Litium battery question

[jiott]

I'm going to give a reply that is admittedly not very expert, but I believe the Rotax generator is good for about 21 amps with no problems. The problem is much more likely to be the Ducati voltage regulator. I have heard that much over about 13 amps for a prolonged (whatever that means) period of time can overheat and damage or reduce the life of the regulator. If I were you, I would figure out a way to limit the charging amps to less than the 18 you mentioned. My 912uls system with the EarthX 680C never draws more than 10-11 amps charging and my regulator lasts a long time. Just my 2 cents.

[Shadowrider]

Mike I have never read or seen a max alternator output time limit. 18 amps output on a good day and full power is what the stock will put out. It takes about 30 min into the flight before I will normalize my battery volts at 14.1. Edge Performance has a graph I remember seeing for the stock versus the aftermarket one they sell. I will see if I can find it. But based on your description I would have to agree that everything seems normal. You wont see 18 amps until your fully power. Just FYI I know a couple that will never see normalized voltage unless they turn off all the lights. (So they are running the alternator at max entire flight)

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[Delta Whisky]

Mike - here's a link to my go to page on the Rotax alternator. HTH. http://contrails.free.fr/elec_alt_rotax_en.php

[DesertFox4]

EarthX with the fancy charger. Never needed to leave on the charger and by the rules at my airport, couldn’t leave it on any charger unattended. The Battery Management System works as advertised. The warning light will blink in the appropriate “ pattern” for any fault it might detect. Pushing two years now and still the cheapest weight reduction I employed on my build. Also the quickest starts I’ve experienced on a Rotax engine.

[jiott]

4+ years with EarthX battery. Never have left the charger on. If I rarely need to charge it (like if I do a bunch of avionics testing with the engine off) I just use an Aerovoltz lithium charger that I already had.

[buckchop]

How about in cold weather, say -10, -20, anyone been there yet with a cold start on the battery after u warm up motor if u have a 0235 lycoming in a KF5, The new battery i just put in her is 400cca, myB&C starter/alt paperwork says 300cca minimum, and im not impressed with off brand battery i bought at $125, should have got a better one. But could b the long run of cable from tail to motor, i want to remove it from the tail and move it closer to motor.

[Denalifox]

+1 for EarthX. Had one in my Cessna 120 and it sat for 5 months in the Alaskan winter. Fired right up in the spring. Also run one in my STi.

[PapuaPilot]

I'm also using an EarthX and don't charge it.

I would avoid other brands if you think you are trying to save money. The EarthX has dual BMS built into the battery. There are a lot of lithium batteries out there you could buy for less, but they probably don't have a built in BMS. That is what is going to save the battery from a thermal runaway, over discharge and over charge, etc. If you ever over discharge a lithium battery there is no way to recharge it, you just throw it away.

[Jerrytex]

Which model earthx battery? Rotax 912uls.

[DesertFox4]

ETX680


$379.00

or



ETX680C

$379.00


I installed the ETX680
with Kitfox Aircraft’s nice battery box for the
EarthX ETX680. I think the ETXC will fit in their battery box too.
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