Flat battery considerations

[jaredyates]

If you had purchased a pc680 4 years ago and left it on the shelf, I think it would be dead also, though probably earlier in the 4 years. The lower self-discharge is a real advantage if you don't fly the plane for several weeks, but I don't think there is a sealed battery of any type that we would expect to last 4 years without any attention.

[rodsmith]

I put a pc680 in my motorcycle. I didn't ride for 4 months over the winter and the battery was dead and unrecoverable. I thought the discharge rate was low enough that wouldn't be an issue. I purchased another one 6 years ago and keep a trickle charger on it over winter. Still going strong. I suspect the first battery might have had an issue.

[bearhawk2015]

I started flying my airplane with a pc680 and went through 2 of them. I would be lucky if I could get 2 years out of one. This is with a 540 engine, I’ve heard other people with large 6 cylinder engines replace their pc680 at every annual. I switched to an earthx and haven’t touched it since which was 4-5 years ago.

[Gary Wallace]

Is there an earthx physically the same size as a pc680??

[jaredyates]

The etx900 and etx680 are the same dimensions as each other, and very close to a pc680. Probably interchangeable depending on the style of mounting.

[bearhawk2015]

My pc680 also seemed to give out at the worst places, like a grass strip in the middle of nowhere or some lake in Canada where
you’re on your own. Luckily I always had a jump pack with me to get it going.

[aerolithium]

alternative battery

[Battson]

I missed the first start on my -540 last weekend, having not flown for a month. The PC680 is 4 years old and flown every fortnight at least. It didn't have enough legs to have a second start attempt, it would have started with mags but the EI needs a faster spin or it kicks back (yeah, go figure). So I missed my second start too. Then I had to jump it with a second 680, which really made it spin

The PC680 has never let me down when flown regularly or given a maintenance charge if not. This is only the second time it wouldn't start - always the winter on the 4th or 5th year of battery life.

Next year is when the PC680 shines vs ETX, replacement cost

I tried to hand prop it first, but I overestimated the fuel burnt so gave it one second of priming. I later discovered my mistake and how flooded it was. Don't double prime if you are hand-propping. Wait for it to fire.

[whee]

While we are on the topic of batteries and PC680s, has anyone experienced a 680 leaking battery acid? I’m doing my annual and found corrosion on my firewall. It’s clearly from some kind of corrosive liquid and it left a corrosion trail that started at the battery and ran down the firewall onto the lower boot cowl and tunnel. It has to be the battery but I can’t find any signs of a leak or damage on the battery itself.

[Battson]

Current leaking and tracking, especially through a medium, could cause corrosion.

[Light&Sweet]

On hand propping: I would recommend practicing ( hot and cold starts) with your aircraft using accepted practices to develop your own procedure and stick to what works when it is needed. Waiting until you HAVE TO hand prop is the wrong time to learn what is needed. I have been flying my ‘46 Champ (A65, no electrics) for 5-years and hand propped the old girl hundreds of times which has taught me the finer points of what I need to do to start that airplane.

[alaskabearhawk]

Interestingly enough, my four year old EarthX battery came back to life. I used the recommended procedure from the EarthX web site to trick the Optimate LiFePO4 battery charger to coax it back. Just to be completely clear, my ETX900 battery is NOT recommended for this procedure. Kathy at EarthX strongly recommended against it. I have a battery that is labeled as an E8 (series?), EarthX says the recommended procedure for attempting to resurrect batteries is for those labeled 7 and under. Numbers 8 and higher, don't do it.

I figured I had nothing to lose since the battery was on the way to the recycle bin anyway. In case the battery wasn't going to survive the event I did it outside in an area where nothing would be harmed and would tolerate a medium-sized crater, even though I don't know what would have happened if it wasn't successful. It took a couple of tries of "tricking", but eventually the battery charger went through it's paces and brought it back. The battery never got hot, nor did it change shape.

I am not going to use this in my Bearhawk. I put a big label on it for "BENCH USE ONLY". I'll use it to power up my instrument panel as it near completion to check things out and have a source of DC power for testing other things that need DC power.

I took a hard look at the Aero Lithium battery. If I hadn't already purchased all the extras from EarthX for the installation I probably would have given them a try. I spoke with Andy at Aero Lithium and he was very nice and knowledgeable. I ended up getting a replacement ETX900 from EarthX. Of course, I put it on the charger right out of the box. I don't want another expensive repeat of this experience! YMMV

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[Nev]

Glad to hear you got it back to life. It might be a good backup to carry on overnights. I left my master switch on one night during the avionics installation and found the battery flat next morning - the BMS had disconnected it. It took quite a few attempts of "tricking" it into life. However since then it's never missed a beat and packs a decent wallop.

[aerolithium]

For the person so inclined to try something new: I'll make the 1st battery - 12ah - for the 1st person $200 with a 30 day no questions asked guarantee.
I'll introduce myself in the new member section