open the battery case and snip one of the heavy gauge wires coming off the internal battery pack. Solder some Dean's wet noodle wire onto each end of the wire you cut and run them back out of the bolt hole the way I did. I did have to cut off a small plastic piece which normally forms a cylinder around the bolt to get enough room tho thread the wires out as shown in the photo. Pretty minor stuff for a major improvement. Use a voltmeter to make sure you have the polarity correct, and plug in the overvolt pack when you're ready for more power.
While experimenting last year, I found that a 5s2p 17.5V A123 pack would cause the display console to show strange things and power would cut in and out, I guess 45.5V was a little too much for the 24V system. I also found that engaging regenerative braking while using any overvolt pack could cause the BionX to stop assisting, but cycling the power brought everything back to normal. As mentioned by others, regen makes a nice brake, but isn't much use for extending range, so I just keep it turned off.
Perhaps someone here knows how I could achieve a constant flow of 42V to my BionX system, even while my pack voltage drops off during discharge. I notice the difference when the combo pack drops down 3V or so after the first mile. It is steady after that, but I would really like to keep it at the performance I get at 42V. Raising the pack voltage overall wont work because it causes the BionX to act strangely as mentioned above. Is the only solution to build a 48V A123 pack and buy a DC to DC voltage converter that would output 42V from a 42-48V input? Anyone know if such a thing is available and how much it would cost? Could the converter keep the output at 42V even while the input side dropped down from 48V at full to around 42V when empty?
Belated happy birthday wishes to DoctorBass!
Hi Silentflight, interesting post. I have a PL-250 and already after day 2 the "need" for more power and longer range is growing.
Just so I follow you - you connected the two battery packs in series. Not sure what the Watts up is doing, is it necessary?
What would happen if I connected a normal 12V 10Ah motorcycle battery in series with the Bionx 24V? I'm assuming both speed and range would improve, but I'd be interested in learning how the two batteries will drain over time.
Just so I follow you - you connected the two battery packs in series. Not sure what the Watts up is doing, is it necessary?
What would happen if I connected a normal 12V 10Ah motorcycle battery in series with the Bionx 24V? I'm assuming both speed and range would improve, but I'd be interested in learning how the two batteries will drain over time.
silentflight
100 W
I think the direction I took in this thread means it now belongs in the "E-bike Technical" section. Perhaps it should be moved, though I am not the OP and am not really sure what is appropriate.
Anyway, TorAtle, I hope you are enjoying your new Bionx. I did connect the two batteries in serial, and the Watt's Up is only reading the voltage of the A123 overvolting pack. I use it to monitor how many Ah have been used and the pack voltage. That way I can unplug it before I run it too low and possibly damage the cells.
I am guessing the battery you are thinking of using is SLA, but whatever chemistry, it would basically give you a 36V system. Many others on this forum are experts on SLAs, I am not one of them. I do believe that SLAs are designed for a shallow depth of discharge, so you may only get 5 Ah out of a 10 Ah battery. In that case, like my current setup, your overvolting pack would run low before your main Bionx battery.
You would definitely notice better top speed, more aggressive hill climbing, and some increase in range depending on how fast you go if you add an overvolting pack. I think a very nice overvolt pack for a 24V Bionx would be a 4s4p A123. You will need to have a separate charger for it, though. In order to focus on getting more range, adding some cells in parallel would be the thing to do, or just carry a second pack on longer trips. Any battery can power a BionX despite some of the posts floating around that say that it is a closed system. Once you get down to the cells it doesn't know what's pushing the electrons so you could build a pack that suits your needs.
Anyway, TorAtle, I hope you are enjoying your new Bionx. I did connect the two batteries in serial, and the Watt's Up is only reading the voltage of the A123 overvolting pack. I use it to monitor how many Ah have been used and the pack voltage. That way I can unplug it before I run it too low and possibly damage the cells.
I am guessing the battery you are thinking of using is SLA, but whatever chemistry, it would basically give you a 36V system. Many others on this forum are experts on SLAs, I am not one of them. I do believe that SLAs are designed for a shallow depth of discharge, so you may only get 5 Ah out of a 10 Ah battery. In that case, like my current setup, your overvolting pack would run low before your main Bionx battery.
