Multiple (mounted) Batteries - No Parallel or Parallel?

[CdnShaun]

Hello Friends,

I get to start my first thread since joining and looking for experience/feedback from those who have installed batteries in parallel on their ebikes.

Currently I have Bionx powered bikes and multiple batteries (errr, 7 of them). When I go for long rides I simply carry the extra batteries with me, swap them on the downtube mount and pedal on. I have no choice of course with these propriety motors and batteries, but I made it work.

A summer project I'm considering would be to build out a bike with 2WD and 4 batteries. The motors/controllers would be from ebikes.ca (9C's and Phaserunners) and the batteries would be 4 identical 52V units, still finalizing that choice.

To start, while I know it's possible to charge in parallel (been doing lots of research on this) that is not my plan. I will charge each battery with it's own charger. I do understand with parallel configurations you want the batteries to be matching voltages (within 0.1V, no more than 0.5V is what I have read) when you parallel the discharge connections connected to the controllers/motors.

I would also be installing a breaker to each controller/motor for safety and the ability to disconnect from the battery/batteries when needed.


I see 3 possible configurations and here are my initial newbie thoughts on each:

1 - No Parallel
Because I would be building out a 2WD setup I would start with 2 of the 4 batteries connected. Half way through the ride I would manually switch to the second battery for each controller/motor. I realize the individual motors may draw more (rear versus front most likely) and may have to change the battery for the rear over ahead of the doing the same for the front - any thoughts would be appreciated.

Pros
-Simplicity. Plug and Play.
-Never work about State of Charge. If the batteries are mis-match they will work just fine with this configuration.

Cons
-Miss out on the better balance of having multiple batteries working together drawing down from their full charge.
-Having to swap connections mid ride. If there is an issue with a battery, will not discover until a long way from home possibly. (Yes the 2WD configuration gives some piece of mind for this however)
-Less balance draw down between the 2 motors, if one motor draws more/needs more Ah's over the distance of the ride.

When I build this bike up I will start of course in this configuration and see how it works. This thread is to gain feedback from others with experience to help me plan for this project.

2 - Full Parallel
All 4 batteries in parallel connected to the 2 controllers/motors.

Pros
-One big system, fully automated while riding.
-Battery draw down balance no longer an issue - both motors sharing all 4 batteries worth of capacity for the ride.
-Most accurate reading on the Cycle Analyst as it monitors the voltage of the 4 batteries operating together as one.

Cons
-Parallel connecting 4 batteries after recharging.
-Most complicated to troubleshoot if there is issues.

3 - 2 x 2 Parallel
While riding today I realized I could actually consider separate parallel batteries, one per motor controller.

Pros
-Still achieve all 4 batteries in parallel configurations (no connection swapping mid-ride)
-Easier to troubleshoot than Full Parallel.

Cons
-Still have to parallel connect batteries managing them like full parallel.

At first when I thought of the 2x2 it gave a sense of less complicated but now writing it out feels like a 'half way' solution stuck in the middle. I wanted to include it though for discussion and feedback regardless as I appreciate those who post and will help me decide what to do.


Those are my thoughts. As you can see there is really no wrong configuration persay, rather I'm just seeking the guidance of those who have done this before me to help determine which configuration would be best to plan for long term.

Thanks again for reading and look forward to the replies.

Cheers
Shaun

 

[john61ct]

Best is all one bank from start to finish of the ride.

Flexibility in sizing your Ah for the ride with paralleled sub-pack is great if that varies a lot.

No reason to do normal charging separately, but no harm other than cost.

Balancing however should be done individually.

 

[CdnShaun]

Best is all one bank from start to finish of the ride.

Flexibility in sizing your Ah for the ride with paralleled sub-pack is great if that varies a lot.

No reason to do normal charging separately, but no harm other than cost.

Balancing however should be done individually.

Thank you!

