SonexBuilders.net

For those of you who installed lithium ion batteries (spevifically aerovoltz)to save some weight you may want to take a look at this thread over on the POA forum. I'm sure all lithium ion batteries aren't the same but there is risk to implementing new technology. This could have had a very bad outcome if it happened in flight.

https://www.pilotsofamerica.com/communi ... es.102016/

Keith
#554

Scary, I've got one of those installed...

PS. these are actually lithium iron batteries (also known as lithium ferrous phosphate).
Whilst they are not as efficient, they are supposed to be more stable than lithium ion batteries, obviously not stable enough.

I have a volt meter & ammeter installed, looks like I'll need to watch them all the time for any signs of overcharging.
I also have an alternator cut off switch which might come in handy.

I have the EarthX battery and have had no issues over the past year. Unlike the battery mentioned in the link above, the EarthX has internal circuitry that prevents it from fully discharging or over charging.

http://earthxbatteries.com/our-batteries

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"This battery comes with advanced technology to protect it from over-discharge, the number one killer of all batteries. If your battery reads near 0 volts, the over-discharge feature has been activated, thus your battery must be charged. If you left your lights on, key on, have a faulty stator, or have a parasitic drain this can easily happen. Our BMS is designed to disconnect the flow of current in the event of over-discharge (internal disconnect switch is opened). Many smart chargers will not attempt to charge a low voltage battery (below 9V). If this happens, there are several ways to charge the battery.

1. The easiest way is if you have the Optimate lithium charger. Simply connect the alligator clips first, plug in the charger next, and the save mode will come on and start charging it.
2. Another method is to connect your charger to the EarthX battery as normal, then put either a jump pack or another 12V charged battery in parallel with the EarthX battery so the charger will read it’s voltage and engage. Once the charger sees voltage it begins to charge as normal. After 5-20 seconds you can remove the jump pack or jumper cables (being careful not to disconnect the charger). Recharging this battery from the depleted state can take from a couple hours to overnight. To watch a video of how to do this, go to: http://www.youtube.com/watch?v=6o-YYpy9hYU"

They talk about one not holding a charge and another getting warm... I wonder if they had these batteries ganged together? Unbalanced cells or a big differential in charge state could cause current to flow from one battery to another, depending on how they're wired together. And over-charging (or charging at too fast of a rate) is a main source of trouble for Lithium batteries.

--Noel

NWade wrote:They talk about one not holding a charge and another getting warm... I wonder if they had these batteries ganged together? Unbalanced cells or a big differential in charge state could cause current to flow from one battery to another, depending on how they're wired together. And over-charging (or charging at too fast of a rate) is a main source of trouble for Lithium batteries.

--Noel

Keep in mind that the sonex puts out a constant charge when the engine is running. It is no different then having a charger constantly hooked up while flying. To Mike's point, the earth x batteries have some circuitry that is supposed to protect the batferies from over chaeging. The lithium batteries are not all made the same. I just know that there was previous discussion on the forum about the aerovoltz batteries and that some had installed them.

Keith