Don't make the same mistake I made...

[wiztecy]

I have the Griots charger also, and ran into blowing fuses when I used it with my Lotus Evora a few years back. So I carried extra fuses and just ignored it. I have since put it in my Roadster, but didn't really think about testing it in the lighter socket, but I would assume it may be the same issue based on what others are saying.

Would it make sense to carry something like the following?
battery-cigarette-lighter-extension on Amazon

I don't know how easy or difficult it is to get to the small 12V battery under the front passenger fender, but this seems like it might work much better getting the power directly from that battery. Thoughts?

If you want to hook directly up to your 12v battery, I'd use the battery tender wire connection below. That way you can disconnect it. It also has an inline fuse.

Battery side:
Amazon.com: Battery Tender 081-0069-6 Ring Terminal Harness with Black Fused 2-Pin Quick Disconnect Plug: Automotive

Plug with the cigarette lighter that you can keep in your trunk:
Amazon.com: Battery Tender 081-0069-8 Female Cigarette Adaptor for Quick Disconnect: Automotive

 

[AltPowr]

If you want to hook directly up to your 12v battery, I'd use the battery tender wire connection below. That way you can disconnect it. It also has an inline fuse.

Battery side:
Amazon.com: Battery Tender 081-0069-6 Ring Terminal Harness with Black Fused 2-Pin Quick Disconnect Plug: Automotive

Plug with the cigarette lighter that you can keep in your trunk:
Amazon.com: Battery Tender 081-0069-8 Female Cigarette Adaptor for Quick Disconnect: Automotive

I agree, this would be a cleaner option - however in looking on the BatteryTender website they state the fuse is 7.5 amps. Wouldn't that be a worse option than the 12 amps in the Roadster outlet?

 

[wiztecy]

I agree, this would be a cleaner option - however in looking on the BatteryTender website they state the fuse is 7.5 amps. Wouldn't that be a worse option than the 12 amps in the Roadster outlet?

You can email "Battery Tender" and ask them if the wire will support the amp draw of your compressor, also ask what gauge wire they're using. If yes, then you can safely install a higher rated fuse. The nice thing is that you'd be going directly to the 12v battery and not through the Roadster electrical system.

It appears the motorcycle community has succeeded in putting in a higher rated fuse to run compressors and inflating pumps. I'd do a couple of dry runs to ensure the wire doesn't get hot or cause a short:
Using a 10-15 amp fuse with a Battery Tender? : V-Twin Forum: Harley Davidson Forums

 

[AltPowr]

Ah, cool, I will look into this - thanks! I think this would be much cleaner of a way to go.

 

[spaceballs]

Good point and thanks for the heads up about the compressor and overdraw on the AMP current on the roadster's cigarette lighter. Anyone know why it was set so low at 12 amps? The lowest amp draw for a DC based air compressor is 15 amps which I'm sure will blow the fuse.

Looks like I'll be searching for a small rechargeable one. Have to pay attention at the reviews, it appears some of these rechargeable units don't have enough amp hours in the battery to really do the job if you're stuck on the side of the road. I see that some people are modifying and upgrading the battery packs on these things, and after that mod they work pretty well. I may just use my spare motorcycle sealed gel battery and one of my battery clamp on style air compressors.

Worse case is that I keep the 20AMP compressor in the car as an emergency, if I really was in a pinch and cars are around I could borrow their DC outlet for a few minutes. Something is better than nothing.

Now that I'm thinking of it, why can't I tap off a 20 AMP direct DC connection or custom connection to the dedicated 12 Volt battery that's housed in the front of the roadster? I may just go that route. Makes sense to me, not limited to burning up under-rated circuits, unknown roadster wiring, and can wire and be limited to my own direct fused circuit. I just built my battery pack and high output compressor up in my emergency duffel bag and I don't like the extra weight at all as well as the space it takes up....

I'm never like the idea of having another 12v AGM battery that will die in just a few years. You could always try tapping into the roadsters 12V power system in front of the right rear tire. Also if your worried about electrical noise going back to the roadster, then use large inductor, diode in series, and another diode for back emf.

 

[hcsharp]

I'm never like the idea of having another 12v AGM battery that will die in just a few years. You could always try tapping into the roadsters 12V power system in front of the right rear tire. Also if your worried about electrical noise going back to the roadster, then use large inductor, diode in series, and another diode for back emf.

