I use a 4s lipo/5000 mah/50c on a dynatron to start my boats. Lasts just fine for a race weekend. Fri. test & tune, then 2 days with 3-5 boats @ 4 heats each = 15 to 25 starts. Battery is attached to the starter with Velcro & straps. Added a Sullivan handle, compact & light set up. Works great even on HIGH compression 2 stroke gas race engines. Since there is no ESC with a low voltage cutoff, I use a volt monitor that plugs into the balance lead.