3WD hybrid GO-4 project

[Lia Raven Gerty]

Basic premise: Slap a hub motor on to the front a Westward Industries GO-4 Interceptor.

My experience: Back in 2011 I built an e-bike out of a tandem with a 9C kit from ebikes.ca and four lead-acid batteries. I've also done a lot of mechanical, fibreglass, and brazing work on motorcycles; and building the e-bike taught me enough electrical background to set up all the electrics of my off-grid cabin.

Goals: Cruise on electric power only up to 10 MPH to avoid waking up the neighbours, get more traction on muddy roads, prolong the life of the trike's obscure gas motor, and reduce fuel consumption by taking advantage of regenerative braking, solar power at home, and EV charging at school.

Why not a bike?: I'm sick and tired of being attacked by dogs everywhere I go. Recently I gained some new neighbours with some nasty dogs and they're making my life hell and I live waaaay out in the jungle where you can't count on law enforcement to help you. Also, my uncle's now too old to drive me around when I need to move things I can't carry on my Ruckus. Finally, I can convert the GO-4 into a van and sleep in the back if I have to!

Why a GO-4: It seems to be the cheapest thing I can get with less than 4 wheels and an enclosed cab. Also, the sliding doors, automatic transmission, and 70 MPH top speed are huge points over the much more expensive Piaggio Ape. Cushmans aren't made anymore which is concerning for parts availability. I've found and agreed to buy a GO-4 from a guy in California, just waiting for funds to clear before I get it shipped out here.

Budget: $4k for the motor, batteries, controller, etc.

Mechanical considerations: The stock front tyre is a 155/80-13. It doesn't look like I can go much bigger without new fork tubes, which would add $$$ no doubt. The vehicle has a GVWR of 2000 pounds, but only 675 of that is on the front axle.

Where I'm at:
AFAIK my options for a motorcycle-class hub motor are QSmotor, Golden Motor, and Enertrac. Golden Motors are either too large or too slow. QS motors look like they'll do the job, but I'm concerned about axle strength. Enertracs are too big as-is, but maybe I can work with them to get one made with a 13" rim? As for battery, since this is a hybrid I'm much less concerned about range than I am about safe charging and enough capacity to absorb regen currents. Finally, I really loved the Cycle Analyst my old e-bike had, and would love to incorporate one of those if it'll work with a big enough controller.

 

[amberwolf]

QS motors look like they'll do the job, but I'm concerned about axle strength.

They make car-capable motors, so they should be able to make axles that are good enough--but you'd have to speak to them directly about your requirements. ATM it's one of the big Chinese holidays, so it'll be a little while before you get a response, most likely.

Finally, I really loved the Cycle Analyst my old e-bike had, and would love to incorporate one of those if it'll work with a big enough controller.

You can use a CA on anything electric as long as it's DC. You just have to either use a separate shunt wired into the battery-to-controller negative cable, or add a "CA connector" to whatever controller you get. How to wire that in is on the ebikes.ca site and several threads here on ES, though you have to determine the exact wiring points inside the controller yourself.

http://ebikes.ca carries the CA-SA-HC / HV versions that have an external shunt that will probably do what you want.

 

[Lia Raven Gerty]

They make car-capable motors, so they should be able to make axles that are good enough--but you'd have to speak to them directly about your requirements. ATM it's one of the big Chinese holidays, so it'll be a little while before you get a response, most likely.

Right, I see that they do. It's just that all the dual-sided-axle motors they have seem to have the same tiny threaded axle, so if that's not strong enough they'd have to do something custom, if they even would.

I'm aware of the holiday and in no rush It'll probably be a few weeks before I even get the trike in front of me to take measurements!

though you have to determine the exact wiring points inside the controller yourself.

Ah, I was afraid of that... but not deterred! I'm sure I can figure it out.

Just brainstorming a cart to put before the horse... I've been planning on having two throttles - gas on the right, electric on the left. But, it would be nice to have the gas throttle actually be a sort of smart throttle... and if the gas motor has a TPS, maybe I can pirate its signal into the electric circuit.