I do realize that I can save weight on shorter rides by removing the extra batteries when not needed and keep that in mind. That said if I get used to the weight of the batteries as a group I can secure them better to the bike and only remove them for maintenance.

I have considered charging the batteries in parallel as well but been cautioned by a couple friends who have more experience than I...even with each battery having a BMS. I understand the concept that charging them in parallel should keep them at the same voltage just like discharging them in parallel - again I'm here to learn from those who have done all of this before me and I appreciate.

One note related to this is most of the batteries I am considering have separate discharge and charge ports on each. I can parallel up the charge ports (separate of the parallel connections of the discharge ports) for charging if that will work well and keep the batteries at matching voltages - still learning/looking into this concept?

Thank you,
Shaun

 

[goatman]

volts is speed, what happens when you run 2 motors at different voltages

 

[markz]

volts is speed, what happens when you run 2 motors at different voltages

Try it out here
https://www.ebikes.ca/tools/simulator.html?bopen=true

edit - Use the "Add" button on the System B side. Not sure what you'd feel riding with 2 motors running at different speeds on one throttle.

 

[amberwolf]

I get to start my first thread since joining and looking for experience/feedback from those who have installed batteries in parallel on their ebikes.

Some threads with useful info (there are lots of considerations depending on parts used). Not all threads are relevant, but you can tell from the titles whcih should be.
https://endless-sphere.com/forums/search.php?keywords=parallel*+batter*&terms=all&author=&sc=1&sf=titleonly&sr=topics&sk=t&sd=d&st=0&ch=300&t=0&submit=Search
There's more info out there too, but not as easy to find.

If you want the easiest to *use*, then wiring all packs in parallel with switches to disconnect charge and discharge ports as as a set will do that. (so you can disconnect all charge ports from each other except when charging, and disconnect all discharge ports from each other except while discharging, and to disconnect all from each other at both ports when not in use, to prevent any possible issues).

If you use batteries that have the same port for charge and discharge, then no switches are necessary, and complete parallel wiring works just fine, and is the very simplest setup of all.

If you want the easiest to *setup*, then completely independent usage, just swapping packs as you empty them, will do that.

 

[CdnShaun]

I get to start my first thread since joining and looking for experience/feedback from those who have installed batteries in parallel on their ebikes.

Some threads with useful info (there are lots of considerations depending on parts used). Not all threads are relevant, but you can tell from the titles whcih should be.
https://endless-sphere.com/forums/search.php?keywords=parallel*+batter*&terms=all&author=&sc=1&sf=titleonly&sr=topics&sk=t&sd=d&st=0&ch=300&t=0&submit=Search
There's more info out there too, but not as easy to find.

If you want the easiest to *use*, then wiring all packs in parallel with switches to disconnect charge and discharge ports as as a set will do that. (so you can disconnect all charge ports from each other except when charging, and disconnect all discharge ports from each other except while discharging, and to disconnect all from each other at both ports when not in use, to prevent any possible issues).

If you use batteries that have the same port for charge and discharge, then no switches are necessary, and complete parallel wiring works just fine, and is the very simplest setup of all.

If you want the easiest to *setup*, then completely independent usage, just swapping packs as you empty them, will do that.

amberwolf - big thanks for this reply. Your search link provided is much more accurate then what I had tried previously and the results are super helpful.

I have lots to think about now while I wait for my batteries to arrive.

Thanks!
Shaun

 

[john61ct]

I have considered charging the batteries in parallel as well but been cautioned by a couple friends who have more experience than I...even with each battery having a BMS

BMS means many functions.

Best to understand each separately.

1. balancing

With a good pack, there is no need to balance every charge cycle, with some once a month or even longer is fine.

Balancing does not require a BMS, in fact most do a very poor job when the pack starts to require it more frequently.

2. HVC
Charging can safely be done in parallel, so long as the whole-pack termination point is not causing any cell/group to go over your chosen max setpoint.

