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Ground Power vs Trickle Charger connection

AviatorJ

Well Known Member
One of my 45 items of unknowns is if I'm going to do ground power or just have a connection for a trickle charger... or both.

I've read a number of previous posts on the subject but I'm not sure I grasp it in it's entirety. It seems ground power is best used to jump start the plane and run avionics without the engine turning. If I ever need to jumpstart the plane with the battery being in the back seems easy enough to get to it without a ground power socket. However since I plan to go full glass I would like to configure and mess with the avionics without having the engine running.

Last annual I installed a battery tender and dongle on my 172 and it was really painless and is easy to use. Would like to do the same but would I still be able to run the avionics with the tender attached or would it pull power faster than charging, either damaging the battery or forcing a long recharge period before starting the plane?

Weight is a bit of a concern for me since I'm installing an AC unit back there. Would it make since to just have a dongle for the trickle charger and then buy something I can physically attach to the battery while testing or configuring Avionics?

Thanks!
 
My opinion:

I have found the ground power outlet on my Cherokee to be very useful on several occasions. I intend to install a ground power outlet as well as an option for trickle charging on my -10.

The trickle charger jack can be mounted in the baggage area and won't take up much weight at all. The ground power outlet should be easily accessed from outside the airplane in a safe location should jump starting be necessary. You don't want to have to try to jump start an airplane by stringing temporary cables to the battery. Of course you should always be thinking (especially in an all electric airplane) "is it really smart to jump start this thing? What do I plan to do once it's running?"
 
You will get lots of opinions on the subject and each will have reasons for tailoring their configuration to a specific need or certain anticipated circumstances.
If your biggest concern is running your electronic equipment and spending
time configuring and tinkering with your avionics, you really don't need a ground power plug. An easily accessible cigarette lighter plug or designated plug for a trickle charger would be more than enough.
Your fully charged battery will keep your electronics running for a considerable amount of time while you configure avionics and after that exercise you can simply recharge your battery via charger, trickle or other.
If you anticipate flying to remote places in cold climates with a weak battery,
you might be better off installing a ground power plug. You'll add quite a bit of weight and complexity with such a heavy duty plug.

My installation includes a designated plug in the baggage compartment for a
trickle charger but heavy enough wiring to accommodate a regular battery charger, not enough to jump start the engine though.
 
I did install pigtails for the trickle charger (Battery Tender) in our 10.

When doing the EFIS config work, I just plugged in the trickle charger, and turned on the battery master.

I have spent hours doing the config work, never had a brown out.

I suspect if you start with a hot battery, and the charger going, you will be just fine for pretty much you want to do with ground setup.

P4190049.jpg
 
I have a pig tail for a trickle charge just like Mikes. It goes through the Flightline Interiors panel and is a snap to plug in when needed. I also have a standard auxiliary power plug (cessna style) right next to it for jump starting and glad I did because I needed it once away from home and a nice man at the airport pulled his truck through the gate and gave me a jump. Thats accessible by removing a small cover on the trim panel.
 
Appreciate the responses and it answers my question. I'm not overly concerned about jump starting the plane, again if it happens I can take the panel off to get to the battery. I'll just plan on having an interface kit for my batteryminder much like what I have on the 172.

On using a standard battery charger do you just use alligator clips on the battery itself?

Also Mike notice you have a Main and Aux charger. Do you run two batteries in your 10?
 
I went the simple, straightforward route with a trickle charger extension accessible through the oil fill door. I'm in the habit of opening the door anyway after a flight to let the heat escape more quickly.

I did that on the 172, because I do the same and the battery is up there. My RV-10 battery will be in the back and don't like the idea of running a line all the way to the front for it.
 
Also Mike notice you have a Main and Aux charger. Do you run two batteries in your 10?

Yes, I have dual batteries, dual alternators.

Odyssey 925 and 60a alternator make up the main system, 680 and 8a alternator make up the backup system.
 
Yes, I have dual batteries, dual alternators.

Odyssey 925 and 60a alternator make up the main system, 680 and 8a alternator make up the backup system.

Thanks, assume you run electric ignition. Looking into that is on my 45 item list... Hoping by the time I get to that someone releases some type of E-mag for the Lycombing 540.
 
> "This is for a Schumacher float charger, but you get the idea:"


That Schumacher "float charger" is a POC that will ruin your battery in short order if you leave it on for any length of time. A hangar neighbor had one and went through a table full of Gills and Concordes and never did realize he was ruining his batteries with that Schumacher junk.

How do I know? He became disabled and I got his plane airworthy enough to ferry and wondered about all the dead batteries he had collected over the years. I put a voltmeter on the Schumacher float charger and found it was pumping 15+ volts into the battery on a continuous basis.

