Originally Posted by Pistolera

As I go about disecting the wreckage I don't think I've ever seen a plane so totally destroyed (without a fire). It hit in a perfect vertical nose-down attitude in a cornfield.

The Biela 26x10 prop acted as the speed brake as the rest of the plane tried to drive itself through it. Pic below shows the results....I can't imagine the force required to punch the center out of the CF prop and aluminum spinner backplate .

Surprisingly the DA120 doesn't have ANY exterior damage, but was shipped back to DA today.

Dang....unreal...

Originally Posted by tande

Does anybody use this? .....sold by a very reliable source.....just wondering....

I use one of these for checking my A123's. It measures out to the 100th of a volt which is helpful with the finite voltage change from charged to dead of the A123's and shows each cell individually. It also has a discharge/load cycle for measuring the amount of charge left. The directions state anything less than 3.3V per cell is no go. While I do not rely on this load test completely as to how much fuel is left in the pack(I go by the mah used per flight) it does give me piece of mind. With my limited flying time, I am lucky if I can get two flights in during a flying session, so I am not pushing the batteries to their limits. My experience, take it for what it is worth.
Travis

Another cool tool could be the booma switch. It measures how many mah is drawn from each battery and it gives you the voltage of each battery
http://www.boomarc.com/en/booma-rc-intelliswitch-1-1

Originally Posted by Pistolera

As I go about disecting the wreckage I don't think I've ever seen a plane so totally destroyed (without a fire). It hit in a perfect vertical nose-down attitude in a cornfield.

The Biela 26x10 prop acted as the speed brake as the rest of the plane tried to drive itself through it. Pic below shows the results....I can't imagine the force required to punch the center out of the CF prop and aluminum spinner backplate .

Surprisingly the DA120 doesn't have ANY exterior damage, but was shipped back to DA today.

That is a keeper. I have never seen anything like that in my life. Talk about center punch. You need to take those parts and make a collage. Great story piece!

Originally Posted by Huckin Chuck

Another cool tool could be the booma switch. It measures how many mah is drawn from each battery and it gives you the voltage of each battery
http://www.boomarc.com/en/booma-rc-intelliswitch-1-1

While handy- unless you know that you are fully charged to start it's not foolproof. You are counting down how much capacity you are using- but you still don't know for sure what's left in the tank....

Originally Posted by parpar1

That is a keeper. I have never seen anything like that in my life. Talk about center punch. You need to take those parts and make a collage. Great story piece!

I'll make a memorial in my trailer

Originally Posted by dmichael

While handy- unless you know that you are fully charged to start it's not foolproof. You are counting down how much capacity you are using- but you still don't know for sure what's left in the tank....

Exactly. All of my A123 packs are now relegated for ignitions and powering my fueling pump!

I've been wanting to go to 7.4v anyway, so now's the time.

All of my A123's were used as filler material in the dumpster.

Went with 3800 mA Lipo from Thunder Power With Castle BEC Pro regulators.

Just wow

Sorry man. I lost my custom SHP when I forgot to put n the stab bolts. I lit the 'remains' it on fire.

Goodbye S5-DPS (1 min 26 sec)

Dang...don'tcha just hate that! You did a fabulous job on it too!

I am also an A123 user and have an identical setup to yours (2 x 2300mah packs). I decided against 7.4v because of the need for regulators. Now that we have things like the Tech aero and we can get all 7.4v compatible servos this is no longer an issue. Maybe its time I switched.

I could us a telemetry system to solve the in flight data problem which would give you a warning if something is draining the pack prematurely. I prefer that over checking before every flight.

It stinks to "upgrade" your thinking through hard lessons....especially on a nice plane like that.

Currently, I'm sold on straight and simple 2s lipo setups...no regulators....HV servos all around....voltage check both packs before EVERY flight...fly from a starting voltage of over 8v down to about 7.4v...then swap out packs...I've got several sets of inexpensive lipos...2s-3800's or 4000's for 100cc and larger.....2s-1800's for 50cc.....and in 33cc I just run a single non-redundant 1800 pack.....but I LOVE being able to know whether I can fly by the total pack or individual cell voltages....they have not lied to me yet. The key to this easy to use setup for me is to have multiple packs...and just swap em out all day long....every 4-6 flights...for hot ones straight off the charger. I suppose I just got used to strapping in LIPO packs with velcro straps from smaller electric planes...but it's so easy for RX power in the bigger stuff.

Good luck on your next build Earle!! I can't wait to see how it turns out.....

And...I'd be interested in the "bill-of-health" on your 120 once DA get's done with it....just curious if any damage was actually done....and what DA had to do on it to make it new again....keep us posted.

I had 2 2300 A123s in my 35% for about 6 flights, I recharged after 3 flights and I felt that the capacity was too low for that size airplane. Rather than put 4600s in I went back to 5200 lions. I keep the A123s for 50cc and smaller planes now.


Rick

Dang, just read through all the current posts on this....too bad! I have A123's (hangtimes or EdNano) in all my planes and so far no problems other than I had one set in a plane go totally dead from August to April hanging in the garage (they are doing great on my fuel pump now). I do always balance charge and typically not more at than 2amps or so after every 3-4 flights. I have had a couple that get the cells out of balance (and don't want to come back into balance) and they start to act up and run down faster so they get tossed.

I may have to start looking at going to HV, but I have too many planes and too many servos to start replacing them all Regulators maybe?