A single BMS can monitor all the sub-packs, so long as your connection scheme connects each of their respective cell/groups together

3. LVC - That BMS can also prevent any one cell/group from going too low while discharging

There is no need for each sub pack to have their own BMS.

In fact it makes everything more complicated thus less reliable.

But if you do go that way, you must use a single port BMS design in order to parallel charge.

You do **not** want to disassemble your pack for normal cycle charging, only for occasional testing, maintenance like balancing.

 

[CdnShaun]

I have considered charging the batteries in parallel as well but been cautioned by a couple friends who have more experience than I...even with each battery having a BMS

BMS means many functions.

Best to understand each separately.

1. balancing

With a good pack, there is no need to balance every charge cycle, with some once a month or even longer is fine.

Balancing does not require a BMS, in fact most do a very poor job when the pack starts to require it more frequently.

2. HVC
Charging can safely be done in parallel, so long as the whole-pack termination point is not causing any cell/group to go over your chosen max setpoint.

A single BMS can monitor all the sub-packs, so long as your connection scheme connects each of their respective cell/groups together

3. LVC - That BMS can also prevent any one cell/group from going too low while discharging

There is no need for each sub pack to have their own BMS.

In fact it makes everything more complicated thus less reliable.

But if you do go that way, you must use a single port BMS design in order to parallel charge.

You do **not** want to disassemble your pack for normal cycle charging, only for occasional testing, maintenance like balancing.

Thanks John!

The only question I really have left, perhaps you could share - is the experience with the discharge port. Let me explain:

With my plan to install a 60V/50amp breaker between each PhaseRunner and the battery connection I finalize on, my understanding is if I connect a single battery to each PhaseRunner, let's say it has XT90 connections for discussion, because the breaker is flipped there should be little to no spark in the XT90 connection - thoughts?

Once connected I flip the breaker back and complete the connection to the PhaseRunner and off I go. The Breaker is both a switch and protection against a dead short is why I'm considering them.

Same suggestion as above, but now multiple batteries connecting into parallel. With each battery at 0.1V or less delta, will there be much/any spark when the XT90 connections are made? Note the PhaseRunner controller would be disconnected via the breaker.

Of course I will be able to experience all of this in a couple weeks when my batteries arrive - just thought to ask here in this thread to learn more ahead of time.

Many thanks for your thoughts and feedback.

Cheers
Shaun

 

[CdnShaun]

I get to start my first thread since joining and looking for experience/feedback from those who have installed batteries in parallel on their ebikes.

If you want the easiest to *use*, then wiring all packs in parallel with switches to disconnect charge and discharge ports as as a set will do that. (so you can disconnect all charge ports from each other except when charging, and disconnect all discharge ports from each other except while discharging, and to disconnect all from each other at both ports when not in use, to prevent any possible issues).

Hello amberwolf,

Quick question - do you have any suggestions/links to examples of the switches you speak of?

Thank you,
Shaun

 

[amberwolf]

With my plan to install a 60V/50amp breaker between each PhaseRunner and the battery connection I finalize on, my understanding is if I connect a single battery to each PhaseRunner, let's say it has XT90 connections for discussion, because the breaker is flipped there should be little to no spark in the XT90 connection - thoughts?

Correct.

Same suggestion as above, but now multiple batteries connecting into parallel. With each battery at 0.1V or less delta, will there be much/any spark when the XT90 connections are made? Note the PhaseRunner controller would be disconnected via the breaker.

You shouldn't see a spark.

 

[amberwolf]

If you want the easiest to *use*, then wiring all packs in parallel with switches to disconnect charge and discharge ports as as a set will do that. (so you can disconnect all charge ports from each other except when charging, and disconnect all discharge ports from each other except while discharging, and to disconnect all from each other at both ports when not in use, to prevent any possible issues).

Quick question - do you have any suggestions/links to examples of the switches you speak of?