You would definitely notice better top speed, more aggressive hill climbing, and some increase in range depending on how fast you go if you add an overvolting pack. I think a very nice overvolt pack for a 24V Bionx would be a 4s4p A123. You will need to have a separate charger for it, though. In order to focus on getting more range, adding some cells in parallel would be the thing to do, or just carry a second pack on longer trips. Any battery can power a BionX despite some of the posts floating around that say that it is a closed system. Once you get down to the cells it doesn't know what's pushing the electrons so you could build a pack that suits your needs.
Sacman
10 kW
Thanks for the replies guys. I've actually abandoned the BionX PL500 kit and went with the Crystalite Journey kit and I'm much happier with it. It doesn't have the fancy display/controller as the BionX and it doesn't have the 4 levels of adjustable assist but it does have a same thumb throttle and Pedal Assist mode. One of the best things I liked was that it was less than half the price of the BionX ($750 instead of $1850). But for my ebike purposes in commuting to work and getting into better shape, it just gets the job done.
The Crystalite kit is not as fast as the BionX 500 (cruises on flats at 18-19mph instead of 22-23mph) but it sure climbs hills noticably much better. So I gess this Crystalite kit would be more equivallent to the BionX 350 kit. Both are 36v systems and I believe both have hub motors rated at 500watts.
But my original question about overvolting is still valid here, although I want to do it to my 36v Crystalite kit instead of the 36v BionX. I would be a lot more cautious about overvolting the BionX because the display/controller is much more expensive to replace than the Crystalite controller if I fryed it. But I'm only trying to overvolt it from 36v to 48v which is only a 33% increase. What Doctorbass said about being a safe margin makes sense. And what Silentflight actully doing the overvolting from 24v to 42 (which is actually 75% increase) and it working fine for him leads me to believe I can do it safely too.
Silentflight your idea of using the A123 pack as an test overvolt pack is the best idea I've heard to try out to see if the system can handle overvolting to 48v safely before I go investing more money and upgrading my 36v NiMH battery to a lighter weighing 48v lithium iron phosphate battery pack.
Thanks again guys.
The Crystalite kit is not as fast as the BionX 500 (cruises on flats at 18-19mph instead of 22-23mph) but it sure climbs hills noticably much better. So I gess this Crystalite kit would be more equivallent to the BionX 350 kit. Both are 36v systems and I believe both have hub motors rated at 500watts.
But my original question about overvolting is still valid here, although I want to do it to my 36v Crystalite kit instead of the 36v BionX. I would be a lot more cautious about overvolting the BionX because the display/controller is much more expensive to replace than the Crystalite controller if I fryed it. But I'm only trying to overvolt it from 36v to 48v which is only a 33% increase. What Doctorbass said about being a safe margin makes sense. And what Silentflight actully doing the overvolting from 24v to 42 (which is actually 75% increase) and it working fine for him leads me to believe I can do it safely too.
Silentflight your idea of using the A123 pack as an test overvolt pack is the best idea I've heard to try out to see if the system can handle overvolting to 48v safely before I go investing more money and upgrading my 36v NiMH battery to a lighter weighing 48v lithium iron phosphate battery pack.
Thanks again guys.
silentflight
100 W
I hope you will give us a ride report based on your experience with the Crystalite pedal-assist system. I have wondered how it compares and what differences there might be which only a rider would notice.
As far as overvolting goes, it does have a pretty high cool factor, but I think when possible a new purchaser should buy a system that will fit their needs out of the box. I like to play around with batteries and soldering irons, and I got my system second hand after the warranty had expired, so the level of bravado was not quite so high. Nonetheless I do think that overvolting is a great way to make a machine which may otherwise not exist on the market. For example the 48V BionX system which I think would be about as much fun as can be had on a bike.
Also for anyone considering doing this I want to repeat that I started by adding one NiMH cell at a time, an increment of 1.2V at each step. Now, you may think, and probably rightly so, that when electronics break they just go spark! bang! poof! and I might as well just go straight for the jugular and try my intended final voltage. As it was, however, the system did start to behave erratically at or above 43V or so, so I was able to find the limit without bringing down the system.