Say I have a 8000 W hub motor on the front, that's theoretically 1/5th as powerful as the 55 HP gas motor driving the rear. And I don't want to be running the electric if the batteries are low. So, where Te is the electric throttle, and Tg is the gas throttle position, and B is the battery level, I'd want to design a circuit to output like:

Te = Tg * 6.25 * ( B - 0.2 )

So, at 20% gas throttle, and 100% charge, I'd get 100% electric throttle. The amount of electric assist would decrease to 0 as the battery approaches 20% charge, and further reduced when the throttle is below 20%. Then, I could focus less on managing power and focus more on the road.

I hope y'all don't mind me posting about this hybrid stuff. I'd love to go all-electric, but, living off-grid and commuting over 100 miles a day through the mountains with a 1-ton vehicle would probably require a lot more battery than my $4k budget can realise. It's because of the mountains, however, and the constant acceleration and deceleration around hairpins, that I think some electric regen would be a nice thing to have. My bikes eat brake pads like crazy.

 

[amberwolf]

Ah, I was afraid of that... but not deterred! I'm sure I can figure it out.

Most of the info you need is in the various posts / threads about adding a CA connector to a controller.
This title-only search finds a few of the threads, but there's more than just these
https://endless-sphere.com/forums/search.php?keywords=add*+conn*+control*&terms=all&author=&sc=1&sf=titleonly&sr=topics&sk=t&sd=d&st=0&ch=300&t=0&submit=Search

. I've been planning on having two throttles - gas on the right, electric on the left. But, it would be nice to have the gas throttle actually be a sort of smart throttle... and if the gas motor has a TPS, maybe I can pirate its signal into the electric circuit.

There are also cable-operated electronic throttles, so if you can either make a cable splitter or put a second cable on the throttle (so it has two parallel cables wrapping around the reel), you can use the same grip to control either one. Later tonight I'll have a post in my SB Cruiser thread about the ones I just got, with some pics, and links. There are a number of variations available around the web.

Say I have a 8000 W hub motor on the front, that's theoretically 1/5th as powerful as the 55 HP gas motor driving the rear. So, where Te is the electric throttle, and Tg is the gas throttle position, and B is the battery level, I'd want to design a circuit to output like:

Te = Tg * 6.25 * ( B - 0.2 )

So, at 20% gas throttle, and 100% charge, I'd get 100% electric throttle. The amount of electric assist would decrease to 0 as the battery approaches 20% charge, and further reduced when the throttle is below 20%.

A hardware circuit could do that, using op-amps or transistors to scale things, but if you know any coding it would be far easier to do with an arduino or other small MCU board. I don't know enough MCU stuff to help with that, but there are others here that do.

And I don't want to be running the electric if the batteries are low.

If the battery has a BMS, just ensure it's LVC is where you want to stop discharge at, and the electric system will always just shut off. The BMS does not have to handle the current flow, just have HVC, LVC, and cell-balancing; you can have the BMS cutoff signals operate a relay / contactor to actually carry the system current. (makes the BMS a lot cheaper, though it adds the cost of the contactor, like Gigavac, etc).

I hope y'all don't mind me posting about this hybrid stuff.

Ther'es a number of hybrid projects on ES, of various types.

It's because of the mountains, however, and the constant acceleration and deceleration around hairpins, that I think some electric regen would be a nice thing to have.

Just keep in mind that to get regen to work without damaging the battery, the battery has to be less than full, by at least whatever amount the regen is likely to put back into it. Otherwise, unless you have a BMS with HVC to shutoff input current, the batteyr can be overcharged. Usually that's only a worry if you are braking downhill right after leaving in your fully-charged state, but if ther'es a lot of regen braking and not much discharge it can still happen.

The problem with having the BMS HVC shut off charging the battery while doing regen is that while it protects the battery, it puts *you* in harm's way, because suddenly the braking doesn't work anymore, and if you were depending on it at that moment to not go over the cliff, well....

