Emergency fuel can for frunk

[jadnashuanh]

On many fuel cans, the cap is much more than simply a seal. SOme have an overpressure valve and some may also have a valve that can let air in to prevent it from collapsing say when part full and the temperature drops radically. Both of those functions are relying on vapor pressure, and laying the thing on its side would either prevent them from working or spewing liquid fuel. Not a good situation.

 

[Vach]

I'm not planning on driving around with it full 100% of the time either, and the Rotopax is pretty awesome, but as many have said it is pretty pointless in this area. It's just nice to have a backup.

That said, I personally feel it doesn't matter where it is stored in the car — the risk is the same. In fact, the motor and Rex are in the rear, so storing it back there probably increases the risk depending on the accident.

After two motorcycle accidents, I'm not worried, but I appreciate the analysis.

 

[electrons]

Wondered about this myself. With a 5-gallon jerry can (like they strap to the back of jeeps and Land Rovers), you could get 210 miles without stopping at a gas (petrol) station. You would pull over every 55 miles and top off your on-board tank.
Another person posted the following, & it would work for a large jerry can strapped to it securely:

This may be of interest. I believe you can attach various carriers
http://torkliftcentral.com/rving-and-towing/ecohitch/bmw/2014-bmw-i3-ecohitch-reg
There is also a YouTube video showing how to install

Really useful of course for bikes. Jerry can would free you up to make long trips when you had to.

 

[TOEd]

We have had our i3 REx for exactly two months. In that time we have driven 2890 km on battery and 3334 km on gas. We have used our emergency 5 litre gas can (kept in the frunk) 3 times when we ran out of gas. A fourth time we were able to shut off and restart the car and drive 1 km on battery to a gas station. Gas stations are difficult to find in some rural areas and our 7 litre fuel tank is very small. So we wouldn't travel without spare gas.

Great city car. Not so great for long distance travel. Infrastructure has been poor to nonexistent where we have traveled. In the future our long distance trips will be in our Honda. In over 40 years of driving these recent trips are the only times I have run out of gas.

 

[bwilson4web]

I picked up a 2 gallon, Briggs & Stratton gas can that fits very nicely in the frunk:
https://www.walmart.com/ip/Briggs-Stratton-2-Gallon-Gas-Can/20682774?wmlspartner=wlpa&selectedSellerId=0&wl13=5703&adid=22222222237260393564&wl0=&wl1=g&wl2=c&wl3=108838446030&wl4=pla-127089431072&wl5=9012720&wl6=&wl7=&wl8=&wl9=pla&wl10=8175035&wl11=local&wl12=20682774&wl13=5703&veh=sem

I plan to modify the cap to provide a gravity fed, fuel line to the filler tube just above where it comes into the gas tank with a 1/4" (~16 mm), braided fuel line to a quick disconnect connector. Around town, the can won't be in the car so the sealed connector will be stowed in the frunk.

When we go on a trip, the two gallon, auxiliary can will be filled and put in the frunk, inverted, and connected to the braided fuel line. It will then work like a hamster water bottle. As the gas level in the filler tube goes down, air from the tank will bubble up through the gas line releasing gasoline from the spare can into the tank. In effect, replenishing the tank in a controlled fashion. We're not talking a huge gas flow, just enough to keep the tank topped off.

When this auxiliary tank is dry, the regular tank will begin empty normally so we will know when it is time to refuel.

Refueling will consist of removing the auxiliary can and unscrewing the filler cover. Both the car and the can will be filled and the auxiliary can put back in the car and connected to the braided hose, quick release. Four gallons should provide about 140-160 miles gas range which will significantly improve block time.

Bob Wilson

 

[EVBob]

I picked up a 2 gallon, Briggs & Stratton gas can that fits very nicely in the frunk:
https://www.walmart.com/ip/Briggs-Stratton-2-Gallon-Gas-Can/20682774?wmlspartner=wlpa&selectedSellerId=0&wl13=5703&adid=22222222237260393564&wl0=&wl1=g&wl2=c&wl3=108838446030&wl4=pla-127089431072&wl5=9012720&wl6=&wl7=&wl8=&wl9=pla&wl10=8175035&wl11=local&wl12=20682774&wl13=5703&veh=sem

I plan to modify the cap to provide a gravity fed, fuel line to the filler tube just above where it comes into the gas tank with a 1/4" (~16 mm), braided fuel line to a quick disconnect connector. Around town, the can won't be in the car so the sealed connector will be stowed in the frunk.

When we go on a trip, the two gallon, auxiliary can will be filled and put in the frunk, inverted, and connected to the braided fuel line. It will then work like a hamster water bottle. As the gas level in the filler tube goes down, air from the tank will bubble up through the gas line releasing gasoline from the spare can into the tank. In effect, replenishing the tank in a controlled fashion. We're not talking a huge gas flow, just enough to keep the tank topped off.

