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Discussion Starter · #1 ·
I'm wondering if some intrepid Aussie has figured out a way to charge external batteries. I'd like to be able to use my Treg as a big, inefficient generator on long camping trips, to charge the camper's battery. The problem is that the 110-volt outlet in the back only produces around 1-2 amps, which means a lot of idle time to charge an 85AH deep cycle battery. Could I connect my 2500-watt inverter directly to the alternator and thence to my 10-amp multi stage charger? Or would the charged Treg battery prevent full current from the alternator?
 

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Get yourself a DC to DC charger (Cetek 250s or similar) this will charge directly from your cars DC electrical system without converting to AC via an inverter, saving some losses increasing efficiency.

You should also consider wiring in an Anderson plug with a voltage sensing relay to ensure that circuit to charger cut when car is not running (to avoid a flat starting battery). The system would consist of Car battery - Voltage sensing relay with fuse/circuit breaker - Anderson plug socket on back of car - Anderson plug on camper - DC/DC charger - Camper battery.
 

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Same for me, I got a DC to DC charger but where to hook it up?
the OP has a V6 so only one battery, the V10 has 2
I was thinking of connecting the DC to DC charger to the battery under the passenger seat
via an anderson plug, or would it be better to hook up to the rear battery or someplace else?
 

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Discussion Starter · #4 ·
Thanks, that makes sense.
I already have a solar charge controller for the same battery, and it can take up to 70 volts input and charge at 20 amps. Could I connect it to the car instead of a DC-DC charger or is that a bad idea? I understand I would manually switch between solar and car.
I have the same question as Ragman: where to connect in a 2010 TDI: to battery (via Anderson plug) or to alternator or somewhere else?
Bill
 

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I think Loz, the UK forum administrator on www.mytreg.com , has/had a separate battery that he used to charge en route in his V6 Tdi. That battery used to sit behind the passenger's front seat adjacent to the car's own battery tho' he might have moved it as others have fitted a second battery under the spare wheel in the boot/trunk for camping.

I'll see if I can find the links later.
 

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Discussion Starter · #8 ·
Following up with a simple experiment I tried, comparing using the Treg to a standard generator.
One of the most efficient generators, the Honda EU2000i, uses 0.3 gallons of gas per hour to supply 13 amps. By connecting a $20 OBD interface to the Touareg and using Torque on my phone, I discovered that the VW uses around 0.7-0.8 gallons of diesel per hour at idle. It has a 190 amp alternator: over 14 times as powerful as the Honda generator. (Why would any car possibly need 190 amps?) So I could in theory run my 1500-watt Harbor Freight inverter from the alternator to run a battery charger.
 

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Discussion Starter · #9 ·
To really see if this is viable, I need to generate some load on the inverter. The best way to use a lot of electricity is a heater or hair dryer. The next best way is a microwave. I wasn't about to drag a microwave out to the sidewalk, but I do have a heat gun, and a shop vac, which pulls a lot of power. So I plugged both into the inverter (through the Kill-A-Watt, of course), turned them on, and stood back to watch the fireworks.
 

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Discussion Starter · #10 ·
As it happens, the heat gun and shop vac overloaded the inverter, and it just switched off, instead of going up in ball of fire. Oh well, at least I got the Treg carpets cleaned for the first time in 6 years.
The bottom line is that it's viable to use your Treg as a generator. The 20-amp DC charger mentioned by the other poster will do a great job, but I need to use an inverter because I'm charging both LiFePo4 and lead acid batteries at the same time. A 2500-watt inverter costs less than a 2500-watt generator, and your Treg is going to be much quieter at idle than most generators. And if you have a diesel you don't have to carry 2 kinds of fuel--diesel generators tend to be really big and not portable. Obviously you wouldn't want to let it idle for hours at a time so you would want sufficient capacity to charge quickly. My main charging source is solar so it's unlikely I'd have to idle for more than a half hour.
 

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Discussion Starter · #11 ·
Incidentally, I thought it would be fun to be the only person who's ever charged a Nissan Leaf from a Touareg, but the Leaf charger seems like it didn't like the modified sine wave output from my cheap inverter, and wouldn't charge.
 

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A 190 amp alternator, at 12v nominal, puts out 2280 watts (190A x 12V) while a Honda EU2000 puts out 2000 watts - so nowhere near 14x as powerful.

If your 13A is based on a 110V output then comparing it with a 12V output is your error.
 

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Discussion Starter · #13 ·
Good point. I was comparing 12-volt alternator output to 110-volt generator output. Also good to know that my existing 2500-watt inverter is a decent match for the alternator output.
 

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Following up with a simple experiment I tried, comparing using the Treg to a standard generator.
One of the most efficient generators, the Honda EU2000i, uses 0.3 gallons of gas per hour to supply 13 amps. By connecting a $20 OBD interface to the Touareg and using Torque on my phone, I discovered that the VW uses around 0.7-0.8 gallons of diesel per hour at idle. It has a 190 amp alternator: over 14 times as powerful as the Honda generator. (Why would any car possibly need 190 amps?) So I could in theory run my 1500-watt Harbor Freight inverter from the alternator to run a battery charger.
My R5 uses .9 litre per hour at idle, that's more than .8 gallon ph.

Does your alternator put out 190amps at idle?
Probably not.
Have you tested the fuel use under full electrical load?
 

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.9 L/hour = .24 gal/hour
.8 gal/hour = 3 L/hour
 

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Following up with a simple experiment I tried, comparing using the Treg to a standard generator.
One of the most efficient generators, the Honda EU2000i, uses 0.3 gallons of gas per hour to supply 13 amps. By connecting a $20 OBD interface to the Touareg and using Torque on my phone, I discovered that the VW uses around 0.7-0.8 gallons of diesel per hour at idle. It has a 190 amp alternator: over 14 times as powerful as the Honda generator. (Why would any car possibly need 190 amps?) So I could in theory run my 1500-watt Harbor Freight inverter from the alternator to run a battery charger.
I don't think this is a fair comparison. Your alternator might put out 190 amps under the best circumstances, and idle is far from that. Have you measured its current output at idle?

I have also considered using the Touareg as a generator for an camper trailer, but between the risk of coking up the EGR valve and clogging the DPF, I've decided against it.
 

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Redarc

I'm wondering if some intrepid Aussie has figured out a way to charge external batteries. I'd like to be able to use my Treg as a big, inefficient generator on long camping trips, to charge the camper's battery. The problem is that the 110-volt outlet in the back only produces around 1-2 amps, which means a lot of idle time to charge an 85AH deep cycle battery. Could I connect my 2500-watt inverter directly to the alternator and thence to my 10-amp multi stage charger? Or would the charged Treg battery prevent full current from the alternator?
I have fitted a 12 Volt 80 AH battery into a Battery Case along with a Redarc 12 Volt 6 amp DC DC Charger plugged into the 12 Volt power socket in the rear luggage area. When the ignition is turned on the Power socket is on and the Redarc starts charging the battery. When the Ignition is off the Redarc isolates the Aux Battery. I run a 12Volt Fridge off the Aux Battery
 

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I have fitted a 12 Volt 80 AH battery into a Battery Case along with a Redarc 12 Volt 6 amp DC DC Charger plugged into the 12 Volt power socket in the rear luggage area. When the ignition is turned on the Power socket is on and the Redarc starts charging the battery. When the Ignition is off the Redarc isolates the Aux Battery. I run a 12Volt Fridge off the Aux Battery
Fair enough, but . . .







































. . . is the beer COLD??
 
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