The breakers you're already going to use would do it. They make ganged breakers (or you can gang them with a bar across their toggles) with independent poles, so you can use one ganged breaker on the charge port, and one on the discharge port.

Otherwise, you just need switches rated for the full current you'll be putting thru them. As long as you don't have any voltage potential across the switches (everything at same state of charge) then it doesn't matter what their voltage rating is. If there is any voltage potential expected then you need a switch rated for that voltage, or else just like with breakers, the arcing that can result could just weld the switch (or breaker) shut, so it cannot be switched off at all. They also make ganged switches.


But I would recommend using batteries with the same port for charge and discharge, because then you *also* have battery protection against overcharge by regen braking (as unlikely as this ever is), and because it greatly simplifies the wiring and reduces the number of system failure points.

You can also connect both front and rear controllers to each other at the battery connection, and thus to all the batteries at the same time. This is how both my CrazyBike2 bike and SB Cruiser trike, both 2WD hubmotors, are setup. This allows the battery pack as a whole to supply power easier to whichever controller needs more, with less load on any one battery in the pack.

 

[CdnShaun]

With my plan to install a 60V/50amp breaker between each PhaseRunner and the battery connection I finalize on, my understanding is if I connect a single battery to each PhaseRunner, let's say it has XT90 connections for discussion, because the breaker is flipped there should be little to no spark in the XT90 connection - thoughts?

Correct.

Same suggestion as above, but now multiple batteries connecting into parallel. With each battery at 0.1V or less delta, will there be much/any spark when the XT90 connections are made? Note the PhaseRunner controller would be disconnected via the breaker.

You shouldn't see a spark.

Thank you! This helps so much. I look forward to sharing my experience when my batteries come in. I'm saving the details as a bit of a surprise for when it's actually done and working (don't want to get ahead of myself) and hopefully it works out as I designed it.

Big thanks amberwolf!
Shaun

 

[CdnShaun]

If you want the easiest to *use*, then wiring all packs in parallel with switches to disconnect charge and discharge ports as as a set will do that. (so you can disconnect all charge ports from each other except when charging, and disconnect all discharge ports from each other except while discharging, and to disconnect all from each other at both ports when not in use, to prevent any possible issues).

Quick question - do you have any suggestions/links to examples of the switches you speak of?

The breakers you're already going to use would do it. They make ganged breakers (or you can gang them with a bar across their toggles) with independent poles, so you can use one ganged breaker on the charge port, and one on the discharge port.

Otherwise, you just need switches rated for the full current you'll be putting thru them. As long as you don't have any voltage potential across the switches (everything at same state of charge) then it doesn't matter what their voltage rating is. If there is any voltage potential expected then you need a switch rated for that voltage, or else just like with breakers, the arcing that can result could just weld the switch (or breaker) shut, so it cannot be switched off at all. They also make ganged switches.


But I would recommend using batteries with the same port for charge and discharge, because then you *also* have battery protection against overcharge by regen braking (as unlikely as this ever is), and because it greatly simplifies the wiring and reduces the number of system failure points.

You can also connect both front and rear controllers to each other at the battery connection, and thus to all the batteries at the same time. This is how both my CrazyBike2 bike and SB Cruiser trike, both 2WD hubmotors, are setup. This allows the battery pack as a whole to supply power easier to whichever controller needs more, with less load on any one battery in the pack.

Last quick question if I may, when you have a few moments to share your thoughts.

On connecting multiple batteries at once I have learned of several options. The breakers connected together as a unit in a housing of some kind, wiring harness that daisy chain the batteries together, bus bars to centrally connect everything, etc.

What did you find work best for you?

I have found some bus bars that are cost effective and on paper look like a great solution - 150 amp and 100 V rated (called the tech support to discuss and confirm) - which would allow me to connect all batteries with equal length connections and then the controllers/motors as well all cleanly to the bus bars for a clean installation/design....but again, all new to me and hence my research and preparing to carefully test and test some more any design I go forward with.

