[Dugaru]

Next question about my new-to-me RV-9A:

It has a Horizon WS EFIS and an EIS 2000. There's certainly a learning curve here compared to my Warrior's six-pack. What's the best way to power these gadgets while I sit on the ground and figure them out?

Currently I have a Batteryminder AGM-2012, which Odyssey apparently approves for use with my 680. So when fiddling with the Horizon gear, I turn off everything other than the EFIS and EIS and leave the Batteryminder connected. But it's a charger, not a ground power unit, and I don't want to damage the battery.

Thanks!
Doug
p.s. I loved my Warrior. A great design and a great aircraft. But let's just say the performance of the RV-9A is.... an improvement in many material respects.

 

[wjb]

For working on the ground, you can disconnect the battery or add a extra contactor for ground power and then feed it with a DC power supply, similar to

http://www.hamradio.com/detail.cfm?pid=H0-004423

(primary use: ham radio; $90)

This one is 9A continuous, which should be fine for the cockpit stuff (glass panel, cockpit lighting, etc). These supplies come in a wide range of current capacities, so you can go up or down in current rating. A typical ham radio supply for a 100W transmitter will put out 20A continuous at 13.8V.

 

[Carl Froehlich]

For working on the ground, you can disconnect the battery or add a extra contactor for ground power and then feed it with a DC power supply, similar to

http://www.hamradio.com/detail.cfm?pid=H0-004423

(primary use: ham radio; $90)

This one is 9A continuous, which should be fine for the cockpit stuff (glass panel, cockpit lighting, etc). These supplies come in a wide range of current capacities, so you can go up or down in current rating. A typical ham radio supply for a 100W transmitter will put out 20A continuous at 13.8V.

I found my 20amp power supply (15 amp continuous) to be on the hairy edged running a dual screen SkyView (will all the stuff connected) and a very power hungry GTN-650. Recommend a 25-30 amp supply. For this application a switching supply will be fine (lighter and cheaper). I never run the panel with any kind of battery charger on line. One of these boxes should be fine: http://www.mfjenterprises.com/Product.php?productid=mfj-4225mv
http://www.mfjenterprises.com/Product.php?productid=MFJ-4128

Carl

 

[lr172]

I use a battery charger for this type of activity and it should not cause any problems for you. A good charger will go into float mode once the battery is charged and won't overcharge.

 

[Raymo]

I concur that a you should have no issues if using a proper charger. The one you have is a 2 amp, from what I could find.

Here is a link to a PDF from Odyssey on recovering a discharged battery but it has other useful information as well.

I run dual Dynon 1000T screens with my BatteryMINDer 128CEC1 charger set to 8 amps and it will still charge the PC680 and the Dynon backup batteries on each screen.

 

[gfb]

I built a simple ground power unit for this exact need:

 

[BillL]

I found my 20amp power supply (15 amp continuous) to be on the hairy edged running a dual screen SkyView (will all the stuff connected) and a very power hungry GTN-650. Recommend a 25-30 amp supply. For this application a switching supply will be fine (lighter and cheaper). I never run the panel with any kind of battery charger on line. One of these boxes should be fine: http://www.mfjenterprises.com/Product.php?productid=mfj-4225mv
http://www.mfjenterprises.com/Product.php?productid=MFJ-4128

Carl

Thanks for the post Carl. I will need a PS soon. I just ordered this one. My 10-friend had trouble with RF noise from a normal charger on his external power connection. This one had good reviews for little to no RF produced, and a good price/amp too.

 

[Dugaru]

Many thanks to everyone for the info.

GFB, it is fair to say that you have more skills in this department than I do. That thing is cool!

The idea that I could whip one of those up from scratch is... well.... preposterous.

 

[Dugaru]

Carl, how would you hook one of these up to the plane?

Assume you are talking to a guy who once hooked a car battery up backwards.*

Thanks
Doug

*I really did manage to do this (long story). My Dad laughed so hard I thought he was going to herniate himself. I didn't blame him.