It's also possible (though unlikely) for the controller's output voltage to increase beyond what the FETs in it can take, if the battery shuts off input, becuase with no load (battery) on it it could spike pretty high voltage before the controller's protections engage and it shuts itself down.

So I highly recommend using the same brake lever(s) for regen as you do your mehcanicals, so all you ahve to do is squeeze harder to get the mechanical braking going (an instinctual move) rather than remembering to grab a different lever (delayed action, etc).

 

[Lia Raven Gerty]

There are also cable-operated electronic throttles...

A hardware circuit could do that, using op-amps or transistors to scale things, but if you know any coding it would be far easier to do with an arduino or other small MCU board.

I do know more about programming than I do about electronics, but I'll have to do some more research into either. In the meantime, the cable-actuated electronic throttle combined with a generous LVC sounds like it'd be a quick way to have the right throttle working both. I was thinking two throttles so I could run electric-only on occasion, but I suppose I could get by with just the one if I kill the engine when I don't need it... provided that opening the throttle while not running won't do any harm.

Just keep in mind that to get regen to work without damaging the battery, the battery has to be less than full, by at least whatever amount the regen is likely to put back into it...

The problem with having the BMS HVC shut off charging the battery while doing regen is that while it protects the battery, it puts *you* in harm's way, because suddenly the braking doesn't work anymore, and if you were depending on it at that moment to not go over the cliff, well.... ...

So I highly recommend using the same brake lever(s) for regen as you do your mehcanicals, so all you ahve to do is squeeze harder to get the mechanical braking going (an instinctual move) rather than remembering to grab a different lever (delayed action, etc).

Yeah, this is part of why I'm keen on the "smart" throttle idea, I want to make sure I'm using the battery so it'll have room for regen!

I came across a post somewhere about setting up a shunt to a dump load if the regen is too much for the battery, kind of like how you do with a wind turbine. Have it keep my tea warm while I'm on my way to class

My e-bike did have full on 12v lighting, and what I did there was wire the regen control in parallel to the brake light, so the regen would always activate first before the mechanical brakes would engage. I figured I'd do the same here.

 

[fechter]

Any idea how much a GO4 weighs? They look pretty heavy. It's going to take a really big electric motor to make that thing move.
If you get it dialed in right, you should be able to go full power on both gas and electric to get some impressive acceleration. Controlling the regen may be a bit challenging since many controllers don't behave well when the pack is full. Ideally you'd want the regen to back off gradually as the pack voltage approaches full. You also probably want a battery that can do a very high rate charge/discharge so the pack size can be reasonable.

 

[Lia Raven Gerty]

Yes, empty about 1500 pounds! I figure I'd want at least 3 kW to cruise through the neighbourhood at 10 MPH. With one of the big 8000W QS motors maybe I could even cruise through town at 20 MPH - and yes people actually drive that slow here.

Hm, yes sourcing an ideal controller might be interesting. Most of the time I see controllers advertised as an afterthought rather than a key component. It might be overkill, but I'd be tempted to get an actual wind/hydro charge controller to handle the regen- some of which can double as a smart mains battery charger - but most of those are designed for 12 - 48 V lead-acid batteries. I think I'd need to be running 60 or 72 volts so the motor won't be a drag when the gas is pushing 65 MPH, and the only wind/hydro controller I know of that can deal with 72V batteries is like $650. But, charging safety is a priority, and if a $650 battery charger means it won't explode when left charging unattended... well, I've never had a battery fire, but I have had a lead-acid battery burst and that was scary enough.

 

[Lia Raven Gerty]

1 month update, I've paid for the GO-4 and have title in hand, just waiting for it to make it across the ocean. Looks like it'll be another month before I finally get my hands on it to take measurements on the forks. But, since batteries will likely be the most expensive component and January will be the only time where I'll be able to spend more than 1.5k on any one item, I've been researching my options in advance.

