Schauer Charger Cooked Batteries

[LTek1]

Okay, I have now ruined two batteries by leaving my Schauer charger plugged into the GPU port - master switch on, battery breaker pulled. The Schauer literature says it is a "smart charger" that can stay connected for long periods as it will automatically stop charging.

The first battery I roasted was when I first got the plane 7 years ago. I assumed I had made some kind of newbie error, like having the selector from Flooded to AGM set wrong, or some wrong combination of breakers or something.

But I did it again last month; came to the hanger to start getting the plane in shape for spring. Engine would turn, but wouldn't catch. Left the plane on the charger, and came back 3 days later to a battery that was completely dead. Shop put it on their fancy conditioner and couldn't get it to take a charge at all.

So, I am going to buy a 24v Concorde battery minder; that's all well and good, and everyone seems to love them.

But was there something I could have been doing wrong with the Schauer? Or is the charger just bad?

[AndrewM]

Having been an owner for two DA40s over the last 7 years, I have never had the plane on a charger and never had any battery issues.

Current battery in the plane I think is over 5 years old. May change it next fall as we move into winter as a precaution but I think you could consider not hooking it up to a charger, unless of course playing with the G1000 in the hanger or something like that.

[LTek1]

Unfortunately I often go 3 or 4 months without flying, with the interference of Life, the Universe, and Everything. Arriving at the airport to a too-low-to-start battery is a common enough occurance for me, so in the times I do manage to break free for a few hours, it would be nice to know the battery is topped off.

[gyro3816]

I have that same charger but I only use it to ground power avionics (or charge battery as backup).
I use my batteryminder religiously. Its the only thing I trust for conditioning / trickle.

[Boatguy]

I also have that charger, purchased about three years ago. Last month I accidentally left it connected for about 5 days and had no problems when I returned.

At my annual in March the shop desulficated (is that a word?) my battery and that boosted the standby voltage about .5v.

[perossichi]

that's de-sulfating. This is what Battery Minder claims to do -- sending pulses of current so that sulphur crystals formed on battery plates dissolve.

I note that there is some skepticism regarding whether or not this actually works.

However, my own experience does confirm it -- when I moved from a tiedown (no battery minder) to a hangar, my Concorde batt was 2 years old. I did something like a capacity test and found the battery was marginal -- about 85%. After a year on the battery minder, capacity up to 95 per cent or so.

I even bring my battery minder with me on trips. I left the lights on in KLLR and the battery minder actually recharged the battery in about 2 hours. It attempts a deep discharge and it works.

I don't have any experience with Schauer but I now have two battery minders -- one for each Concorde in my Col 400.

[Lou]

I bought a Schauer initially but then I did some research and determined that it would probably cook the battery. I was able to sell it and bought a Concorde Battery Minder. No issues since then. I use a harness, not the GPU port. There are reasons for this that I have forgotten but it seems to be a preferred practice.