Please note as well that 42V is fresh off of the charger and that quickly falls below 40V under a load.
As far as overvolting goes, it does have a pretty high cool factor, but I think when possible a new purchaser should buy a system that will fit their needs out of the box. I like to play around with batteries and soldering irons, and I got my system second hand after the warranty had expired, so the level of bravado was not quite so high. Nonetheless I do think that overvolting is a great way to make a machine which may otherwise not exist on the market. For example the 48V BionX system which I think would be about as much fun as can be had on a bike.
Also for anyone considering doing this I want to repeat that I started by adding one NiMH cell at a time, an increment of 1.2V at each step. Now, you may think, and probably rightly so, that when electronics break they just go spark! bang! poof! and I might as well just go straight for the jugular and try my intended final voltage. As it was, however, the system did start to behave erratically at or above 43V or so, so I was able to find the limit without bringing down the system.
Please note as well that 42V is fresh off of the charger and that quickly falls below 40V under a load.
Cheers Silentflight,
so you can basically use any battery type - and the resulting discharge characteristics would be a combination of the two. I was using a motorcycle battery as an example since I have several of them lying around...I appreciate that they are not the best in terms of power/weight.
Here's some pictures of my bike: http://picasaweb.google.com/toratlelAV/Bionx. I've done 130kms the last week, all on a single gear - ratio 2.75:1. That's higher than most single-speeders use, but with a BionX it's about right. The motor is a bit noisy @ low rpms though...
Happy with the kit so far. I am using the bike much more than before, saving the planet and having fun at the same time
so you can basically use any battery type - and the resulting discharge characteristics would be a combination of the two. I was using a motorcycle battery as an example since I have several of them lying around...I appreciate that they are not the best in terms of power/weight.
Here's some pictures of my bike: http://picasaweb.google.com/toratlelAV/Bionx. I've done 130kms the last week, all on a single gear - ratio 2.75:1. That's higher than most single-speeders use, but with a BionX it's about right. The motor is a bit noisy @ low rpms though...
Happy with the kit so far. I am using the bike much more than before, saving the planet and having fun at the same time
Will
100 mW
From reading about others overvolting their hub motors, the C-lytes take it in stride, yet above 48v there appears to be diminished returns, though this may be from wind friction more than motor input/output. But, even Bionx may have undervolted their efficient and light motors a tad. Seems the PL250 would benefit from a 36v battery just as the PL350 would be perfect for 2 24v batteries in 48v series :? What I'd love is to compare the PL250 w/ standard 24v to the PL250 w/ a 36v battery. Would it performance be close to the PL350 with the same energy input? I've never heard of anyone doing that, but how hard can it be to splice a larger battery in line with it? What is the most popular Bionx forum? I gotta find out. Later 
almostblue
1 µW
- Joined
- Jul 30, 2008
- Messages
- 2
hello and thank you very much for taking the time to share!
I was thinking you would place this in-line with the motor's feed
as it might be a better option for those with units still under warranty.
But on revisiting it the reason for your design is obvious - going in-line to the feed would require a second throttle.
But it would seem that you could keep the system fully modular and could disconnect at will, sort of like a nitrous oxide booster in a car
I mean the flat SAE connector (similar to a trailer's brake light disconnect)
http://solarseller.com/291a96920.jpg
http://en.wikipedia.org/wiki/SAE_connector
http://solarseller.com/low_voltage_dc_pumps__lvm__teel__accessories__plugs_and_extensions.htm
thank you in advance!
I was thinking you would place this in-line with the motor's feed
as it might be a better option for those with units still under warranty.
But on revisiting it the reason for your design is obvious - going in-line to the feed would require a second throttle.
But it would seem that you could keep the system fully modular and could disconnect at will, sort of like a nitrous oxide booster in a car
I mean the flat SAE connector (similar to a trailer's brake light disconnect)
http://solarseller.com/291a96920.jpg
http://en.wikipedia.org/wiki/SAE_connector
http://solarseller.com/low_voltage_dc_pumps__lvm__teel__accessories__plugs_and_extensions.htm
thank you in advance!
