Questions: Track & Trail set-up. Charging & Transport.

[flailer]

Hey all,

I’m a Total Noob to electrics, but vet of gas, street riding, sumo-track, woods, & enduro.

I’m seriously considering getting a Varg, but will not until I figure out transportation & track support configurations. I’m leaning towards a cargo trailer w 800 to 1,500 watts of solar on top, 9 12V batteries, or 4 24V batteries , and an inverter of course.

In this config I could load any number of toys & tools, as well as put a small kitchenette & lounger inside. Seems like it would work both e-toys as well as gas for Dirt track, Sumo track, & deep woods. A huge plus is that it should make make cross country trips much more viable, which is also a LARGE consideration.

While I’m no longer into quads, surfing, or river-running, it should work well there too. It seems like this configuration would be a major overkill for my frequent mtn biking & overnighters, but I don’t mind as I wouldn’t take it if the benefits weren’t worth it. I have other uses for a trailer as well, and a cargo trailer is a fairly good option in that regard.

It seems like cost is the only negative. Something like $5k + cost of trailer.. So $10k plus or minus $1k. But I could carry all the tools, tires, bits, parts, pieces, riding gear, as well as swap out wheel-set! And that makes it priceless in my book.

Perhaps you guys can share what you are doing? And maybe someone here, anyone here, can pick on the weakest points or limitations of what I’ve spelled out?

Thanks.

F

 

[LTJ]

Maybe not exactly what you are looking for, but I bought an aluminum utility trailer and built a structure on it for a shower, stove, RTT, shade, and marine battery to power shower and lights. It's an open trailer as I still want to use it for dump runs. It was worked out very well for dirt bike camping (holds 3 dirt bikes) and I also added a hitch carrier to carry 3 mountain bikes. If I was to take the Varg up in the mountains, I would take my existing yamaha 2000W gas generator to charge up between rides, but probably would eventually get a larger generator. The trailer was used for $300, the metal was $1000.

 

[flailer]

Maybe not exactly what you are looking for, but I bought an aluminum utility trailer and built a structure on it for a shower, stove, RTT, shade, and marine battery to power shower and lights. It's an open trailer as I still want to use it for dump runs. It was worked out very well for dirt bike camping (holds 3 dirt bikes) and I also added a hitch carrier to carry 3 mountain bikes. If I was to take the Varg up in the mountains, I would take my existing yamaha 2000W gas generator to charge up between rides, but probably would eventually get a larger generator. The trailer was used for $300, the metal was $1000......

Oh wow man, that is a completely awesome configuration !!

See, that's exactly what I'm asking about!! and the info you provided about having a shower too is PERFECT. Great idea!

Right now I'm limited to either my truck or van, and neither are kitted half as well as I'd like.. Yours is a great role model.

You put the hitch-receiver for bicycle rack on the back? I didnt see it in the pics.

 

[LTJ]

Thanks! You can see on the shelf below the bbq and stove is another hitch mount I welded in place. I can fit a 3 rail mtb bike rack there. I haven't used that feature yet (at least not towing with my truck). I will need to run an extended hitch (sold on amazon) so the bike rack doesn't hit the camper shell on my truck when I make turns.

Also, I welded this whole thing together with a cheap Harbor Freight flux core welder ($129). It has since died (replaced with a sweet Hobart multi welder), but got my money's worth to build this thing. Also a good investment is a good chop saw to cut steel tubing. I used a grinding chop saw and it was okay, but since upgraded to a blade shop saw. Cuts like butter.

The shower works with a cheap amazon water pump hooked up to my marin battery. I also put in party led lights inside the structure to light things up nicely. I have yet to put on a RTT, as I'm deciding if I really need it, or make one, or buy one. I have a camper shell on my truck with a deck drawer system and foam mattress. My truck (raptor) has the shorter bed, but I can lay diagonally in the bed comfortably (I'm 6 ft).