I have a Schumacher full size charger bought at Sears that has a "Maintainer Mode" on it and thought it might be a good thing to use as a battery maintainer for the motorhome. After checking my hangar neighbor's Schumacher and discovering what it was doing I checked my Sears charger and found out it was doing the same thing. 15+ volts. Continuously.

It overcharges and overheats and ruins batteries if you leave it on. It's fine as a charger. It's death to batteries if used as a maintainer.

The Battery Tender is probably OK. I haven't used one but I think we would have heard if they weren't any good. What I use is a Pro-Logic PL-2140 Intelligent Charger. $50 on Amazon.

If you don't believe me get your multi-meter out and just look at what the Schumacher **** is doing.
 
If you really believe you need to have external power to run the panel on the ground, get a real power supply. I do not run electronics with any kind of battery charger/tender/maintainer connected.

A nice 20 amp regulated power supply is not expensive - and what should be used anytime you are running avionics on the bench. You can make a "ground connection" to plug this in for extended panel time in the plane: http://www.hamradio.com/detail.cfm?pid=H0-004429

As previously stated, if you are connecting a charger to your battery put a voltmeter on it and monitor what it is doing. Do not leave a charger on a battery unattended.

If you are thinking about jump starting a plane with a flat battery, think again. If you can breath life back into the abused battery with a charger and then use the battery without the charger to start the engine, fine - but the battery should be considered compromised and whatever reserve capacity you thought you had is suspect.

Carl
 
> "As previously stated, if you are connecting a charger to your battery put a voltmeter on it and monitor what it is doing. Do not leave a charger on a battery unattended."

In a perfect world that's good advice. If a person IS going to do it though - for instance because it's minus 10 degrees in the hangar for weeks at a time or for whatever reason people think putting a maintainer on the battery is necessary, make sure it's a good one. Sears/Wally-World stuff is not anything to leave on a battery for longer than it takes to bring it to a full charge - around 13 volts including the surface charge.

The little "$6.99 on sale" battery maintainers they sell at Harbor Freight are actually better for long term use than anything with the name Schumacher, et. al. on them. It's foolish perhaps, since it's possible they could short out or do something weird, but at least they will bring the battery up to 13.1 and keep it there. They won't overcharge - which is what the other ones do that I've mentioned. It's the overcharging that overheats the batteries, boils out the fluid, warps the plates, and turns them into junk.

I'm guessing the Battery Tender brand is okay. I know for sure the Pro-Logic charger/maintainer I use is safe. Safer still though is to not leave anything connected to the battery but in really cold climates you pretty much have to. Freezing temperatures for extended periods is not good for batteries, as I understand things. Probably better to take the battery out in that situation and take it home. Keep it warm and charge it once a month.

I have an 55 Ah AGM in my plane. They like a very slow charge. Flooded cell, AGM, Gel-cell and Li-Ion all have different charge needs . . . which is why I like the Pro-Logix intelligent charger. It handles each type differently. Mine is the small one, PL-2140 and works beautifully. I keep an eye on it with a voltmeter and have learned to trust it so far. Pro-Logix makes larger ones but the small one has been fine for the plane, motorhome, bike and cars. If left on for really extended periods - over a week - they'll shut down and wait until the battery voltage drops to a certain point before coming back on. They will also do a de-sulfating mode if left on for weeks at a time - in other words, after about a month or more of being left connected to a battery, they will draw current down on the battery then take the charge up to a high number to knock the sulphate off the plates, then bring the voltage down to a maintenance level then shut off again.

That little cheapo from Harbor Freight has also been good over the years. It never charges higher than 13.1. It doesn't do any of the fancy stuff like I just mentioned but it will keep a battery at 13.1 and never take it higher. I used one for years and it never did anything weird. The battery I used it on lasted almost 8 years. $6.99 on sale. They are not for use with a badly discharged battery. The battery needs to have at least 11 volts in it before connecting one of these HF maintainers. If you're careful about that, these little inexpensive things are fine and will keep your battery healthy for many years . . . that's been my experience.

If you have something with the name Schumacher on it, or one with a different name that is probably made by the same company, don't trust them as I've found they overcharge, overheat, and destroy batteries in short order, no matter what they say in the book that came with it. Use a voltmeter on them and you'll see.

I agree it's not good to play with your electronics with a charger hooked up to your battery. I've read cautions against doing that. I don't know enough about how it all fits together to know why it's not a good idea, but I've read it's not, so I don't do it. I'll just use the ships power if the battery is at a full charge. Once the electronics are turned off, I'll put the maintainer or charger back on the battery to bring it back up to full.