My prior experience with e-bikes has only been with NiMH and SLA. The vehicle is heavy enough without throwing SLA batteries in there, so I'm hoping for nickel or LiFePO4, as it sounds like LiFePO4 is the safest and most economical of the lithium chemistries.

I found a link on here to EM3ev, where there's a large 72V ~25-29 AH battery for sale at only 1.1k. However, it says the BMS limits charge current to 12 amps? That sounds low for regen, although it also sounds safe...

BMS battery seems to have the next largest contender with a 72V 15 AH battery with no specified charge current limit. Despite the lower capacity, it weighs in 6kg more than the EM3ev battery. I've heard mixed reviews of BMS battery.

Then there's used hybrid car batteries. Used makes me nervous, and it seems the voltages are very high - 100-300V. I wonder whether a QS motor will handle 100V. Most seem to be NiMH or Li-ion, haven't heard of a common EV that uses LiFePO4. Honda hybrids seem to have the smallest and lowest voltage batteries, e.g. the Civic and Accord hybrids with their 100V 8Ah batteries.

And then there's Westward Industries itself, which produces an all-electric version of the GO-4 with a 96V, 20kwh LiFePO4 battery. I imagine that battery is probably huge and expensive if I could get them to sell one to me, and yet even with that the electric GO-4 doesn't have enough range for my needs. Hybrid is the way to go in my situation it seems.

 

[fechter]

I would be looking at used EV or hybrid car batteries. Most of them are easily dismantled and can be configured for a lower voltage.
Nissan Leaf or Chevy Volt batteries are the most plentiful.

 

[Lia Raven Gerty]

Hey, thanks! I never would have thought of dividing a large battery pack, usually I'm trying to do the opposite! And a factory EV battery is probably composed of matched cells, so maybe I could parallel the divided strings, assuming they're not already and there's not too many bad cells. The rule-of-thumb I picked up working on solar installations was not to do more than 3 parallel strings, although that's working with imperfectly matched flooded lead acid batteries.

 

[fechter]

With lithium batteries you can parallel as many as you want, but do it at the cell level, not strings.

 

[Lia Raven Gerty]

It took a while for my trike to make it across the ocean, and it's taking another while to get it into road-worthy shape, but it's almost there.

The forks on this thing are massive. 51mm tubes, and a 32mm axle! QSMotor axles are "only" 18mm, and I briefly considered mounting the motor with some 7mm thick rubber spacers. However, the forks are also not in the best of shape - they stick - and do not give me decent enough ground clearance, so I'm contemplating a swap.

The thing is, what could possibly donate fork legs to fit 51mm clamps? I'm tempted to put some USD forks from like a YZF-R1 in there, as they are easily found and would sort of fit with a little hacking, but going USD would mean stepping down in fork tube diameter. Whatever I use will probably require some custom springs!

 

[fechter]

Post a picture of the fork.

 

[tigcross]

I've had really good luck ordering batteries direct from Unit Pack Power in China. The batteries I've had them make for me were 72 V 20AH, I've gotten 3 and they've all been great. Cost per battery before shipping was $498 USD

http://www.unitpackpower.com/

 

[amberwolf]

The thing is, what could possibly donate fork legs to fit 51mm clamps?

motorcycle forks of various kinds would likely fit, from big touring or cruising bikes.

wrap the legs with "coiled up" sheet metal to fill the extra space.

or cut tubing in half of a diameter greater than the legs and smaller than the clamps, and use those as spacers, layer as needed.


as for the size of the forks / going "down" in diameter, if you get higher quality forks of better design and metal composition, they may well be stronger than the bigger ones.

also, you can replace the clamps and steerer, too, if the headset of the replacment fits the steering tube of the frame.

 

[amberwolf]

I've had really good luck ordering batteries direct from Unit Pack Power in China.

keep in mind that according to docw009 here
https://endless-sphere.com/forums/viewtopic.php?f=3&t=104459&p=1527687
a lot of their packs do not have a balance function in their bms, so if the cells begin to unbalance for whatever reason, the bms can't fix it, and since it has no way to tell you that there is a problem, the packs with this type of bms will just get less and less range / capacity as the cells get more and more out of balance. (and potentially other issues like being unable to supply as much "oomph" once the low cells get low enough relative to the high cells).