+1. I'm also more worried about damage from electrical noise than over-amping it.

 

[spaceballs]

+1. I'm also more worried about damage from electrical noise than over-amping it.

Proper filtering is always a good idea. BTW the the onboard ESS to 12v converter can do ~2,000 watts, so ~160 amps not counting other Roasters 12v electrical systems.

 

[wiztecy]

I'm never like the idea of having another 12v AGM battery that will die in just a few years. You could always try tapping into the roadsters 12V power system in front of the right rear tire. Also if your worried about electrical noise going back to the roadster, then use large inductor, diode in series, and another diode for back emf.

I was under the impression AltPower wanted to tie into the 2.x 12v battery that's located ahead of the passenger side front tire, not add another 12v battery source: "I don't know how easy or difficult it is to get to the small 12V battery under the front passenger fender, but this seems like it might work much better getting the power directly from that battery."

If he's just using it for a compressor, that shouldn't introduce any noise. Also he can disconnect the cigarette lighter prong so only a short +/- 6" to 10" lead hangs off the batt.

AltPower PM'd me and indicated the Battery Tender wire is 18AWG, looking at the chart below as long as you keep your total wire length to 10 feet, it appears it will hold up to a 15AMP draw / fuse. For a 20AMP draw/fuse you need to keep the total run down to 5 feet or under. **Note to also include the wire length of your compressor for that its the total run of wire that the electricity has to travel across which adds resistance and causes heat:

Wire Gauge Amps Ratings for 12 volt Automotive Systems

 

[spaceballs]

I was under the impression AltPower wanted to tie into the 2.x 12v battery that's located ahead of the passenger side front tire, not add another 12v battery source: "I don't know how easy or difficult it is to get to the small 12V battery under the front passenger fender, but this seems like it might work much better getting the power directly from that battery."

If he's just using it for a compressor, that shouldn't introduce any noise. Also he can disconnect the cigarette lighter prong so only a short +/- 6" to 10" lead hangs off the batt.

AltPower PM'd me and indicated the Battery Tender wire is 18AWG, looking at the chart below as long as you keep your total wire length to 10 feet, it appears it will hold up to a 15AMP draw / fuse. For a 20AMP draw/fuse you need to keep the total run down to 5 feet or under. **Note to also include the wire length of your compressor for that its the total run of wire that the electricity has to travel across which adds resistance and causes heat:

Wire Gauge Amps Ratings for 12 volt Automotive Systems

Remember the ESS does charge the 12v aux battery, so electrical noise still can feed back to the ESS. Actually the best plan would to use the 12v Aux battery directly but disable the APS in the VDS menu, this might help prevent any noise going back to the ESS.

 

[wiztecy]

Remember the ESS does charge the 12v aux battery, so electrical noise still can feed back to the ESS. Actually the best plan would to use the 12v Aux battery directly but disable the APS in the VDS menu, this might help prevent any noise going back to the ESS.

Ok.

So the DC to DC converter does not act like a filter in any way? I'm curious what's preventing noise from coming in from the Aux. power socket. What are the negative effects on the ESS from noise?

 

[spaceballs]

Ok.
So the DC to DC converter does not act like a filter in any way? I'm curious what's preventing noise from coming in from the Aux. power socket. What are the negative effects on the ESS from noise?

The ESS 12v DC-DC has it's own basic filtering on it's output, I was just being paranoid as it's be one expensive system to replace if it somehow (even though unlikely) get damaged from any spikes on the 12v system. If anything from what I've read on the fourms here that it seems that the 12v switch pack be the most sensitive device on the 12v rail.

I haven't seen how the 12v acc socket is wired up yet, so I have no idea if there is any filtering. I do know that I can back feed power in to turn on the VDS though (without an ESS connected) in order to run some basic tests.

 

[wiztecy]

The ESS 12v DC-DC has it's own basic filtering on it's output, I was just being paranoid as it's be one expensive system to replace if it somehow (even though unlikely) get damaged from any spikes on the 12v system. If anything from what I've read on the fourms here that it seems that the 12v switch pack be the most sensitive device on the 12v rail.

I haven't seen how the 12v acc socket is wired up yet, so I have no idea if there is any filtering. I do know that I can back feed power in to turn on the VDS though (without an ESS connected) in order to run some basic tests.