 

[flailer]

Thanks! You can see on the shelf below the bbq and stove is another hitch mount I welded in place. I can fit a 3 rail mtb bike rack there. I haven't used that feature yet (at least not towing with my truck). I will need to run an extended hitch (sold on amazon) so the bike rack doesn't hit the camper shell on my truck when I make turns.

Also, I welded this whole thing together with a cheap Harbor Freight flux core welder ($129). It has since died (replaced with a sweet Hobart multi welder), but got my money's worth to build this thing. Also a good investment is a good chop saw to cut steel tubing. I used a grinding chop saw and it was okay, but since upgraded to a blade shop saw. Cuts like butter.

The shower works with a cheap amazon water pump hooked up to my marin battery. I also put in party led lights inside the structure to light things up nicely. I have yet to put on a RTT, as I'm deciding if I really need it, or make one, or buy one. I have a camper shell on my truck with a deck drawer system and foam mattress. My truck (raptor) has the shorter bed, but I can lay diagonally in the bed comfortably (I'm 6 ft).

Welp, I don't like sounding stupider than usual, but what's an RTT ? I thought it would come to me after your first post, but I still don't get it.

 

[LTJ]

Roof top tent

 

[flailer]

Roof top tent

thanks!
yeah, I'm looking to use the inside of the cargo trailer for overnighting.. but it's likely to be rarely used that way. Like you the truck , or van, should work quite well for that.

 

[Philip]

Cool thread! I have been towing a closed cargo trailer behind my camper van. I like it, it gives me more room in the van, but the whole train is longer and heavier. Plusses and minuses in everything, as expected.

9 12V batteries, or 4 24V batteries

How did you calculate this, and are they lead-acid or lithium batteries? I won't touch lead acid for anything mobile or deeply and frequently dischargeable.

 

[flailer]

Cool thread! I have been towing a closed cargo trailer behind my camper van. I like it, it gives me more room in the van, but the whole train is longer and heavier. Plusses and minuses in everything, as expected.


How did you calculate this, and are they lead-acid or lithium batteries? I won't touch lead acid for anything mobile or deeply and frequently dischargeable.

Hey MrDudeMan,

Welllll... please do take my numbers with a large grain of salt, I know I am. And I'll recalculate again when I get to the actual build stage.

If memory serves I calculated them "backwards" from the voltage inverter (that someone here recommended.) I looked at the draw of said inverter & realized that it would take 4.1 times the battery capacity of my last solar build ( for my tiny RV, a B+ , with minimal electrical draw, no microwave usage etc.)

If memory serves I left a healthy bit of elbow room on the battery side of things, but not on the solar panel side of things as I figured I'd be arriving at track with the bike and cargo trailer's (edit) batteries already fully charged.

The panels, even at 1,500w would be a slow charge of the cargo trailer's batteries. shrugs. I really don't think there is enough roof-top space on a cargo trailer to build a fast charge system, so I didnt even look in that direction. So, I focused on battery capacity, and less so on solar capacity. Heck you have the space in the cargo trailer, you could store panels inside & lay 'em out the ground if you think it wise .. BUT it prolly not, at the track anyway.

There are plenty of online calculators for crunching these numbers. We have to take losses on the part of the invert (~10%) into account as well. Huh.

Considering where you are located, I'd think that there are TONS of people doing solar. Professional installers to rank amateurs like me. Heck, the sales people I dealt with, for Solar panels, charges, batteries, cabling, fuses, Switches, & connectors (every bit I needed to get the job done) were very helpful, and didn't try to over-sell me.

Your mileage may vary.

 

[Philip]

Stark Varg has a ~7 kWh battery. It would be very good to have ~7 kWh of lithium batteries in your trailer so that you could bring a fully charged bike to the track, drain the battery, and then charge it one more time. That would be a very good and long day of riding. Of course, it all depends on your battery-draining skills. Also, if you have a large solar array like the one that you are dreaming about, then you will be adding about 2 - 7 kWh of charge from solar in a day, which would help you ride much longer, and may even let you get away with a smaller battery array.