I found my 20amp power supply (15 amp continuous) to be on the hairy edged running a dual screen SkyView (will all the stuff connected) and a very power hungry GTN-650. Recommend a 25-30 amp supply. For this application a switching supply will be fine (lighter and cheaper). I never run the panel with any kind of battery charger on line. One of these boxes should be fine: http://www.mfjenterprises.com/Product.php?productid=mfj-4225mv
http://www.mfjenterprises.com/Product.php?productid=MFJ-4128

Carl

 

[Ironflight]

Assume you are talking to a guy who once hooked a car battery up backwards.*

Thanks
Doug

*I really did manage to do this (long story). My Dad laughed so hard I thought he was going to herniate himself. I didn't blame him.

Don't feel bad - I once saw this done in the parking lot at work - by a guy who had walked on the moon!!!

 

[Carl Froehlich]

Carl, how would you hook one of these up to the plane?

Assume you are talking to a guy who once hooked a car battery up backwards.*

Thanks
Doug

For my airplane I have a large pin Molex that connects to the Left and Right vital buss after the battery contactors. In other words, the panel comes up but the two master solenoids and vital buss power relays are open. Turn on the power and the panel comes up.

If you have a standard single battery, single master solenoid you can either:
- Connect via a jumper to the output side of the master solenoid. Leave the master off. Power goes to the panel just like it would from the battery. This is the perfected approach. Ir you want to get fancy make a pigtail plug to the master solenoid output terminal and ground so you can just plug in the power supply.
- If you have a fully charged battery, you can try to connect the power supply to the battery. Depending on battery charge, some power will go to the panel and some will go to the battery - just like any battery charger. In this case however the power supply will stay at 13.8vdc, not climb like a charger. Watch line voltage - if it dips or the power supply is pegging out on current, your battery is flat.
- The power supply ground goes to any convenient aircraft ground.

Use #12 wire for both positive and ground leads to the power supply.

Carl

 

[gfb]

Got a couple questions on my parts list, so figured I'd throw it up here.
Box: https://www.amazon.com/gp/product/B005UPANU2/
Box mounting plate: https://www.amazon.com/gp/product/B005UPE83U/
AC outlet/fuse: https://www.amazon.com/gp/product/B00511QVVK/
Panel multimeter: https://www.amazon.com/gp/product/B017BCXQO6/
AC/DC power supply: https://www.amazon.com/gp/product/B00D7CWSCG/
Case fan: https://www.amazon.com/gp/product/B00H8UVJ00/
Temporary connector: https://www.amazon.com/gp/product/B00MYDR1BW/
Final connector?: https://www.amazon.com/gp/product/B01JIVMOE6/

I just realized I don't have a fuse on the DC output, I'd recommend doing that!

Currently I'm just connected to the battery + & - wires without a battery in place. Gotta figure out what the final setup will look like once it's all closed up.

 

[DRMA]

GFB,

Thanks for the parts list. Looks like a nice build for a low cost 30 amp supply, however the reviews of the power supply were certainly mixed.

Please let us know how well it works for you. Would also be interested to know how much RFI/Harmonic Distortion you get with this supply.

According to the specs on the power supply, it is supposed to have overcurrent/short circuit limiting build in, so an output fuse shouldn't be required. However with the reviews of the supply it probably couldn't hurt to add a fuse to the output.

Thanks
Dave M.

 

[gfb]

Haven't had RFI issues, but I really don't use the radio much from inside my workshop

I checked the circuit board for problems or sloppy solder work and it was reasonable for the price. I've been using it a few times a week for the past ~2-3 months with no problems.

As with all cheap Chinese electronics, Caveat Emptor, specially when plugging in to $10k's of avionics.

 

[tmandell]

Just a heads up. Do not use a 3 stage battery charger for providing ground power. The continous current draw will keep the charger in boost mode and will over charge the battery.