Thank you amberwolf!
Shaun

 

[amberwolf]

I'm saving the details as a bit of a surprise for when it's actually done and working (don't want to get ahead of myself) and hopefully it works out as I designed it.

FWIW, "saving the details" often ends up meaning that those trying to help dont' have all the information necessary to help you make the correct decisions. Lots of poeple do this sort of thing, and end up with stuff that either doesn't quite do what they expected or wanted, or doesn't work at all. '

Hopefully that won't be the case here, but almost every time someone tells us that, especially *after* they've made decisions and bought things based on recommendations made with the incomplete information, they're not as happy as they could've been.

 

[amberwolf]

On connecting multiple batteries at once I have learned of several options. The breakers connected together as a unit in a housing of some kind, wiring harness that daisy chain the batteries together, bus bars to centrally connect everything, etc.

What did you find work best for you?

That entirely depends on your specific equipment, conditions, design intent, usage scenario, DIY capabilities, budget, etc.

For my stuff, you can see the stuff I've done in my build threads, but basically since my budget is usually zero, I end up hacking old bits of things together to make what I want. Often reusing old powerchair wiring, connectors, and breakers, because its' the heaviest duty stuff I could get for free (or close to it). Housing would just be screwed down into the wooden compartmetns or deck/ etc of the trike, or bolted or clamped inside the old metal enclosures of previous bieks, or even just hose-clamped to the bike frame in the open, since it's almost always very dry here, and water intrusion is not a huge consideration except a few days of the year (when it literally floods and nothign really stops the water from getting in *somewhere* if I have to ride in it.)

In my case, the controllers are mounted under the deck near the motor wheels. The battery is inside the cargo seatbox, with the breaker and the cutoff switch a few inches away, but with over a foot of wire between them all. The controls are on the handlebars. The relays that control power and lighting and the DC-DC to help with that are in the "triangle" behind the front wheel.

If I were to buy all new stuff, and build a new trike completely from scratch with all new materials, with parts made (by someone else because I don't have the capability) for the purpose, it'd probably be very different.


So where your stuff is located and how it's laid out helps determine what you use, and how you use it. For instance, if you have a regular "mountainbike" sort of bike, and the batteries are on panniers on either side of the rear wheel, typical busbars cna't be used because they are usually uninsulated straight flat bare metal bars, and you don't want battery voltages exposed like that. Instead, you would use insulated cables, of appropriate gauge for the system's expected current, vs the layout of the cabling. Either two equal-length sets of cables from the batteries up to your single breaker and switch and controller setup, or a single set of cables from one battery to the other, and *then* a longer thicker cable from that one up to the rest. Or a breaker on the cable from each battery, etc.

If instead you have one battery on a rear rack, and another on a downtube, and the controller inside the motor wheel, you could run the downtube battery cables from it to the rear rack battery, and then from there a thicker cable to a box with teh switch/breaker/etc, and then to the contgroller. Or to the box frm both batteries, etiher separate breakers for each or just one for both, then to controller.

If instead you have both btteries in a singel box on the rear rack, you could then use busbars to connect them, and to the breaker/switch/etc, then cable to the controller.

Lots of ways of wiring it, depending on layout.

I have found some bus bars that are cost effective and on paper look like a great solution - 150 amp and 100 V rated (called the tech support to discuss and confirm) - which would allow me to connect all batteries with equal length connections and then the controllers/motors as well all cleanly to the bus bars for a clean installation/design....but again, all new to me and hence my research and preparing to carefully test and test some more any design I go forward with.

Busbars dont' actually have a voltage rating. They can carry a million volts, if they are spaced far enough apart, and/or insulated sufficiently. So you would have to ask the place what that voltage rating is supposed to mean.

The current rating *is* important, as it indicates how much they might heat up if used beyond those ratings (a resistance per mm or inch would be useful, or a crosssection measurement and a material type, that you can then lookup and calculate, if necessary). Because "150A' only works for a certain length of the material--if you had one a foot long, it might be ok, but if you have one that's 10 feet long it could be quite a heater with significant voltage drop, at that current.

