One of my batteries went bad so I want to buy one or two new ones, but wanted to get the best one for my set-up. I have read about the differences between "25C", "30C"....etc. and still am not sure which way to go.

My 3 battery options (all are 2s lipo)

1) ProTek R/C 2S "Supreme Power" Li-Poly 50C Hard Case Battery Pack (7.4V/5600mAh) (ROAR Approved)

2) ProTek R/C 2S "Supreme Power" Li-Poly 40C Hard Case Battery Pack (7.4V/5000mAh) (ROAR Approved)

3) ProTek R/C 2S "Supreme Power" Li-Poly 30C Hard Case Battery Pack (7.4V/3800mAh) (ROAR Approved)

I am going with ProTek because their batteries are great and I want to support Amain since they are down the road from my house

Here are my 3 set-ups. I want the perfect battery for the given set-up

1) Slash 4x4 with Velineon 3500kv brushless motor (stock)

2) Team Associated T4 stadium truck with Sidewinder ESC with 4600kv motor

3) Team Associated T4 stadium truck with Tekin RS ESC with 17.5T express duo2 motor

Any help would be great. I don't want to throw down $$$$ then wish I had gone a different way. Thanks in advance.

I wouldn't buy the 3800 stricltly due to the reduced capacity (mah) - shorter run time. That may not be an issue if you're racing and the heats/races are short.

I have a 2wd Slash and have been running Sidewinder/5700 combo with a 2S 5000mah 30C lipo and there is no shortage in power. I'm changing to a 3500 Velineon cause there's too much power with the 5700.

I'd buy the lipo listed in the middle, the 40C 5000mah. I doubt you'll see any diff with the 50C and the diff in capacity is small.

Thanks for the reply. I was leaning towards that as well. Anyone else have thoughts on either the T4 or slash 4wd battery selection??

I'll second that.^ go with the 5000 40c.