Or you could just buy a portable gas generator for $1K and not worry about lithium and solar. But that is noisy, smelly, and not as cool. But very cheap in comparison to other options. And you will quickly learn how much charge you will actually need for your average track day. And then you can sell that generator once you find better alternatives and get most of your money back.

Or you could install an under-hood second alternator on your truck and use that as a generator and/or to top off your batteries. Lots of options.

In any case, make sure your inverter or generator has a 240V output. That will be a lot less waiting for your bike to charge. You may not even have to wait at all because you will need to rest sometimes, and once you are rested the bike will be ready to ride again.

 

[flailer]

Stark Varg has a ~7 kWh battery. It would be very good to have ~7 kWh of lithium batteries in your trailer so that you could bring a fully charged bike to the track, drain the battery, and then charge it one more time. That would be a very good and long day of riding. Of course, it all depends on your battery-draining skills. Also, if you have a large solar array like the one that you are dreaming about, then you will be adding about 2 - 7 kWh of charge from solar in a day, which would help you ride much longer, and may even let you get away with a smaller battery array. Or you could just buy a portable gas generator for $1K and not worry about lithium and solar. But that is noisy, smelly, and not as cool. But very cheap in comparison to other options. And you will quickly learn how much charge you will actually need for your average track day. And then you can sell that generator once you find better alternatives and get most of your money back. Or you could install an under-hood second alternator on your truck and use that as a generator and/or to top off your batteries. Lots of options. In any case, make sure your inverter or generator has a 240V output. That will be a lot less waiting for your bike to charge. You may not even have to wait at all because you will need to rest sometimes, and once you are rested the bike will be ready to ride again.

Standing Ovation

Plus, under your system I could switch the charging system from the cargo trailer, to the van, or RV, or even the truck in just a couple of minutes. Try that with solar panels!! .. Going to the local sumo track: use the truck. Going to the woods: use the van. Going cross country use the RV towing the cargo trailer. Yep.

Cheaper, faster & stronger. In short solar is a luxury. I know that, and people who aren’t willing to admit it are (typically) useful “idgets” for political causes. smFh.

Still thinking out loud: I’d still want a back-up battery bank. If the Varg had swap-able battery, I’d just get a second MC battery. And that would be, BY FAR, the best.. That way I wouldn’t have to listen to the generator charging the 2nd Varg battery, as I would be on the track or trail while it is charging.

For anyone considering any of these options remember that the inverter is going to waste approximately 10%. If we don’t account for that we’d never.. not even once, never ever get a full charge.

But who am I?

p.s. I have both solar & generator built into my RV. The RV came equipped w the generator, but still I added solar.. not because it’s “green” -solar isn’t green by the way- but I added it for personal preferences. I like coming back into camp with everything already to go, fully charged, ready to relax, and not listen to a freak’n azz-h0e generator

p.p.s. I’d rather not run my truck or van or RV engine to charge anything up.. except while running down the road to my destination.

 

[AgileMike]

I would start with a gas generator. You need at least 3.3kw continuous power at 220v to fast charge. This is the best buy, IMHO, that meets the Starks fast charge needs:

https://www.costco.com/a-ipower-gxs7100ird-7100w-dual-fuel-inverter-generator.product.4000078099.html

If you want to go solar, I have a 20' cargo trailer. I've purchased all the solar stuff but haven't installed in yet (injured ankles in a moto crash). You can build a massive solar system for under 5k. I'm also going to use the solar on the trailer to charge our Teslas when we the trailer is parked at home.

Panels:
400W+ residential panels work well.
signaturesolar.com/aionrise-395w-mono-crystalline-perc-solar-panel-black-aion72g1

All in One Inverter:
This will accept input from solar, generator, battery bank and shore power. Makes wiring much, much easier.

