Power supply for iPad charging.

[Rich]

Has anyone tried plugging in a dual USB port charger into the cigarette lighter 12V port? While the fuse is 3A, it is unclear whether that is at the 28V level or converted to 12V already. A prior post comments whether Diamond just didn't replacard, or they actually downgraded the wiring, which sounds unlikely, when the went from 28V port toe 12V port. Assuming the 3A fuse is at 28V, a dual 2.4 Amp charger plug should be fine. Anyone running such a plug in the outlet (not installed a new accessory port)?

This works fine. The accessory port is the plane's system voltage and is wired directly to the hot bus. There are adapters that work just fine for this purpose at 12-28 V transparently. I used a couple of different ones before removing the port in favor of a Stratus USB adapter connected to the avionics bus. But when you use this accessory port don't leave anything plugged into it with the plane parked, as it's always hot and you'll be draining the battery.

[greg]

Has anyone tried plugging in a dual USB port charger into the cigarette lighter 12V port? While the fuse is 3A, it is unclear whether that is at the 28V level or converted to 12V already. A prior post comments whether Diamond just didn't replacard, or they actually downgraded the wiring, which sounds unlikely, when the went from 28V port toe 12V port. Assuming the 3A fuse is at 28V, a dual 2.4 Amp charger plug should be fine. Anyone running such a plug in the outlet (not installed a new accessory port)?

This works fine. The accessory port is the plane's system voltage and is wired directly to the hot bus. There are adapters that work just fine for this purpose at 12-28 V transparently. I used a couple of different ones before removing the port in favor of a Stratus USB adapter connected to the avionics bus. But when you use this accessory port don't leave anything plugged into it with the plane parked, as it's always hot and you'll be draining the battery.

Not all DA40s have the accessory port at the plane's system voltage - my 2007 has a 12V port. And my recollection is that the fuse is on the output side of the DC-DC converter - it's a pico fuse quite close to the cigarette lighter port. So the 2A rating is probably at 12V, not at the original 24V. (I had to replace one when another pilot decided that it couldn't possibly be a 2A limit - the air compressor he plugged into it ran for precisely one second before the fuse blew.)

But as Dave mentioned above, if the USB charger is rated at 2.4A each output (rather than input) you may be ok - at 5V that's less than 20W. It would depend or the efficiency of the charger, though, and whether you draw the full rated power from it.

[Rich]

Not all DA40s have the accessory port at the plane's system voltage - my 2007 has a 12V port. And my recollection is that the fuse is on the output side of the DC-DC converter - it's a pico fuse quite close to the cigarette lighter port. So the 2A rating is probably at 12V, not at the original 24V. (I had to replace one when another pilot decided that it couldn't possibly be a 2A limit - the air compressor he plugged into it ran for precisely one second before the fuse blew.)

I stand corrected. Looking through the various wiring diagrams I found this in one labeled in part: "12V Aux Plug" with this interesting detail:

Also this variant is not powered off the hot bus, but the main bus.

[smoss]

so if the fuse does blow, is it actually soldered inline, or just easy to change under one of the 3 caps aft of the battery area?

[greg]

so if the fuse does blow, is it actually soldered inline, or just easy to change under one of the 3 caps aft of the battery area?

Neither. It's a pico fuse soldered to a pair of spade terminals, surrounded by clear shrink-wrap. It's behind the panel (ie the glare shield needs to come off to get to it), near the cigarette lighter port. It can be removed fairly easily without tools. Your options would then be to order another assembly from Diamond, or get a pico fuse and terminals and make your own.

[smoss]

OK, so checked my plane today, and first off, the 12V plug is not on the hot bus, it is indeed controlled by the master, and second, luckily I do have a 3A fuse labeled Acc Pwr (or something similar) easily accessible via the oil filler access door which is a standard glass fuse, even in the IPC as MDL-3. I guess at some time they changed the setup.

[Rich]

OK, so checked my plane today, and first off, the 12V plug is not on the hot bus, it is indeed controlled by the master, and second, luckily I do have a 3A fuse labeled Acc Pwr (or something similar) easily accessible via the oil filler access door which is a standard glass fuse, even in the IPC as MDL-3. I guess at some time they changed the setup.

Check again. The same wiring diagram that depicts the 12V plug also shows the 3A fuse still in place but connected to nothing:

I suggest removing this 3A fuse and checking whether the 12 V plug works or not with it removed.

[smoss]

Rich, as suggested, I removed the easily accessible 3A Aux Pwr fuse, and indeed, the cigarette lighter outlet still works! Bummer.

[dmloftus]

During my annual a couple months ago, I had the standard cigarette lighter in my 2008 XLS replaced with a higher capacity version from Aircraft Spruce. Also disconnected the 2A fuse, had the wiring upgraded, and run through a 7.5 amp breaker connected to the avionics bus. Easily enough power to run a decent PC, but intended to run a 100W oxygen concentrator if the battery is expended. I already had 2 twin stratus usb ports, one on each side of the panel to run iPad, iPhone.

[smoss]

Does anyone have the exact specs of the pico fuse? Fast acting or slo-blow? I was going to order a spare, and Mouser has like 50 varieties of the 3A pico.