Earth X battery problem

Having had to jump start my 8 in Dayton a few weeks ago, I decided it?s time to replace my 7 year old well abused PC680. I bought an EarthX EX680 and put it in the airplane yesterday. Took a little ?adjusting? with a long screwdriver to the stock Van?s firewall mounted PC680 battery box, but I got it in without too much effort.

When I went to turn on the master switch however, the solenoid clicked, the instrument lights flashed and everything went dark. The LED on the EarthX was on steady. I went through the manual and it says that it?s possible a short would kick the battery into self preserve mode.

I hauled out my ships electrical architecture schematic, (Bob Knuckoll?s figure 13) and gave it a bit of thought. Thinking possibly something in the main buss might be causing a problem, I switched on the E-Bus without the main. Everything came up, went back to the battery and the led was dark, threw the master on and it all stayed on. Turned it all off, turned the master back on, click and dark again. The led was lit again. ???

In a while, even though the led was on, I was able to power up again by first turning on the E-bus and then the master. When I left, the led was still lit.
Went back today. Led was out, powered up (E-bus first), went fine. Turned it off flipped the master first and it worked, turned it off and back on and it went dark again. Roh rho?.

Checked the voltage. 13.12V Put the charger on it on a 15 Amp charge rate. Charger said full in 15 minutes. 13.7V. Flipped the master, all good. 6 more times, all good. 8th time, click and dark again. This time the led was short flashing. 2 minutes later it was clear and I could power up again, E buss first. Cranked the starter successfully a few times all ok. Cycled power again and it went black again.

This is weird to me and I first suspect the battery. I have no other similar vehicle to put it in to verify the problem is the battery though.
I have flown the airplane 330 hours with the PC680 so I don?t really suspect there is anything wrong with the electrical system, but I would like to ensure the problem is the battery, not the ship. The only thing that crosses my mind is that I used bi-directional Zener diodes from Parahelion designs on the master and starter solenoids to control field collapse spikes instead of the standard diodes called for and I?m wondering if their behavior might have something to do with what the battery electronics are sensing. This however is a total shot in the dark as I am not an electrical engineer, I don?t play one on TV and I didn?t sleep at a Holiday Inn Express last night.

So I?m wondering if someone might have some idea of what to look for or if I should just be calling EarthX. Admittedly I already would have but they?re not open till Monday morning, and you folks are here 24-7!

I upgraded to an EarthX900 recently. I spent a lot of time figuring out this new battery stuff. First of all, are you using a charger specifically approved for the EarthX? Even if you are, the computers in the cells and the one in the charger take a lot of time communicating, it is not like in the old days when you could hook up a charger and start it a few minutes later. Wait until you run it clear down and have to get it back up again. A real challenge!.

I installed a EarthX EX680 about a month or two ago and during the installation I accidently shorted the positive terminal to the airframe and the LED light came on with no power from the batter available for about 5 minutes. After a bit of reading, I learned that this is normal and it is as a result of the built-in protection. The battery has worked just fine since. I suspect there might be another issue with your system, very possibly the bi-directional diodes.

bi-directional Zener diodes

disconnect them from master contactor and try

I wouldn't use them on contactor or starter solenoid

I've got a NIB EX680 in the hangar if you want to swap it out and eliminate the battery itself as a suspect. It's on the shelf over the bench by the sink.

Follow up

Thought I'd post a follow up to this thread.

I called the EarthX folks and they had their engineer follow up. Sent him my electrical architecture schematic and he couldn't see anything there that might be giving the battery grief. Satisfied that my ship was likely ok, he had a new battery sent out. Installed it last night and all is good.

Great service by this company. If your on the fence I'd say go for it. Their support is great!