EG4 6000XP Off-Grid Inverter | 8000W PV Input | 6000W Output | 480V VOC Input | 48V 120/240V Split Phase | All-In-One Solar Inverter

EG4 6000XP Off-Grid Inverter: 6000W output, 8000W PV input, 480V VOC, and 48V split-phase 120/240V. Efficient power for off-grid setups.

signaturesolar.com

Battery Bank:
Big boy (2x Stark battery):

EG4-WallMount Indoor Battery | 48V 280Ah | 14.3kWh | Indoor | Heated UL1973, UL9540A | 10-Year Warranty

EG4 Wall Mount Indoor Battery: 48V 280Ah, 14.3kWh capacity, heated, UL1973 & UL9540A certified, with a 10-year warranty for reliable energy storage.

signaturesolar.com

Small size (need two of them to fully charge Stark)

EG4-LifePower4 V2 Lithium Battery | 48V 100AH | Server Rack Battery | UL1973, UL9540A | 10-Year Warranty

The EG4 LifePower4 V2 Lithium Battery 48V 100AH provides reliable energy storage for server racks, ensuring uninterrupted power supply with its efficient and high-capacity lithium technology.

signaturesolar.com

The All in One Inverter and compatible batteries make this system very easy to wire up. Tons of videos on YT explaining how to do it.

https://www.youtube.com/@WillProwse

 

[flailer]

I would start with a gas generator. You need at least 3.3kw continuous power at 220v to fast charge. This is the best buy, IMHO, that meets the Starks fast charge needs:

https://www.costco.com/a-ipower-gxs7100ird-7100w-dual-fuel-inverter-generator.product.4000078099.html

If you want to go solar, I have a 20' cargo trailer. I've purchased all the solar stuff but haven't installed in yet (injured ankles in a moto crash). You can build a massive solar system for under 5k. I'm also going to use the solar on the trailer to charge our Teslas when we the trailer is parked at home.

Panels:
400W+ residential panels work well.
signaturesolar.com/aionrise-395w-mono-crystalline-perc-solar-panel-black-aion72g1

All in One Inverter:
This will accept input from solar, generator, battery bank and shore power. Makes wiring much, much easier.
signaturesolar.com/eg4-6000xp-off-grid-inverter-split-phase

Battery Bank:
Big boy (2x Stark battery):
signaturesolar.com

Small size (need two of them to fully charge Stark)
signaturesolar.com/eg4-lifepower4-v2-lithium-battery-48v-100ah-server-rack-battery-ul1973-ul9540a-10-year-warranty

The All in One Inverter and compatible batteries make this system very easy to wire up. Tons of videos on YT explaining how to do it.

https://www.youtube.com/@WillProwse

.. Excellent!

Question: Why use bifacial panels when mounting on the cargo trailer roof? Is there any benefit? Aren’t they meant, ideally, for vertical mounting? or at least 4ft off the ground? I dunno.

I was really hoping someone would tell me I’m wrong about the Stark not having swap-able battery pack.

 

[Theo]

I was really hoping someone would tell me I’m wrong about the Stark not having swap-able battery pack.

Officially, the battery is not swappable: that's what A. Wass said in an interview.
However, technically it can be done; the procedure to change a battery is shown in the specific video in the Stark's YouTube channel and, like mentioned in this post, someone does swap batteries.
I see some problems here, though:
• maybe swapping batteries that way could be considered as maintenance not authorised by Stark that will void the warranty.
• The only way I know to charge a battery is to connect it to a Varg, so if you wanted to bring an extra battery with you, you should first charge the one already in the bike, then swap the battery or maybe just keep the other one as close as possible to the bike if the cables are long enough, and then connect it to the Varg and recharge it.
• The sockets of the batteries and the plugs they mate to are probably not designed to be disconnected and reconnected on a weekly basis and so maybe in the long run they could fail if used like that.
• It looks like changing that heavy battery, especially when it's dirty and you are trying to preserve energy -I mean your human energy- to ride, can be tiring and stressful.

