Battery size help

[Queequeg QuintParticipant @queequegquint38270]

My boat is about 35 inches long, 11 inches wide, Novi lobster boat hull.  Motor is MFA Como 800, direct driving a 55mm 4-blade brass prop.  I’ve run her hooked up to a 12-volt battery and she ran great for a long time.  But….

 

The battery I’m using is 10AH, therefore it weighs about 10lbs.  Way too heavy for my boat.  Before I start buying other batteries, what do you guys reccommend for a battery.  I really want a looooonnnnnngggggg run-time so that’s why I opted for 10AH, but it’s just too heavy.

 

Your thoughts?

[Queequeg QuintParticipant @queequegquint38270]

[Dave MilbournParticipant @davemilbourn48782]

A 12v 10AH gel cell weights around 3 kg. A 10-cell D-Size NiMH 9AH pack weighs 2.1Kg. Price is £72.50. Two 12v 4600maH Sub-C packs would cost about the same but weigh only about 1.3Kg together. A 3C LiPo pack (11.1v) weighs only 350g, but it only holds 4AH. It also costs £54. All prices and weights c/o Component Shop’s website.

I would think about changing the motor for a smaller, lower-current one running through a belt-drive or gearbox. That way you’ll be able to use a smaller SLA battery and still have the same running time.

DM

[ashley needhamParticipant @ashleyneedham69188]

Q.  Depends how much weight you need to lose!

 

I would just change it to a 7Ahr 12v gel battery as easiest method, personally.

 

Should run for a fair old while (lasts ok on the Seahawk with a single 850).

 

HOWEVER, if thats not enough weight saving you will have to go NiMh, as suggested.

 

Do you have any other ballast barring the battery?

Ashley

[Author]

Posts