What battery should i use

[stormlauncher]

Can anyone tell me what battery i should use to power a 900s motor?

[pompebled]

Can anyone tell me what battery i should use to power a 900s motor?

In what size / type of boat?
What's the speed/runtime desired?

Is a 900s a brushed one (link?).

Regards, Jan.

[stormlauncher]

hi yeah it is a jeti interceptor its about 30" inches long i am not sure about the speed or runtime!.It is not a brushless motor.

[pompebled]

Now I'm confused...

- I'm familiar with the Intercepter 650, which is 25,5" long,
- Jeti is a brand of ESC, or the name of a big hairy creature living up North,
- A 900 series motor is way to much (in weight and cellcount) for an Intercepter 650, a 600 series motor would fit quite nicely, are you sure you didn't turn a digit upside down (9/6)?
- Google came up empty with "jeti interceptor". (got a link?)

I'm willing to help, but need to know what it's all about.

Regards, Jan.

[stormlauncher]

Hi am not sure what series it is as i bought it off ebay it is 28" long it is called a interceptor ultra they said it had a 900s motor in it,is there a way of checking this?
Thanks for your time.
Ian.

[crvogt]

Ian,

In general the size of the motor is approx. the can length in mm x10. A 550motor is about 55mm can length,, Which is probably what you have in a 28" boat...
look at what the battery connector looks like. Is it a white Tamiya type connector?

I have two boats in that size catagory and they use a 6cell sub-C battery pack

They use a pack like this http://cgi.ebay.com/Two-7-2V-3300mAh-NiMH-Battery-Packs-for-RC-Car-E-Maxx_W0QQitemZ330053680232QQihZ014QQcategoryZ34063 QQtcZphotoQQcmdZViewItem
check the dimensions and see it it fits the battery compartment.

Hope this helps
Carl

[stormlauncher]

Hi,
yes you were right the motor size is 55mm i appreciate your help thankyou.
Ian.

[retoabcr]

First the motor would be the Traxxas 12t at 22,000rpm, approx, next a 435 prop and 7 very good cells. Now a boat at 25" should use a good 550 motor and as a Grauper 600-7.2 is rated at 21,000rpm on 7 very good cells. You could use a Monster maxx wild (550) but rpm is not up there enough for speed unless a big prop is used which incase runtime will suffer greatly!

[pompebled]

Ian, could you show us a picture of your boat, shot from the rear?

The reason I ask, is that the Intercepter 650 has a tunnel around/above the prop to protect it.
This tunnel severely limits the size of the props that can be used, and thus the motor and battery choice.

If your Ultra is the same design, I can make some suggestions about what to use.

Regards, Jan.