But if you have a Bionx system, it doesn't draw nearly that much current (maybe 20-30A for the highest powered stuff I've seen), so stuff rated that high is way overkill. With the Phaserunners, they still dont' draw huge currents so 150A stuff is probably still overkill, depending on your exact setup and usage scenario. Overkill is fine, if you prefer large safety margins, but usually unnecessary. I personally prefer overkill vs close margins, but that's because I tend to keep pushing things harder and harder until they break.

 

[CdnShaun]

amberwolf, you are a wealth of information. Thank you so much for taking the time to reply.

I see what you mean by sharing details to get better help. So here goes,

The donor bike:
https://surlybikes.com/bikes/big_dummy

Building out a Surly Big Dummy Cargo Bike. 9C DD Hub motors front and rear for 2WD, PhaseRunner for each motor mounted in the the triangle space in front of the rear tire, Cycle Analyst with the new 2020 Grin Tech 2-to-1 cable to properly control the dual PhaseRunners.

Batteries will be 2 or 4 or 6 in total, mounted in a custom built frame/box on the back of the bike, equal amounts on each side by the wheel to keep the weight as low and close to the frame.

As mentioned with the 2WD/Dual controllers if I end up with just 2 batteries then it's either single battery per controller (simplest) or parallel to share the battery capacity to the two controllers, advantage is one controller can pull more watts over the total ride, the CA will be more accurate as it will be measuring the combined battery capacity remaining (not just one of the 2), etc.

If I go with 4 or 6, then the choice of swapping connections mid-ride or wiring them in parallel as shared in the initial posts above. I will build a frame for the the wiring and breakers to be contained safely within for protection from impact and occasional rain if I get caught in it unexpected. In this framed space I could safely install bus bars, such as blue sea bus bars with insulating caps on top and again, secured space preventing any accidental impact that could cause a short.

All cable lengths as you can see now are normal length/short in length with the only long runs would be a) to the CA and b) from the front PhaseRunner to the Front motor.

As for the bus bars - yes they can go really high in Voltage, sorry I miss spoke - the tech support gave me the all clear for up to 100V without any concerns as I as asking about this build and possible future builds. Like you he suggested to be safe and the 150 Amp models for my planned 20-60amp draw (10-30amps per phaserunner) would be extra safe was his thoughts and I tend to agree.

So yup, that's it - Cargo bike with lots of Go Go juice for all day riding. I'm having a blast learning new all over again (I know Bionx inside/out but sadly they cannot give me what I want now) and again, super appreciate your time to reply in this thread.

Cheers!
Shaun

 

[amberwolf]

Building out a Surly Big Dummy Cargo Bike. 9C DD Hub motors front and rear for 2WD, PhaseRunner for each motor mounted in the the triangle space in front of the rear tire, Cycle Analyst with the new 2020 Grin Tech 2-to-1 cable to properly control the dual PhaseRunners.

Batteries will be 2 or 4 or 6 in total, mounted in a custom built frame/box on the back of the bike, equal amounts on each side by the wheel to keep the weight as low and close to the frame.

If you use the xtracycle sideloaders you can build your batteries into the "decks" along with the rest of the electronics. There is a build here that does that, but I can't find it now because I can't remember which bike it was based on. :/

EDIT: This one is simlar, but it's not the full-metal deckplating version, so not the same build:
https://endless-sphere.com/forums/viewtopic.php?f=3&t=33337

This build
https://endless-sphere.com/forums/viewtopic.php?f=6&t=36959
is very well documented, and has some stuff you might consider.

There's some other similar bike frames used as cargo bikes here:
https://endless-sphere.com/forums/viewtopic.php?f=6&t=26413
and here:
https://endless-sphere.com/forums/search.php?keywords=yuba*&terms=all&author=&sc=1&sf=titleonly&sr=topics&sk=t&sd=d&st=0&ch=300&t=0&submit=Search
that may give you ideas.