I use a special samelex charger at work to create a ups system with agm batteries. A few weeks ago I bought the 30 amp model for $330 canadian. A little steep for a charger but much better that cooking batteries or causing problems with expensive electronics.

Please note if you buy this charge you must read the manual and set up the charger for use with a load.

http://www.samlexamerica.com/products/ProductDetail.aspx?pid=171

 

[Canadian_JOY]

I use this power supply - it allows me to simulate normal operating voltage (~14.5VDC) or run at the nominal setting. This has proven a very capable, quiet and reliable power supply.

http://www.hamradio.com/detail.cfm?pid=H0-013308

 

[mdevans9]

Connection Question

Some of the Ham Radio sourced power supplies have a cigar plug output 7a or 10a (female). I have a panel mounted cigar plug outlet (female) that is properly wired so that I use it to charge the battery (PC 680). Any problem using a male-to-male wire/plugs to connect the power supply for running avionics on the ground in this instance?

Thanks,

Merrill

 

[rv7charlie]

Some of the Ham Radio sourced power supplies have a cigar plug output 7a or 10a (female). I have a panel mounted cigar plug outlet (female) that is properly wired so that I use it to charge the battery (PC 680). Any problem using a male-to-male wire/plugs to connect the power supply for running avionics on the ground in this instance?

Thanks,

Merrill

That'll be fine, as long as you're happy with the new handle of Sparky.
;-)

Seriously, you need some kind of transition connector pair that will minimize the risk of shorting the output to ground. At the very least, you could hurt yourself reacting the the flash and bang of a 30A short to ground.

Charlie

 

[roadrunner20]

I hooked up a two prong automotive plug to my battery and plug into a 12 amp power supply I bought on amazon for $70.
I get access thru the oil filler door.

Works great & is easy to set up for playing around with your panel or doing software/nav db updates.

https://www.amazon.com/gp/product/B00KXGZ2FE/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

 

[rv7charlie]

Dan's on the right path. Even that's on the high end, price wise. I've been really impressed with how much a lot of you guys are paying for ground power. A decent battery charger will do the job just fine. Even if it can't totally keep up with demand, ask yourself how long you're really going to sit in the cockpit pushing buttons. 10 hours? 2 hours? 30 minutes?

In the past, you'd just grab that power supply out of the old PC you're not longer using, and run your toys off the 12V output. No, it's not 14.4 Volts, but neither is your battery if the alternator goes off line. Stuff in the cockpit will still light up and work.

BTW, if your avionics are drawing 20A+, I hope you have a 2nd alternator in your plane, because carrying enough battery to be safe after an alternator failure is going to be tough. A brand new perfect PC680 will last just a bit longer than 30 minutes at that load. 30 Amps? Less than 20 minutes.

Charlie

 

[BillL]

Dan's on the right path. Even that's on the high end, price wise. I've been really impressed with how much a lot of you guys are paying for ground power. A decent battery charger will do the job just fine. Even if it can't totally keep up with demand, ask yourself how long you're really going to sit in the cockpit pushing buttons. 10 hours? 2 hours? 30 minutes?

In the past, you'd just grab that power supply out of the old PC you're not longer using, and run your toys off the 12V output. No, it's not 14.4 Volts, but neither is your battery if the alternator goes off line. Stuff in the cockpit will still light up and work.

BTW, if your avionics are drawing 20A+, I hope you have a 2nd alternator in your plane, because carrying enough battery to be safe after an alternator failure is going to be tough. A brand new perfect PC680 will last just a bit longer than 30 minutes at that load. 30 Amps? Less than 20 minutes.

Charlie

They make too much RF and/or line noise in doing radio interference checks. Hard to check a system when you bring the noise into the test.

 

[roadrunner20]

They make too much RF and/or line noise in doing radio interference checks. Hard to check a system when you bring the noise into the test.

I've not encountered RF issues, but my primary usage is to configure EFIS & upload software & nav db.
The original post was ground EFIS usage & configuration while not using battery power.