 

[flailer]

Officially, the battery is not swappable: that's what A. Wass said in an interview.
However, technically it can be done; the procedure to change a battery is shown in the specific video in the Stark's YouTube channel and, like mentioned in this post, someone does swap batteries.
I see some problems here, though:
• maybe swapping batteries that way could be considered as maintenance not authorised by Stark that will void the warranty.
• The only way I know to charge a battery is to connect it to a Varg, so if you wanted to bring an extra battery with you, you should first charge the one already in the bike, then swap the battery or maybe just keep the other one as close as possible to the bike if the cables are long enough, and then connect it to the Varg and recharge it.
• The sockets of the batteries and the plugs they mate to are probably not designed to be disconnected and reconnected on a weekly basis and so maybe in the long run they could fail if used like that.
• It looks like changing that heavy battery, especially when it's dirty and you are trying to preserve energy -I mean your human energy- to ride, can be tiring and stressful.

Thank you!

Not having swap-able batteries stopped me from buying an e-mtn bike in the past.

As an R&D engineer myself (retired) I understand the importance, restrictions, & liabilities of design features.. BUT, swapping batteries does a total end-run around the greatest limitation of the Stark. (No, price isn’t the greatest limitation, lack of battery-performance, distance, is the largest.)

I’m now at the point where I think that I will not buy a Stark. At least not until they address this pivotal PROBLEM.

 

[Chadx]

I would start with a gas generator. You need at least 3.3kw continuous power at 220v to fast charge. This is the best buy, IMHO, that meets the Starks fast charge needs:

https://www.costco.com/a-ipower-gxs7100ird-7100w-dual-fuel-inverter-generator.product.4000078099.html

If you want to go solar, I have a 20' cargo trailer. I've purchased all the solar stuff but haven't installed in yet (injured ankles in a moto crash). You can build a massive solar system for under 5k. I'm also going to use the solar on the trailer to charge our Teslas when we the trailer is parked at home.

Panels:
400W+ residential panels work well.
signaturesolar.com/aionrise-395w-mono-crystalline-perc-solar-panel-black-aion72g1

All in One Inverter:
This will accept input from solar, generator, battery bank and shore power. Makes wiring much, much easier.
signaturesolar.com/eg4-6000xp-off-grid-inverter-split-phase

Battery Bank:
Big boy (2x Stark battery):
signaturesolar.com/eg4-wallmount-indoor-battery-48v-280ah-14-3kwh-indoor-heated-ul1973-ul9540a-10-year-warranty

Small size (need two of them to fully charge Stark)
signaturesolar.com/eg4-lifepower4-v2-lithium-battery-48v-100ah-server-rack-battery-ul1973-ul9540a-10-year-warranty

The All in One Inverter and compatible batteries make this system very easy to wire up. Tons of videos on YT explaining how to do it.

https://www.youtube.com/@WillProwse

Was reading down the thread and ready to type nearly this identical post. Now I don't have to. Ha.

@flailer
Definitely go with 48v batteries. And the all-in-one inverter. It's a shame the smaller EG4 3kW (EG4 3kW Off-Grid Inverter | 3000EHV-48 | 3000W Output | 5000W PV Input | 500 VOC Input) doesn't do 240v like the EG4 6000XP @AgileMike linked to.

Solar collection is quite variable. Angle of the sun to panel face is one of the largest (seasonal, time of day, orientation of panels, etc.) Being able to tilt the panels towards the sun is huge, though you have to be there to adjust. Mid-summer, laying flat is fine, but in spring or fall, being able to angle the panels to the south or better yet to the east, then south, then west as the son moves really adds to how much power you will collect. Then the other stuff like keeping panels clean, haze/clouds/shade, and the panels getting hot (important to have a nice air gap underneath them) all play a part.