Good point with vulnerable switchpack, its one reason why I chose the rechargeable compressor route.

 

[AltPowr]

Correct, I was only looking to connect to the 12V battery ahead of the passenger tire for a minute or two only if I really needed to use the compressor - in other words I would have just patched a flat. Based on what I saw, that the accessory socket supposedly has a 15A fuse, I would plug the compressor into it first, and if it doesn't blow the fuse, then no issues. I'm just looking for a quick and dirty alternative at the side of the road if needed. I would hope that I may never have to even try it. That's why I'm thinking large alligator clip style connection may be the best since the plan is to never really do it.

 

[hcsharp]

The ESS 12v DC-DC has it's own basic filtering on it's output, I was just being paranoid as it's be one expensive system to replace if it somehow (even though unlikely) get damaged from any spikes on the 12v system. If anything from what I've read on the fourms here that it seems that the 12v switch pack be the most sensitive device on the 12v rail.

I haven't seen how the 12v acc socket is wired up yet, so I have no idea if there is any filtering. I do know that I can back feed power in to turn on the VDS though (without an ESS connected) in order to run some basic tests.

The DC-DC converter is somewhat sensitive to noise on the output. The owners' manual mentions there are restrictions on the type of devices (not just load size) you can plug into the 12v port in the cabin. Without searching for the posts, a couple of TMC members had to replace theirs after plugging a dirty load into it. The switchpacks are also very sensitive and Tesla replaced a lot of the early ones. The later cars were not immune to this issue.

 

[smorgasbord]

Has anyone checked out this non-compressor alternative?

It's also available from PowerTank directly without the CO2 cylinder, so you could attach a 9oz or 12oz cylinder instead (I'm thinking the 9oz would be fine). Add a plug kit and you're as set as you can be.

Should we be worried about carrying the CO2 cylinder in the trunk of Roadster? If so, would half-filling it reduce the risk?

- - - Updated - - -

There's also the DynaPlug motorcycle air compressor. Apparently older BMW bikes have really sensitive electronics (CAN bug issues) and have low amperage fuses. The DynaPlug unit is designed to not draw more than 6 amps under load. Yeah, it'll take a while to refill, but for the one time in 5 years you need it, that shouldn't be a problem.

 

[slcasner]

What do you do about sealing the puncture before using the compressor?

 

[wiztecy]

Coming from scuba diving experience, that pony tank can be filled to 3,000 psi, with that the most vulnerable part of the tank is the neck where the top (silver neck) gets sheared off in an accident. Then after that it's a rocket. Filling it half way will reduce its energy but still a projectile. Its not that cost effective since scuba tanks cost $$ which this is a pony tank, also it will have maintenance subject to scuba tanks and fill regulations. Visual $18-$35 visual check is required every year and a $50 Hydro inspection is every 5 years. Also its funny they call it a CO2 tank, it possibly is an empty CO2 tank but its not getting pumped with CO2. Just odd advertising.

The second link, the 6amp motorcycle pump sounds key. Now you made me look, I have a 2004 BMW R1150GS Adventure motorcycle that came with a mini pump. So I just checked it out, 10 amps , only $30 and has 4.5 stars out of 5 in the reviews with 21 people reviewing it.

Amazon.com: Airman C60A54 Tour Pump Air Compressor - Compact size with cigarette plug: Automotive

Its very very compact. I'll start using that one since it reduces the cargo footprint in the truck. I also unscrewed the DC plug, it has a strait plug in there, solid that's the size and length of a standard log style fuse. One could carry a bunch of 10AMP fuses, put on in the DC head, and that should blow before the 12AMP Roadster accessory fuse.

 

[smorgasbord]

What do you do about sealing the puncture before using the compressor?

Dynaplug sells a liquid-less plug system

There's also something like the Safety Seal System

(start at about 5 mins in)

 

[wiztecy]

What do you do about sealing the puncture before using the compressor?

Carry a plug kit and low profile scissor jack (as well as lug wrench/breaker bar). But even if you don't have the plug kit, the air will buy you miles to the store / gas station if its not a bad puncture.

 

[smorgasbord]

the air will buy you miles to the store / gas station if its not a bad puncture.

That's what the Roadster included Slime style can is for, no?