Here's the one I use. Pro-Logix have higher amperage maintainer/chargers for about the same price but this one has been fine for everything I've needed it for.

http://www.amazon.com/SOLAR-PL2140-PRO-LOGIX-Battery-Maintainer/dp/B00U3ZBU2E

It was recommended to me by a battery expert so I took the advice and it's been good.
 
I'll just use the ships power if the battery is at a full charge. Once the electronics are turned off, I'll put the maintainer or charger back on the battery to bring it back up to full.

Works for me...

I plan on using the new BatteryMinders when they come out... I'm still a year or so from Avionics.
 
Any reason a trickle charger can,t be run thru a ground power plug?

At least on my Cherokee, the ground power plug is wired so that when power is applied to it, it pulls the master contactor closed independently of the master switch. The battery is completely out of the circuit until the battery switch is closed. Thus there is no way, in that wiring scheme, to trickle charge a battery through the ground power outlet unless a) the trickle charger has enough power to hold the master relay open and b) the battery switch is closed.

To trickle charge from a ground power outlet, it would have to be wired directly across the battery which would make it hot at all times. In that case, you'd still need to manually activate the master switch to get power to a main bus from the GPO. To avoid that, one would need to design a circuit that can connect the GPO to only one of the battery or the master relay at a time. All this leads me to the conclusion that two different jacks, each with a dedicated purpose, is the simpler option.
 
Easiest thing to do for me is to pull my battery I have in my archer. Takes me no more than two minutes and instead of sitting on the ramp where it's 10 degrees, it sits in my basement where it's 65.
 
Any reason a trickle charger can,t be run thru a ground power plug?

That's what I do. I hook up the ground power plug so it is directly connected to the battery, and I've never had a problem with this. I out e grind power plug on the belly right by the battery. I make a little "dongle" with a mating connector for the Piper style plug so I can gator clip the trickle charger (battery minder) on or I can hook up jumper cables. This has come it handy on numerous occasions. I can also hook up a Shumacher style charger for working on avionics on the ground.
 
That's what I do. I hook up the ground power plug so it is directly connected to the battery, and I've never had a problem with this. I out e grind power plug on the belly right by the battery. I make a little "dongle" with a mating connector for the Piper style plug so I can gator clip the trickle charger (battery minder) on or I can hook up jumper cables. This has come it handy on numerous occasions. I can also hook up a Shumacher style charger for working on avionics on the ground.

Jesse, I'm curious: how do you ensure that when ground power is connected, that you are not applying an excess voltage tot the battery? Also, it seems like you are subject to the failure mode of forgetting to disconnect or power off the ground power outlet and having full voltage applied to the battery continuously.

It sounds like a convenient method which is why I am interested, but how do you ensure safety and battery condition?
 
That's what I do. I hook up the ground power plug so it is directly connected to the battery, and I've never had a problem with this. I out e grind power plug on the belly right by the battery. I make a little "dongle" with a mating connector for the Piper style plug so I can gator clip the trickle charger (battery minder) on or I can hook up jumper cables. This has come it handy on numerous occasions. I can also hook up a Shumacher style charger for working on avionics on the ground.

Jesse that sounds really interesting. Do you have any pictures or drawings of how this is all put together? To me it sounds like you have some larger gauge wire connected directly to the batter terminals and terminated on one of those piper style plugs.

When I installed the dongle on the 172 I just used a common ground and put the positive on the master relay I assume to protect the battery.
 
24V protection?

I have a Cherokee too. I don't think there is any way to protect the power plug input for a 24V. power cart. It pulls the relay, the diode to the master pulls the external relay, 24V applid externally will blow the battery/system if master is on. But, if 12V is applied externally, it is a safe system. Can't charge externally though.

Maybe I ought to go look at the schematic again.....it's been awhile...
John
 
Jesse that sounds really interesting. Do you have any pictures or drawings of how this is all put together? To me it sounds like you have some larger gauge wire connected directly to the batter terminals and terminated on one of those piper style plugs.

When I installed the dongle on the 172 I just used a common ground and put the positive on the master relay I assume to protect the battery.

That's all based on the charger used, just as if the rear baggage wall was off and you had a charger hooked up to the battery. I prefer the Battery Minder that will charge up to 8 amps, but will top off the battery and go into maintenance mode automatically. They have units that are specifically calibrated for Concorde, Odyssey, Gill, etc. they also have 12 and 24 volt chargers.

The Shumacher type charger I will use when I am in the plane, but I never leave it connected overnight. They also will somewhat smart charge, only putting out what they need to put out to maintain the voltage, but I still don't use them overnight. I also never use a setting over 10 amps.
 