When this auxiliary tank is dry, the regular tank will begin empty normally so we will know when it is time to refuel.

Refueling will consist of removing the auxiliary can and unscrewing the filler cover. Both the car and the can will be filled and the auxiliary can put back in the car and connected to the braided hose, quick release. Four gallons should provide about 140-160 miles gas range which will significantly improve block time.

Bob Wilson

I'm really excited to see your progression on this project! I was looking at the same can and was thinking two cans in the frunk, though unpractical from a stop and refuel standpoint since in most places, one should be able to hit a gas station within 60 miles. However with your idea of linking it with the fuel tank - I wonder if two cans did fit in the frunk - if you would be able to set it up so, you have 4 gallons in the frunk so you would end up with 6.4 gallons total - roughly equating to 235 miles gas range?

 

[EVBob]

...When we go on a trip, the two gallon, auxiliary can will be filled and put in the frunk, inverted, and connected to the braided fuel line. ...

Alternatively, you could tap a new hole near the bottom edge and put a quick connector there, that way you wouldn't have to invert the gas tank and take the risk of the larger seal on the cap/top failing and leaking gas?

 

[EVBob]

I picked up a 2 gallon, Briggs & Stratton gas can that fits very nicely in the frunk:
https://www.walmart.com/ip/Briggs-Stratton-2-Gallon-Gas-Can/20682774?wmlspartner=wlpa&selectedSellerId=0&wl13=5703&adid=22222222237260393564&wl0=&wl1=g&wl2=c&wl3=108838446030&wl4=pla-127089431072&wl5=9012720&wl6=&wl7=&wl8=&wl9=pla&wl10=8175035&wl11=local&wl12=20682774&wl13=5703&veh=sem

I plan to modify the cap to provide a gravity fed, fuel line to the filler tube just above where it comes into the gas tank with a 1/4" (~16 mm), braided fuel line to a quick disconnect connector. Around town, the can won't be in the car so the sealed connector will be stowed in the frunk.
....

A bit spendy - but you could go this route and have 5 gallons in the frunk - bringing the total to 7.4 gallons or roughly 288 miles of Gas range:
https://www.amazon.com/Inches-20-Aluminum-Center-Gallons/dp/B00JRJLHF2

 

[EVMan]

In the picture , we see the pipe nozzle on top of the 2 gallon, Briggs & Stratton gas can.
Will the frunk close with the pipe nozzle on top.
Does the pipe come off , so we can close the frunk. ?

 

[bwilson4web]

My current thinking:

• Price-performance - at just over $10 for a 2 gallon can, an affordable start.
• Larger, racing tanks - very nice but pretty expensive. But how much gas range is needed?
• Gas range - there is a case for diminishing returns as the size of the tank grows. It soon reaches human bladder and attention span limits after two hours. Doubling the gas range brings it up to about 2.5 hours which for this old man, is good enough.
• Putting quick-release in other than a fixture in the cap - the problem is we really want the wall in that area to be 2x to 3x thicker to handle any unexpected stress. Worse, it is difficult to work the interior without adopting 'ship in a bottle' technology. The existing opening is already stronger than the rest of the case and well engineered. There remains a question of good washers and seals but these are solvable, especially if the body of the can is suspended so no additional mechanical stress is put on it.
• The spout - is not needed and the spare can is sold with the spout inside and the 'cover cap' on the end. So I'm thinking a flat surface with raised edges towards the interior with an 'interference' fit to the inner diameter of the filler opening. There is already a hole in the screw-on head which appears to have a locking mechanism to avoid rotating to open. If not, it should be easy enough to make sure once screwed down, the head won't loosen.

The main thing is I wanted to share this unique can whose dimensions seem made for the frunk.

Bob Wilson

 

[jadnashuanh]

I doubt the i3's pressurized gas system has very high pressure, but make sure that the can and any attachments to it can handle positive pressure or you'll have a big mess. If I had to guess, I'd guess that the storage area in the frunk is within the crush zone of the car, and not a particularly good place to have a non-engineered stash of gasoline which has the approximate energy content of numerous sticks of dynamite/gallon.

 

[bwilson4web]

I doubt the i3's pressurized gas system has very high pressure, but make sure that the can and any attachments to it can handle positive pressure or you'll have a big mess. If I had to guess, I'd guess that the storage area in the frunk is within the crush zone of the car, and not a particularly good place to have a non-engineered stash of gasoline which has the approximate energy content of numerous sticks of dynamite/gallon.

I agree about the increased risk:

• collision - the auxiliary tank reduces the number of fuel stops and collision risks at fuel stops. For example, our 700 mile trip took 10 fuel stops which would be cut in half. This is one reason for the quick-release, sealing connectors is so the auxiliary tank is removable.
• operational scenario - the auxiliary tank should only be filled when the extra gas is needed upon entry to a cross country segment and when possible, removed and safely stored. The braided metal covered fuel line is meant to reduce risk since chaffing is expected. BTW, around town, the fuel tank should only be partially filled for the same reason.
• leaks - this means paying attention to the filler fitting and minimizing the risks with a well designed sealing mechanism. The bigger problem being cold gasoline that warms up and seeks to expand. So the auxiliary should not be filled and then have the car parked. Fill it and use it, not store it.

