XRAY - Model racing cars

Hi All,

Would like you to give your opinions and feedback on how much effect in terms of balance and performance of the car using different types of batteries with different weight. (NiMh, LiPo and LiFe)

Much appreciated!

Thanks

NiCad:
2/3A cells, currently up to 700mAh to find but not interesting due the capacity.
Can be charged up to 3C

NiMha:
Also in 2/3A cells, currently up to 1700mAh to find and have done the job for years and is currently still a good choice.
Can be charged up to 2C

LiPo:
Can be found up to 2200mAh but needs a voltage regulator. A good switching regulator does lower the current at the battery which makes is look like you can drive a lot longer for sure with the higher capacity.
The regulator gives a steady 6 or 6.2v voltage which (regarding the drivers) does provide a faster and stronger servo. The regulator is also a source of errors if not choosen the right one.
A regulator is not needed when using a receiver with an own internal regulator (most 2.4GHz receivers) and HighVoltage servo's
It is the only real light weight battery.
Must be charged with 1C and some newer models 2C

LiFe,
6.6v seems to be safe for most electronics without a regulator. Currently to find up to 1450mAh. The higher voltage does give faster and stronger servo's.
Not sure but I believe they can be charged up to 5C (larger cells can)

Hi Roelof, for NiMha when you sais charged up to 2C you means up to 3400mAh. But this for all type and brand of these battery ?

thanks a lot

2C = 2x capacity and I did say UP to....

So yes, a max of 3400mA could be done with 1700mAh cells. I would not realy advice it because you see some performance difference after a few charges (huge startpeak and a low 2nd half) but if you have short time it can be done. I have VTEC 1600mA cells and I charge them with 2.2A and that goes fast enough in between the finals and the voltage is constant from the beginning to the end.

If u r using LiFe battery do u need ''XRAY Brass Battery Plate For Lipo Batteries 336156'' ? can i use ''336170 Brass Chassis Weight for NT1 30g'' instead of the lipo battery plate ?

Nihm = 130-140g
Lipo = 85-90g
Life = 75-80g


Lipos are definitely heavier than LiFe.

I'd strongly suggest running LiFe. No regulator, it doesn't create the "memory effect" like Nihm and Lipos.

I would strongly advise getting the Brass Battery Tray. Its about 55g in the lowest point in the car.

I wouldn't substitute the 30g weight for the Brass battery tray, but thats just me. The Xray NT1 is so lightweight from stock, that I would use both at the same time.


Only reason I would go Lipo route is to use a low-profile lipo in order to lower the tank 3-4mm.

If your running Spektrum (brand) receivers, they have regulators integrated, but I have heard some people complain that the drain on their battery is much higher without and exterior regulator.

Hope this helps.

I usually just balance charge it at home the night before.

Then re-charge it before the mains without balancing it.


I ain't using the receiver box. I just have my receiver taped to the throttle servo. The wire from my battery is long enough to run through the back of the throttle servo and into the receiver. No extensions and no hassle. I do use a tie-wrap to hold the cable in place just to make sure it doesnt touch the ground.

Hope this helps.

Hi

in case you go for the LiPo or LiFe batteries it will be a good idea to use the optional brass plate for the batteries. Think that these kind of batteries weight less than the NiMH and you are eliminating weight from the bottom part of the chasis where it´s more interesting to have weight to lower the CG.

Apart from this I don´t particularly like LiPo since you have to use the regulator and this is one more electronic device that might suffer some kind of problems. Keep your electronics as simple as possible.

Cheers