The one I am currently using is a older pack from remote helicopter. Brand is Turnigy 5000mAH, cost about $40 each and if u get the 4S u can briefly charge it with car, but alot safer to do it with a $60 Lipo charger with balancing cables. These are the thing this pack have started up.
Diesel hilux, 140HP Suzuki. 25HP Yamaha, V6 AMAROK, 200 series cruiser. And a 75HP Kubota tractor.
There is a trick to setting it up. The plug on the pack they come wigh have to be remove and replace with 50A anderson plug and another plug with minimum 6mm with short as possible cable connected to battery. There is possibly better way to set it up. Someone will comment soon. But this works fine for me.
Always remember to disconnect as soon as your motor starts up