I am new to the electric world. I bought two new 800 mAH 8.4 V batteries for the Aerohawk and charged them afresh with my Piranha charger. One gives me ~1 minute of flight before it is dead and the other ~2.5 minutes. What in the world is going on? I have the correct settings on the charger and have the delta peak senstivity at 8. It seems the worse pack only takes in about 150 mAH and it is done charging. Please give some advice if you can. Thanks in advance!

you need to slow charge them the first few times....if you can, charge them at .1A...this will "open up" the cells...they wont reach full charge capability for a few cycles...if they still wont work you probably have a bad cell and should send them back.

Thanks for the advice. Will do. Gosh, slope soarers were so much easier!

Which model Piranha do you have? Are you sure it can be set to give you only ~80mA charge rate for slow charging. Otherwise you might have to cycle them several times by discharging them down to 1v/cell, then recharging them using the 50mA trickle charge capability - but that will take 20hrs or so to charge them each time [at 80mA it will still take ~14hrs].

Cheers, Phil

It is the Piranha digital peak charger with no discharge capability. They told me witih NiMH there is no need for discharge. Anyhow, the lowest I can go to charge them is 0.1 A or 100 mA. That is it. Any other suggestions here? Thanks!

do the slow charges at .1A...a little high but better than quick charging them...for discharge just hook them up to plane and run at 1/4 throttle (thats the easy way...hard way is build a discharger out of auto bulbs)

ucsdgemini

I had the same problem with 2 Aerohawk packs. My question to the experts out there is, can I use a wall wart designed for nicad rx and tx packs at 9.6v and 4.8v for a new nimh pack trickle charge 7 cells 8.4v. What I want to do is charge a new pack on the tx side at 9.6v and 50ma. First, is the voltage too high, and second, can I get into trouble using a nicad wall wart on nimh's.

David

Ok, now I am fed up. I slow charged my packs as described. My 2 new 800 ma packs actually took in all 800. But, everytime I got to fly my Aerohawk, I get 30 seconds and then caput, the thing falls out of the sky. Why am I having such difficulty with these things? Am I missing something?

I had the same problem with mine. I actually got 2 new packs and am in the process of seeing if these work better. If they don't, I am going to assume that there is something wrong with the Aerohawk.

Where did you get your Aerohawk from?

Give me this info and I'll run some #'s thru motocalc for you. Need motor size & manufacturer, esc and prop. I'll give you a ball park estimate of time you should be getting...it may be that those packs are being sucked dry very quickly. Either that or a bad cell. How many times has the pack been charged & discharged? It takes a little while for the cells to open up.

Everything is stock for an Aerohawk. One of my packs last longer. It is definitely a pack issue. I charged one with the stock charger overnight and I got 45 seconds out of the damn bird. I am so sick of these batteries. I think I will go LiPoly.

sounds like you have a dead cell or a bad connection inside the pack...I'd send it back.

Problem is I got it from RCmart in Hong Kong. Took forever and a day to get. I won't even bother for the ten bucks. Thanks for the help.

If you know how to make your own packs you could easily check to see if one or more of the cells was faulty, buy a replacement and rebuild the pack. If you dont want to mess with it and are gonna throw it away or something send it to me I'll take it.