On perfect summer conditions, figure about 5x collection per day of your panel size. So a 1,000watt array would collect about 5kWh give or take (including solar controller loses). 1,500watts would generate closer to 7,500watts in a day, which is about the minimum you'd want. Now, change that from a sunny July day to a overcast day or a early spring or late fall day and your daily generated watt hours can drop to 1/2 - 1/4 that in a hurry. Definitely not as reliable as a generator, but much more interesting and fun. You just have to live with the variables. And, if your batteries are 100% SOC before you leave, that is at least one full recharge before you go. Really depends on if you are needing a fully charge every day or there will be days in between chargings.

And, you could do all this and still have a small generator for the days when solar is not regening your battery bank. It can be a 120v and just sit there and push current into your all-in-one when you need it to even while you are out riding. Just don't do that in a campground or anywhere else you'll annoy other folks camping. Dispersed it doesn't matter. Just make sure no flamables are nearby (dry grass, etc.) since you won't be there tending it.

You'll also have loses from converting from your 48v DC battery to 240v AC outlet, then again, with the Varg charger, that is an inverter charger going from AC to the Varg's DC current to charge the Varg's battery. Ideally, one would buy/build your own DC/DC converter to go directly from 48v DC battery bank to the appropriate DC voltage to charge the Varg battery. That would be way less lossy since you are staying DC and only converting voltage.

 

[Chadx]

Thank you!

Not having swap-able batteries stopped me from buying an e-mtn bike in the past.

As an R&D engineer myself (retired) I understand the importance, restrictions, & liabilities of design features.. BUT, swapping batteries does a total end-run around the greatest limitation of the Stark. (No, price isn’t the greatest limitation, lack of battery-performance, distance, is the largest.)

I’m now at the point where I think that I will not buy a Stark. At least not until they address this pivotal PROBLEM.

If it helps, Varg are currently on sale for $2,000 off MSRP, so that can help fund your solar trailer or generator projects.

 

[flailer]

If it helps, Varg are currently on sale for $2,000 off MSRP, so that can help fund your solar trailer or generator projects.

“Yeah, no” .. as stated, price isn’t the Varg’s issue. Battery capacity is the largest PROBLEM.

Design changes so batteries can be swapped is the most obvious & easiest solution. Is is not?

 

[fsfs]

“Yeah, no” .. as stated, price isn’t the Varg’s issue. Battery capacity is the largest PROBLEM.

Design changes so batteries can be swapped is the most obvious & easiest solution. Is is not?

Making the battery easily swappable would make the bike a bit heavier. Other people would gladly trade battery capacity for lower weight, but for you battery capacity is the largest problem. Basically, you have to make some design choices -- those choices are desirable for some people but not so much for other people.

From a purely mechanical point of view swapping batteries isn't so much trouble. However, having to remove the plastics, fender, and carbon subframe to get at the bolts and connectors adds to the time required to do the job. Perhaps the plastics could be modded to eliminate the need to remove them.

From an electrical point of view I suspect one big issue is the number of mating cycles on the orange power connector. The electronics required to charge the battery outside the bike would be pretty easy to do -- it would basically be a simplified VCU with an integrated charging connector... Might even be a good product idea for the Varg.

 

[Chadx]

“Yeah, no” .. as stated, price isn’t the Varg’s issue. Battery capacity is the largest PROBLEM.

Design changes so batteries can be swapped is the most obvious & easiest solution. Is is not?

Battery can be swapped. Just not quickly/easily. That was a design choice to help meet weight and packaging needs (and even with that they struggled with keeping weight down to target weight).

It's similar to packaging of portable devices like mobile phones, like others have mentioned; having built-in batteries allows for more compact dimensions, lower weight, etc. Stark had an early video on the reasons behind it.

It would be nice to have a quickly swappable battery but that would introduce a lot of design compromises for little benefit to their core audience, which are track riders; not trail riders.

Will be interesting to see when/if they come out with a trail/enduro bike and how it's designed. My preference would be if it had a swappable battery and they offered different capacities. Like one over 7kWh for those that need the range and are willing to live with the extra weight. but also offer a smaller 3kWh or 4kWh options for those that don't want/need the range or can stop and swap battery when they need to.