Are 2 smaller batteries better than one bigger

[paynpakbldr]

I have a question ... if i used two 7.2v 3000mAh NiMh batteries would the mAh add up to 6000mAh thus improving my run time or would that not work. and would using one 7.2v 4500mAh be almost, same, or better than the above before mentioned setup. i will be using the batteries for a graupner mini jet drive with 500 speed motor. Or does anybody have a recommended battery for this?

[Kmot]

Two equal batteries, of any size, connected in parallel will double the mAh capacity.

A single 4500 battery will give you 75% of the capacity of the two 3000's connected together in parallel. However, the single battery will weigh half as much as the dual batteries and so the less work required to move the boat may negate the difference in mAh capacity.

[waboats]

Kmot says it fairly clearly.

Depends really on what boat you are running.

I use twin 4.8v packs (9.6v) to run the mini jet on the Graupner Jet Sprint through a 600BB and it runs nice. A fairly small boat all round... Less power (Volts) & it doesn't get up on the plane. 2400Mah gives about 15 minutes runtime.

What Boat are you building ???

[Prins Willem]

It depends if you are running a displacement (tug, freighter) or planing hull (speed boat, patrol boat). With a displacement hull most everyone on this forum will say use batteries for ballast instead of dead weight. The other positive for this is being able to shift the batteries around to trim the model.

Weight is a killer in a planing hull so one high capacity battery would be preferable. In fast electrics using two NiCad or NiMh packs they usually wire them in series to up the voltage.

[paynpakbldr]

Kmot says it fairly clearly.

Depends really on what boat you are running.

I use twin 4.8v packs (9.6v) to run the mini jet on the Graupner Jet Sprint through a 600BB and it runs nice. A fairly small boat all round... Less power (Volts) & it doesn't get up on the plane. 2400Mah gives about 15 minutes runtime.

What Boat are you building ???

I have scratch built my own fiberglass hull... and am using some old electronics i found laying around in it(Futaba magnum Jr. and old reciever and servo with the old "G" connectors)

[paynpakbldr]

Thanks for the help everybody... i think i am going to go with one high mAh battery pack