batts for bcx2

[spankone]

i've seen a few other brands doing batteries for the blade cx2 any ideas which is the best/ for the money

[Snarf]

Don't know if they will fit the Blade but I bought 3 2S 12C LiPos for my Twister Medevac. They are 28x53x14 mm (the exact same size as the stock JP batteries) but are 900 mAh instead of 800.

They where £2.99 each BUT postage was £11.36 (so I bought 3 to bring the unit cost down to about £7.00)

The new batteries perform a lot better than the stock (1) they last longer, (2) they hardly get warm and (3) they seem to be able to deliver more power before the voltage drops.

I charge them on my cellpro charger and can confirm the higher capacity.

I got them from "cwtco" in Hong Kong via fleabay and they arrived 4 days after I placed my order.

[Sieze2]

i've seen a few other brands doing batteries for the blade cx2 any ideas which is the best/ for the money

I really rate the DN power 850 mah 15 C batteries, Infact I even wrote a review on another forum. That said I see my supplier has now changed to mega power who also do a 15 C version. I know they have had a bad history with puffing, but mine have been very good, and I have done about 50 cycles on them :


I couldn't find a review of any 15C batteries for my blade Cx2 so thought I would do my own;

Initially I was torn between a 900mah battery and the 850 Mah 15 C one. To say I am pleased with the 15 C one would be an understatement. The performance advantage of the 15C battery over the standard eflite li-po's is massive. The best way to explain what they are like, is to compare them to a fully charged standard battery in the first 60 seconds of use. If you give it full throttle the heli shoots up like a rocket. Well the 15C batteries are like that through the whole filght. There is only a marginal decrease in performance after 8 mins or so. When I fly with the standard batteries it is common for me to not be able to pull out of a rapid descent, and to bounce off the ground. Simply because I was expecting more lift on full throttle.

I would argue the point that the motors are more than able of awesome performace, but that the standard batteries can't deliver enough current to satisfy them. I believe the standard batteries are rated at 10 C which means the DN power ones can deliver 50% more current. Additionally they don't seem to get hot after a flight like the standard ones.

I know people have argued the merrits of the extreme motors, but I had no idea a bettery replacement would have such an effect on the full throttle performance of the heli !

[Bubblefish777]

So what batteries did you end up buying...who from and at what price ? I might give them a whirl

Cheers.

[spankone]

i bought any yet i have to many hobbies and cant spend money on the all at once

so 15c refers to current and mah is power right?

[Snarf]

mAh is the capacity (i.e. a 900 mAh battery will provide 900 milliamps for one hour at the rated voltage - 7.4 volts for a 2S pack - 2 cells in series).

The C rating is the RATE at which the pack will deliver current. 1C is the 1 hour rate (i.e. 900 milliamps for a 900mAh pack) and this is the normal charging rate for a LiPo so they take about an hour to charge. 15C means that the pack is capable of providing 15 times the one hour current (i.e. 15x900=13500 milliamps or 13.5 amps for a 900 mAh 15C pack). Of course, it can't do this for an hour and would, in fact, be exhausted in less than 1/15 hours at 13.5 amps (in practise our motors should not be drawing this current continuously but, on the other hand, we aim never to fully discharge the packs so the duration calculation is very rough).

At 13.5 amps and 7.4 volts we have a power of 13.5 x 7.4 = 99.9 watts (i.e. a bright domestic lightbulb).

All this is at steady state of course. If you REALLY want to know when and where all the juice is going, you need to install a logging power meter but I leave that to the people who do the serious pack reviews.

[Sieze2]

So what batteries did you end up buying...who from and at what price ? I might give them a whirl

Cheers.

I got mine from KrS hobbies. They only seem to stock the mega power ones now though? They are $15

http://www.xtremecx2.com/servlet/the...-CX2%2C/Detail

Boomtown sell the Dn's http://shop.boomtownhobbies.com/cate...c?categoryId=6 They are $20.

[Bubblefish777]

Ok so humour me here for a bit......

There's 2 batteries .... identical in 850mAh and 15c rated ..... yet one is $19.90 and £19.95.....what's the differece apart from 5cents... ? (This is from Boomtown) also I then see another CX2 battery.... rated 900mah rated at 10c ?????? said would give an increase of 10% flying time (since when was 10% of 850 = 50 ????) Anyway..... am I looking for a high 'C' factor (I interpret this as ability to meet demand efficiently) to ensure consistancy for my heli in flight ? i.e. a 10c compared to say a 20c .... if you stress the engine you'll find performance decreasing as the 10c struggles to meet demand ? and what's the "puffing" effect as described on the cx2extreme website ?

[spankone]

good reply guys keep it up

and yeh whats puffing?

[Sieze2]

good reply guys keep it up

and yeh whats puffing?

If you overdischarge or even discharge too fast, or just have a defective pack, the cells can puff up. If you subsequently try and charge the battery, it can pop/catch on fire.

I would only reccomend a 15C battery for the blade cx2. It gives loads more power than the standard battery. Simply put the standard 10C battery can't deliver enough current to satisfy the motors. By putting in a 15C battery, it has the same effect as more powerfull motors. You won't be dissapointed