Ground Power vs Trickle Charger connection

[MikeS]

> "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.

[Carl Froehlich]

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

[flyinga]

I've got an external power plug on my Bonanza. Haven't used it in the 13 years I've owned it.

[MikeS]

> "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-P.../dp/B00U3ZBU2E

It was recommended to me by a battery expert so I took the advice and it's been good.

[AviatorJ]

Originally Posted by MikeS

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.

[bob888]

Any reason a trickle charger can,t be run thru a ground power plug?

[1001001]

Originally Posted by bob888

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.

[cderk]

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.

[Jesse]

Originally Posted by bob888

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.

[1001001]

Originally Posted by Jesse

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?