Z50A-600 on TRex 600 on 15s A123 cells pinion needed

[dfrazier]

I just purchased my batteries and am about to order everything else. I would like to know what PINION would be necessary to achieve about a 2200 rpm headspeed.

I am going to be using the CC85HV ESC and want to run it in governor mode between 75% and 85% as I have read this is where the esc needs to be set so it has some head-room to maintain headspeed.

I know these batteries are being talked about all over the place and I have searched but I cannot find what info I need.

[Ticidytoc]

14T,15T,16T and see what works best for you. the 15Tshould be close for your 2200 HS.

[dfrazier]

Thanks,
I will give them a try.

[Cryofix]

Hopefully Mr. Mel can chime in here, he has an awsome head speed calc available for A123 cells, however I can not find the link right now.

I am running 14 S with a 12 tooth on an Actro 24-3, dialed down to give me 2200 HS, please remeber when using A123 cells there is a much larger voltage sag once you start using these batteries, so you have to compensate for the sag. Ordinary calculations for a LiPo will leave you wanting more from these batteries.

I would suggest 12 or 13 tooth especially for a lower KV motor

[remie]

I also would like to step to a123, but I'm wondering how you charge your 14s packs?
my tp1010 only does 10 cells?

[dfrazier]

2 chargers

[csell]

Hello

I am a newbee with a T-Rex 600 that flew for the first time one week ago.
My schulze isl 6-330d charger kan charge a 123 pack up to 13 cells.

For the moment I just have 1 FP 4900 pack and are considering what to bay next.
Can any tell me how the T-Rex 600 will fly on a 13 psc. a123 packs?

Regards Carsten

[Cryofix]

I also would like to step to a123, but I'm wondering how you charge your 14s packs?
my tp1010 only does 10 cells?

Mastech 50 volt 20 amp AC/DC converter with a wattmeter. I can do 14S up 35.98 volts, or I just use my E-Station 902 to charge my 4S pack and the Mastech to charge the 10S pack.

Taking it easy on my batteries, I charge them at 12 amps, about 11-13 minutes of charge time.

I set the mastech to 36.5 volts, which is .5 volts over charge, so the CV portion of the charge winds down quicker.

The Mastech is only an AC to Dc converter but.... will drop to CV after the CC hits 36.5 volts, so it is simillar to a charger.

[kgfly]

MrMel's calculator is here: http://www.dacsa.net/heli/Calculator/default.aspx

Cool idea about using the Mastech CCCV power supplies as chargers. Two good choices:

Single 0-50V/20A (very high rate charging of up to 14s2p):
http://shop.vendio.com/Evan2002/item/818330695/?s=1183802402

Dual 0-50V/5A (2C charging of up 2 x 14s1p or 1 x 28s1p):
http://cgi.ebay.com/NEW-MASTECH-DC-POWER-SUPPLY-DUAL-VARIABLE-0-50V-0-5A_W0QQitemZ250140289917QQihZ015QQcategoryZ32720QQ cmdZViewItem

[kgfly]

Cryofix - you said:

Mastech 50 volt 20 amp AC/DC converter with a wattmeter. I can do 14S up 35.98 volts, or I just use my E-Station 902 to charge my 4S pack and the Mastech to charge the 10S pack.

Taking it easy on my batteries, I charge them at 12 amps, about 11-13 minutes of charge time.

I set the mastech to 36.5 volts, which is .5 volts over charge....

Why can't you do 14s at 50V (ie ~3.57V/cell) ? That would get you somewhere over to 95% charged wouldn't it ?

It looks like you split your pack and charge as 10s @ 36.5V and the 4s in parallel on another charger, is that right ?

[Cryofix]

Cryofix - you said:

Mastech 50 volt 20 amp AC/DC converter with a wattmeter. I can do 14S up 35.98 volts, or I just use my E-Station 902 to charge my 4S pack and the Mastech to charge the 10S pack.

Taking it easy on my batteries, I charge them at 12 amps, about 11-13 minutes of charge time.

I set the mastech to 36.5 volts, which is .5 volts over charge....

Why can't you do 14s at 50V (ie ~3.57V/cell) ? That would get you somewhere over to 95% charged wouldn't it ?

It looks like you split your pack and charge as 10s @ 36.5V and the 4s in parallel on another charger, is that right ?

I can do that but its faster to split charge, because you drop into CV to top off the battery for much longer than you can actually draw CC, 3.65 volts gets you a shorter charge time while geting 95% cap

[tungym]

600kv may be a bit low.

I ran Z50-780kv with 14s A123, 14T/188 helical, CC85HV, throttle@governor 90%, pitch +/-13 deg, HS ~2100, Eagletree reads 2400 W@60A peak. This will just squeeze all the juice of A123, with temp ~60 deg Cel.

14s A123 cannot deliver the power for the full potential of Actro, which can give 3000+ W.