You didn't say if the Slash 4x4 was the brushed or brushless version. If it is the brushed system then that would be a very good battery. However if the slash is the brushless version, I would suggest you look at a battery that has a C rating of 30C+ due to the amp draw of a brushless system.

You most likely will end up stressing a 20C Lipo with a brushless system and it may not deliver the punch you would expect.

Anything 11.1 Volt, 5000mAh or more and 30C or more would be a great battery for the slash 4x4 brushless.


Just my -98cents worth, Hope it helps.