There's more under xtracycle, and of course under the Surly versions, edgerunner, etc.

As mentioned with the 2WD/Dual controllers if I end up with just 2 batteries then it's either single battery per controller (simplest) or parallel to share the battery capacity to the two controllers, advantage is one controller can pull more watts over the total ride, the CA will be more accurate as it will be measuring the combined battery capacity remaining (not just one of the 2), etc.

I would use single-port (same for charge and discahrge) batteries, and I would have all batteries paralelled together, as well as the controller battery inputs. It's the simplest setup, as it lets you use just one shunt for the CA to monitor, and all batteries supply power at the same time to everything, and receive power at the same time during regen (making it easier on the BMS charge fets to accept the regen).

You can install breakers on the output of each battery, so you can isolate any of them if necessary.


Keep in mind the CA doesn't really measure battery capacity "remaining". It measures current passing thru the shunt, and counts that over time, to show Ah / Wh used up. As long as you know the actual capacity / charge state the batteries start a ride out at, that works fine. It also has a battery indicator icon that can be relatively useful, but isn't perfect, as it mostly works on voltage (but not completely).

All cable lengths as you can see now are normal length/short in length with the only long runs would be a) to the CA and b) from the front PhaseRunner to the Front motor.

The stuff ot the CA is not power-carrying, it's just data lines, so not important.

 

[CdnShaun]

Building out a Surly Big Dummy Cargo Bike. 9C DD Hub motors front and rear for 2WD, PhaseRunner for each motor mounted in the the triangle space in front of the rear tire, Cycle Analyst with the new 2020 Grin Tech 2-to-1 cable to properly control the dual PhaseRunners.

Batteries will be 2 or 4 or 6 in total, mounted in a custom built frame/box on the back of the bike, equal amounts on each side by the wheel to keep the weight as low and close to the frame.

If you use the xtracycle sideloaders you can build your batteries into the "decks" along with the rest of the electronics. There is a build here that does that, but I can't find it now because I can't remember which bike it was based on. :/

EDIT: This one is simlar, but it's not the full-metal deckplating version, so not the same build:
https://endless-sphere.com/forums/viewtopic.php?f=3&t=33337

This build
https://endless-sphere.com/forums/viewtopic.php?f=6&t=36959
is very well documented, and has some stuff you might consider.

There's some other similar bike frames used as cargo bikes here:
https://endless-sphere.com/forums/viewtopic.php?f=6&t=26413
and here:
https://endless-sphere.com/forums/search.php?keywords=yuba*&terms=all&author=&sc=1&sf=titleonly&sr=topics&sk=t&sd=d&st=0&ch=300&t=0&submit=Search
that may give you ideas.

There's more under xtracycle, and of course under the Surly versions, edgerunner, etc.

As mentioned with the 2WD/Dual controllers if I end up with just 2 batteries then it's either single battery per controller (simplest) or parallel to share the battery capacity to the two controllers, advantage is one controller can pull more watts over the total ride, the CA will be more accurate as it will be measuring the combined battery capacity remaining (not just one of the 2), etc.

I would use single-port (same for charge and discahrge) batteries, and I would have all batteries paralelled together, as well as the controller battery inputs. It's the simplest setup, as it lets you use just one shunt for the CA to monitor, and all batteries supply power at the same time to everything, and receive power at the same time during regen (making it easier on the BMS charge fets to accept the regen).

You can install breakers on the output of each battery, so you can isolate any of them if necessary.


Keep in mind the CA doesn't really measure battery capacity "remaining". It measures current passing thru the shunt, and counts that over time, to show Ah / Wh used up. As long as you know the actual capacity / charge state the batteries start a ride out at, that works fine. It also has a battery indicator icon that can be relatively useful, but isn't perfect, as it mostly works on voltage (but not completely).