(if the cells are well-matched, and of high-quality, and not run down to dead empty much, then it's unlikely to be a problem...but in my experience reading about "generic" prebuilt packs in general, and how people tend to use them, none of those is likely to be true, so problems may be more likely over time with a pack that has a bms with no balancing function).

i don't know anything about the company directly, just what people post here, so you'd have to look this up to see what percentage of their packs are made this way, etc.

 

[tigcross]

a lot of their packs do not have a balance function in their bms,

Hmm, Interesting info. I'll have to keep an eye on my packs. The oldest is over 5 years old and still going strong, but I never run them all the way down and usually only charge to 85%

 

[CONSIDERABLE SHOUTING]

Going back to the throttle and electric mode issue- what does this have for an engine, and how is the throttle body operated? If it's like most current car engines and is an electronic throttle with potentiometer, you could piggyback off the signal wire to the throttle. I would also consider some of the hand controls used for the disabled as a way of controlling the front motor. My real concern is however, that you won't use the electric motor enough to really make the cost worthwhile.

Since you mentioned the Piaggio Ape... are you in Italy?

 

[Lia Raven Gerty]

Post a picture of the fork.

I'll try to get a shot of the uppers tomorrow or Monday - it's up in a friend's garage a few miles from home atm - but here's the lowers. Somewhat strange how they adapted a motorcycle fork to mate up with a car wheel, but I guess that's to make it easy to carry a spare that can swap to any of the three wheels.

The thing is, what could possibly donate fork legs to fit 51mm clamps?

motorcycle forks of various kinds would likely fit, from big touring or cruising bikes.

wrap the legs with "coiled up" sheet metal to fill the extra space.

or cut tubing in half of a diameter greater than the legs and smaller than the clamps, and use those as spacers, layer as needed.

as for the size of the forks / going "down" in diameter, if you get higher quality forks of better design and metal composition, they may well be stronger than the bigger ones.

also, you can replace the clamps and steerer, too, if the headset of the replacment fits the steering tube of the frame.

It seems that the vast majority of bikes top out at 49mm... which mightn't be too bad, I'd only need a 1mm thick shim. Hopefully the lip at the top is more than 1mm. There's like, zero clearance between the top of the shocks and the dash, so whatever I swap needs to have a flat top.

It looks like the steerer is removable, but I haven't been brave enough to try and remove it yet given my friend is hosting it atm.

Going back to the throttle and electric mode issue- what does this have for an engine, and how is the throttle body operated? If it's like most current car engines and is an electronic throttle with potentiometer, you could piggyback off the signal wire to the throttle. I would also consider some of the hand controls used for the disabled as a way of controlling the front motor. My real concern is however, that you won't use the electric motor enough to really make the cost worthwhile.

Since you mentioned the Piaggio Ape... are you in Italy?

It's got a 4-cylinder city car engine. I haven't looked at the throttle yet, but it does have a governor of some sort.

The sort of driving I do around here, there's loads of potential for regenerative braking - and closer to home, having all wheels driven is a big plus. And then there's the consideration that the little Hyundai engine it's got has not been used on any real car ever imported into the US, so replacement parts and mechanics who know how to work on it are going to be rare and nonexisitent, respectively. So part of the idea is to prolong the life of the gas engine. Another thing is that I live waaaay out in the middle of nowhere, and having a backup engine could make the difference between having it limp home and having it set on fire by vandals who prowl around looking for disabled vehicles to light up.

Far from Italy, I'm in Hawai'i. I just mentioned the Ape as something that is remotely obtainable...

 

[SlowCo]

That is an ideal front fork to place a hub motor in/on. You can replace the lower clamp with (a steel) one that fits the flats of a hub motor axle to clamp the axle in place.