I don't have all of the answers. For example, the filler opening needs to be at the highest point when adding gas but become the lowest point when driving without requiring a lot of strength to hold the ~12 lbs of gasoline. So the auxiliary tank should be in some sort of hinged or sliding frame and the frunk space needed remain free to allow rotation.

Also the braided fuel hose routing needs to avoid a loop that might become a 'bubble' trap. The passage of air from the single nipple on the regular fuel filler pipe is critical to getting fuel metered from the auxiliary tank. If this can not be done, some sort of vent tube would be needed.

There may be other design issues that will be revealed during integration and test.

Bob Wilson

 

[EVBob]

There may be other design issues that will be revealed during integration and test.

Bob Wilson

We're rooting for you Bob!

My main interest would be for my upcoming 1300 mile trip - stopping 18 times over 2 days fills me with dread...though this I hope will only occur twice ever (gotta drive back) - your project would be really helpful during the occasional 200+ mile trip.

In the mean time, for folks that have to do a really long drive in their Rex - the best solution so far is to get a speedpass....video of i3 rex refueling time here: https://youtu.be/4ijQ1rJ_YxQ?t=101

 

[EVMan]

FYI
I was able to keep the

No-Spill 1405 2-1/2-Gallon Poly Gas

upright , after removing the tyre kit.

In the plastic category , this looks to be the best....

 

[redbarn]

We've used a Rotopax 2 gallon plastic gas can in our 2015 I3 & now the 2017 I3 for over 2 years now.
No issues whatsoever. It works fine when needed.
I put in fuel stablizer & change the fuel every 6 months (Spring & Fall) if unused.

It gives my wife peace of mind and she has used it although I've never actually have.

 

[EVMan]

You can do your research , but i read, in moving vehicles, only the metal cans should be used.
They can withstand heat , and are more durable.

I am assuming you are keeping your can in the frunk, which is the best location in i3 ,, but still not safe for permanent usage.
I plan to use only for long drives when needed. :arrow:

We've used a Rotopax 2 gallon plastic gas can in our 2015 I3 & now the 2017 I3 for over 2 years now.
No issues whatsoever. It works fine when needed.
I put in fuel stablizer & change the fuel every 6 months (Spring & Fall) if unused.

It gives my wife peace of mind and she has used it although I've never actually have.

 

[EVMan]

Can someone advise, if we need a funnel with deep slim end to put the fuel, or just a small funnel without a deep end will work.
Can someone share their experience ?

When i open the i3 gas tank , i see some metal lid inside, which i suppose will open , with the fuel nozzle is inserted.
What if i use non automotive gas tank .

some thing like the
https://www.amazon.com/gp/product/B000W72GBC
https://www.amazon.com/gp/product/B000W72GBC
The head will not go all the way, and will not open up the metal lid.

Will the fuel easily go inside, or will it be a slow struggle ?
http://www.ebay.com/bhp/no-spill-gas-can

 

[jadnashuanh]

That spring door in all modern cars is sized to only allow an unleaded fuel filler nozzle to fit inside. That flap, unless pushed aside by the nozzle, will create enough backpressure so that a properly operating pump will shut off unless it is inserted through that opening, pushing aside that flap.

If the nozzle on your gas can is long enough and small enough to push that flap aside, it will work to fill the tank.

 

[EVMan]

I read the metal ones have the OSHA and NFPA requirements
http://simplifiedsafety.com/blog/does_your_gas_can_meet_osha_requirements/

You can do your research , but i read, in moving vehicles, only the metal cans should be used.
They can withstand heat , and are more durable.

I am assuming you are keeping your can in the frunk, which is the best location in i3 ,, but still not safe for permanent usage.
I plan to use only for long drives when needed. :arrow:

We've used a Rotopax 2 gallon plastic gas can in our 2015 I3 & now the 2017 I3 for over 2 years now.
No issues whatsoever. It works fine when needed.
I put in fuel stablizer & change the fuel every 6 months (Spring & Fall) if unused.

It gives my wife peace of mind and she has used it although I've never actually have.

 

[MarkNo]

I measured the frunk of my i3, and the back is just shy of the width of the RotpaX 2gal tank and then quickly tapers down to 11" when you are 3" from the back of the frunk - where the leading edge of the 2gal RotopaX would be sticking out by over 2". Is there really enough room at the back of the frunk for the 2gal Rotopax at 13 1/4", even if it is sticking out by 2 or more inches at the leading edge? Is not jammed against the underside of the front hood of the car?

Would it not be a safer bet to opt for the 1gal Rotopax (9.5 x 13.25 x 3") instead?