All cable lengths as you can see now are normal length/short in length with the only long runs would be a) to the CA and b) from the front PhaseRunner to the Front motor.

The stuff ot the CA is not power-carrying, it's just data lines, so not important.

Thank you amberwolf!

I'm at the point now I just need to build and test and prototype my ideas carefully. You have been a great source of insight and experience. I look forward to sharing with you my final build decisions.

I did want to share, as it's quite new (only been available for a few months now) - Grin's CA3-WP Dual Controller Splitter:
https://www.ebikes.ca/shop/electric-bicycle-parts/wiring/ca3-wp-dual-controller-splitter.html

In May Justin did a great video talking about 2WD/Multi-Wheel drive setups and in the video he went into some detail of the design/operation of this new CA3-WP Dual Controller Splitter cable. I realize you have years of experience of 2WD builds but perhaps might want to skim through his video and for anyone else looking at 2WD builds it's a great primer I found.

https://www.youtube.com/watch?v=Ub4EP2_mAds

Anyways, hope you're doing well and thanks again for all your thoughts/feedback.

Shaun

 

[amberwolf]

I haven't watched the video yet (I prefer text articles with pics; I usually get more out of them, but Justin's stuff I'll watch. ), but the cable looks interesting for systems that use the controller shunts to read current.

I use a single standalone (SA) shunt out of the battery, to measure all current flow out of it into the whole system, instead. My throttle/PAS control setup isn't typical either (though at present it does all run thru the CA, eventually it won't because of certain things the CA does that I don't want my ssytem to do, and certain things the CA doesn't do that I do want my system to do).


FWIW, if you do end up using the system with that cable and the 0.5mohm Rshunt value, you have to swtich teh CA to high-range mode. Unless they've fixed it, there has been some odd behavior / bugs with that mode; I'd recommend looking thru the CA V3 beta thread starting at the most recent stuff and then going backwards thru time, to see what was reported and in what version, to see if it would affect you, and if it's been fixed or not (or even confirmed as a CA problem and not something elsewhere in a particular bike's setup).

I can't remember any of the specifics, but I had to switch back to low-range mode because of some of the issues, and use a single 1mohm Grin SA shunt (even though it's only rated 45A, IIRC, and my system draws at least twice taht for a few seconds on startup, and will be drawing even more than that on startup once I complete the Hi-Lebowski controller project).

 

[CdnShaun]

I haven't watched the video yet (I prefer text articles with pics; I usually get more out of them, but Justin's stuff I'll watch. ), but the cable looks interesting for systems that use the controller shunts to read current.

I use a single standalone (SA) shunt out of the battery, to measure all current flow out of it into the whole system, instead. My throttle/PAS control setup isn't typical either (though at present it does all run thru the CA, eventually it won't because of certain things the CA does that I don't want my ssytem to do, and certain things the CA doesn't do that I do want my system to do).


FWIW, if you do end up using the system with that cable and the 0.5mohm Rshunt value, you have to swtich teh CA to high-range mode. Unless they've fixed it, there has been some odd behavior / bugs with that mode; I'd recommend looking thru the CA V3 beta thread starting at the most recent stuff and then going backwards thru time, to see what was reported and in what version, to see if it would affect you, and if it's been fixed or not (or even confirmed as a CA problem and not something elsewhere in a particular bike's setup).

I can't remember any of the specifics, but I had to switch back to low-range mode because of some of the issues, and use a single 1mohm Grin SA shunt (even though it's only rated 45A, IIRC, and my system draws at least twice taht for a few seconds on startup, and will be drawing even more than that on startup once I complete the Hi-Lebowski controller project).

Thank you! I have the cable and is my plan to use it. I will take this insight and review the thread and what information I have available, perhaps call Grin to follow up as well. I will post back if I determine it's an issue that this cable may need to be considered or if it's no longer an issue.

Thank you!
Shaun