For what it's worth regarding trickle charging/battery tender, the Concorde RG-25XC I bought in 2010 and first flew in 2011 is still going strong--never needed a charger, even sometimes going several weeks between flights. I use the cigarette lighter in the panel and a 10A power supply to run the panel for software updates, etc, and it also can feed the battery when the master switch is on.

-Rob
 
Take a look at these connectors

That's what I do. I hook up the ground power plug so it is directly connected to the battery, and I've never had a problem with this. I out e grind power plug on the belly right by the battery. I make a little "dongle" with a mating connector for the Piper style plug so I can gator clip the trickle charger (battery minder) on or I can hook up jumper cables. This has come it handy on numerous occasions. I can also hook up a Shumacher style charger for working on avionics on the ground.

Our battery is on the firewall, so the best option for us was to put the charge/jump plug inside the oil door. I found these anderson connectors that are much smaller than the piper or cessna plug, plug they isolate the power line very nicely. I used high quality welder cable to run it over the battery and ground. Used the extra welder cable to make a ground plug that we carry in the plane with open pigtails, that way we can use any charger or battery to charge and even jump in an emergency.

http://www.andersonpower.com/_global-assets/downloads/pdf/ds-sb120.pdf
 
> "The Shumacher type charger I will use when I am in the plane, but I never leave it connected overnight. They also will somewhat smart charge, only putting out what they need to put out to maintain the voltage, . . ."

If you've put a voltmeter on that "Shumacher type" charger to see just what voltage it's putting out when in its "somewhat smart charge" mode, then you know what it's doing and may have reason not to distrust them as much as I do. I've really only monitored two Schumachers when in "maintainer mode" so I'm not wise enough to condemn them all, but I sure would be suspicious :)

The battery specialist I bought my most recent AGM from was horrified at the mere mention of using an ordinary charger with "maintainer mode" on a battery. It was thanks to him that I actually put a voltmeter on the Schumacher car charger I'd bought at Sears and saw what it was putting out when selected for "maintainer mode." It was over 15 volts continuous.

It was about the same time that I got involved with helping my hangar neighbor and saw his table full of ruined batteries in the back of the hangar. He had been using a small Schumacher model (picture attached). I put a voltmeter on it and sure enough, same thing. He had been very diligent in using it, thinking that in keeping his battery connected to this device he was prolonging the life of his batteries - despite the fact he had a table full of ruined ones. He's 87 but had obviously been unable to put two and two together for many years.

*******

Well, guess I can't post a picture. It's a small nice-looking little thing that says Schumacher Speed Charge on the front.
 
Don't get me wrong. I never leave that type of charger connected. I will only use it at all to keep battery voltage up when running the panel on the ground. The voltage in this mode never reaches anywhere close to the 14.3 or so that I get when running the alternator. Usually it just keeps me in the 12.7-8 range so I don't drain my battery.
 
Another perspective...

I have been following this thread with interest. I have been using battery tenders on all of my equipment for years and have never had ANY issues with damaging batteries. I use the tenders on tractors (lead acid), snowmobiles (lead acid), ATVs (AGM), Ultralights (AGM), and a Cessna 172 (AGM). During the winter months the tenders are left connected; summer months, not so much. The tenders on the AGM batteries are the plus model, rated for AGM type batteries. I have yet to have to replace the tractor battery (10 years), the snowmobile batteries usually last 3-5 years and the last battery I replaced in the Cessna was 7 years old. Can't vouch for the Schumacher brand by I have had good luck with battery tender brand...obviously YMMV...
 
I think the various models with the name Battery Tender is okay from what I've seen and heard. Costco sells them, or has in the past. I've seen them widely sold and never heard anything bad.

For that matter, the Harbor Freight cheapo battery maintainer will do just fine in my experience. It's the overcharging that kills the batteries. The HF maintainers I've had have been trustworthy over years and never takes voltage higher than 13.1. It's only the fact they cost so little that makes it scary.

These VRLA batteries (valve regulated lead acid) are all sealed and can't deal with overcharging. Nor can plain old flooded cell batteries like Gills. With the sealed batteries the overheating causes them to release electrolyte through their escape valves which degrades them while the plain old flooded cell gets electrolyte boiled away exposing the plates.

I was really suprised at the behavior of these common battery chargers/maintainers like Schumachers and others of equivalent type. The companies that make them certainly aren't stupid, yet they let those things get sold all over the place that put out 15+ volts continuously in maintainer mode. I was amazed to find that out. Why do they do that?

All I'm really saying here is if you're using a maintainer, put a voltmeter on it and make sure you know what it's doing, no matter what the brand.
 
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