Lead Acid Battery Question

[CKoz]

Good morning,

I would like to ask you'all your opinion on running a boat with a lead acid battery. I recently scored an old 4 foot long Dumas PT boat. I love it.

I installed a really nice Turnigy T600 1100kv outrunner along with a 180A ESC. I tested the boat successfully with a 5000mah 2S 7.4v battery. It lasted almost 40 minutes. Both the motor and ESC are watercooled and were cool as ice once done. T600 has a max spec'ed current of 100A.

Speed was adequate, but of course we all want more....

My question is would it be at all possible to run this motor with a 12V 6AH lead acid battery? The boat has plenty of room for this.

Are there any downsides to doing something like this?

I'd love to know what you think.


Thanks in advance...

Chris

[TRUCKPULL]

Hello Chris

Most Lead Acid sealed batteries in the 6 to 7 AH rating weigh about 4 pounds
The extra weight may up your Amp draw a bit.
Also they are NOT rated for the 100Amp that your motor is, ( most are only rated for about 50Amp max for 30 Seconds)

To get a sealed battery that will give you some AMP's you would have to look at a 12V Marine deep cycle battery for an electric trolling motor. (15 LB)

Larry

[Peter A]

You could use the 12v battery, it is a lot heavier obviously, but it will work. Alternatively you could just use a 3S 5000 mah battery. It will be faster but at the expense of some runtime. But even 1/2 hr is still a pretty long run around. At the end of the day try it, run a bit, check things, run some more. By your runtime you are only drawing around 6-7 amps current average.

[CKoz]

Thank you both. I do have one of those in line monitors that logs actual amp draw and such. Maybe I'll test with that first to see.

Much appreciated.

Chris

[rol243]

try using some 3s lipos in parallel , eg; 2 or 3 x 3s -4000 mah - 60c. lighter than a lead acid battery and should give you a good run time.

[Bp9145]

if you have lots of room you can increase the capacity(mah). As rol243 mentioned running two 3S 4000mah will give you 8000mah and will certainly give you plenty of runtime and is definitely much lighter that a 4lbs lead acid battery. Furthermore, if you still want more run time you can increase the capacity to greater than 4000, like maybe 5500mah and if you run two in parallel you'l get 11000mah. . .just remember you have to get two identical batteries. Good luck and enjoy your new boat

[CraigP]

Lead acid batteries are not linked inside for this high of continuous current draw. You will probably burn it up inside... So I would say it’s not a good idea... This is especially true for a sealed type like AGM.

[Hydrocarbon82]

Do you have a 2nd 2S battery? That motor is rated up to 7S and the ESC likely is good to 6S, so it shouldn't be an issue running it on 4S. If it's all ice-cold than chances are the prop is undersized for the 2S config and okay for 3S or 4S. If not, then keeping 4S throttle at 75% wouldn't need any smaller prop than 12V use.