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View Full Version : Where to buy a 270mah nimh square rcvr battery?


ransom peek
01-07-2007, 06:20 PM
The plans for the electric Chrysalis 2 meter sailplane (link below) call for a 270 mah nimh square reciever battery. Does anyone know where to buy this battery? I am ordering from the Tower catalog but can't find one, so my need to go elsewhere...

The manufacturer of this plane recommends use of thie separate battery instead of using the esc to draw on the 2000 mah battery that drives the rudder, elevator, and spoilers. What is the advantage of this 270 mah nimh battery and why carry the extra weight?


http://www.djaerotech.com/dj_product/chrysalis2m-e.html

ransom peek
01-07-2007, 06:55 PM
http://radicalrc.secure-mall.com/shop/images/17.jpg Radical RC 370mah NiMH 4-2/3 AAA Cell 4.8V Square RX Pack

2/3 AAA RRC-NIMH. 4.8V Square RX pack. This size not available in Sanyo brand. VERY popular 1/2 A, HLG pack, Combat and other weight and size critical applicatons. This cell is great in E-flight and has proven to be a great Reciever pack as well. LESS weight than 110 Nicad!!!! Weight 29.8g/1.05 oz.

SKU Number:RRC04H0370S Price: $9.00

How can it be that for the same #cells and capacity, nimh batteries can have different weights?

Jason T
01-08-2007, 10:01 PM
The Radical RC 370 pack should work fine. Just remember to charge it frequently. I am using a few receiver packs built out of GP400 cells. I use them in my handlaunch and my F5B sailplane. The rx pack in my sailplane drivers 5 HS125MG servos and I will usually fly it about 2-3 flights before recharging it. Typically I put back about 100mah. However, this will differ depending on how long each flight it is so fly with it maybe charge after the first flight to see how much you put back in and charge as necessary.

I use a 4 cell 700mah pack on my thermal glider since I since it is intended for longer flights. That pack drives 6 Dymond D-60 9 gram servos with ease.

Regarding your question about the different weights in similar capacity and size cells, this is not uncommon.

ransom peek
01-09-2007, 03:50 PM
The instructions for the DJ Aerotech 2 Meter Electric Chrysalis call for 270 mah nimh receeiver battery, so I am thinking anything more will add undesirable weight and loss of porper palne balance, and from your comments am guessing that perhaps 270 mah is enough to never be the limiter on any flight.

The power system uses a 2000 mah battery and it will drive the motor 5 or 6 times pulling the glider up to altitude for sailplane flying.

So, I will search a bit more for the 270 mah nimh 4.8v receiver battery. Still cant find them anywhere!

Jason T
01-09-2007, 05:34 PM
I normally order my receiver pack battery cells from http://www.cheapbatterypacks.com. (http://www.cheapbatterypacks.com/)
If you go this site you and click on the loose cells button on the upper left it will display several different cells types. For receiver packs you could use the KAN 350's or KAN 400's since their are the same weight and a 4 cell pack like you want to use would come to a weight of about 1.08oz. This would give you plenty of flight time for basically the same weight as the 270 back. I do not think the receiver pack weight is going to make any noticable difference in the glider performance since according to the specs that the flight weight is going to be a minimum of about 37 oz.

Also, if you are not comfortable building your own battery packs, Cheapbatterypacks.com will build custom packs. I went through the custom packs link and built this pack with 4 cells of KAN 400's, brick configuration, 20 ga wire and the Hitec male servo connector and the built price was $8.

ransom peek
01-09-2007, 08:52 PM
I found these 2 choices for single cells at Cheapbatterypacks http://www.cheapbatterypacks.com/main.asp?sid=681099&pgid=loosecells
to build yourself. The second one below seems best at higher mah but same weight.


CELL SPECIFICATIONS

2/3AAAChemistry:

NIMHCapacity:350mahLength: 1.13in.28.70mmDiameter:

0.39in.9.91mmWeight:

0.27oz.7.65gm

CELL SPECIFICATIONS

2/3AAAChemistry:

NIMHCapacity:400mahLength: 1.13in.28.70mmDiameter:

0.39in.9.91mmWeight:

0.27oz.7.65gm

Radical RC pack at 370 mah and 1.05 oz (vs 0.27 oz x 4 + unknown weight of pack hardware) is similar weight (I think) but lower capacity.