Model Boat Mayhem

Dry Dock / Shipyard: Builds & Questions => Yachts and Sail => Topic started by: lulu510 on January 16, 2012, 06:42:30 PM

Title: Lipo batteries and Yachts
Post by: lulu510 on January 16, 2012, 06:42:30 PM
Hi I am a newbie to RC yachts moving from Helicopters and fixed wing planes where I have been using Li-po bateries. I am just about to build a  Thunder Tiger Victoria and was wondering if I could use a 2s lipo (7.4V) instead of the Nicad that are recommended. I believe it will give longer sailing times. Any advice apreciated.
Lulu510
Title: Re: Lipo batteries and Yachts
Post by: CF-FZG on January 16, 2012, 07:09:09 PM
Yes, there's no problem as long as you use a regulator to reduce the voltage to between 5 and 6 volts :-))


Mark.
Title: Re: Lipo batteries and Yachts
Post by: Subculture on January 16, 2012, 07:33:08 PM
I'd fit some sort of flashing or buzzing gizmo to alert me if the cells were getting too low.
Title: Re: Lipo batteries and Yachts
Post by: john s 2 on January 16, 2012, 07:39:29 PM
Battery capacity is what dictates running time. This is measured in milliamps. If your sailing a Yacht then current drain will be low. As the motor is power hungry. which of course youve not got.  As youre familiar with lipos then use them. If they are out a plane then im not sure what size they may be. Im sure someone else can advise you better on this.John. 
Title: Re: Lipo batteries and Yachts
Post by: Tombsy on January 16, 2012, 08:40:37 PM
You could try a LiFe pack (A123) , no voltage limiter needed and they last and last, I've switched all my nitro boats from lipo to LiFe.
Title: Re: Lipo batteries and Yachts
Post by: Netleyned on January 16, 2012, 09:01:24 PM
A 5 stick NiMH hump pack 2600 mAh lasts over three hours in my Victoria
No problem charging them and not likely to run them to destruction.
Why bother with LiPo's?

Ned
Title: Re: Lipo batteries and Yachts
Post by: Tombsy on January 16, 2012, 09:37:05 PM
For me, the LiFe cells are lighter, the voltage stays stable even under heavy loads vs the nimh's fairly linear drop off, you can charge the LiFe faster, and they hold their charge for months not days like nimh.
Title: Re: Lipo batteries and Yachts
Post by: Kangaroo1 on January 16, 2012, 09:53:02 PM
Like Ned, I too have NIMH's fitted in my Victoria, albeit only a 4 pack, and these are perfectly adequate for me.
Title: Re: Lipo batteries and Yachts
Post by: CF-FZG on January 16, 2012, 10:56:03 PM
Guys, all he asked was if he could use his (existing) 2S LiPo packs in his yacht.

Can we just answer his question without getting into a (potentially) argumentative discussion over whose batteries are best >:-o


Mark.
Title: Re: Lipo batteries and Yachts
Post by: lulu510 on January 18, 2012, 06:09:54 PM
Many thanks folks. :-) having weighed an 850 2s lipo and a 6v BEC  against 4AA batteries without a holder it is half the weight so I think I will stick with the Lipos. Once again thanks
Lulu510
Title: Re: Lipo batteries and Yachts
Post by: Tombsy on January 19, 2012, 12:31:56 AM
I just came across these at Overlander, a hybrid nimh that holds its charge for a year?
http://www.overlander.co.uk/hybrid-rechargeable-battery-2100mah-4-8v-flat-rx-enerpro.html (http://www.overlander.co.uk/hybrid-rechargeable-battery-2100mah-4-8v-flat-rx-enerpro.html)
Anyone familiar with them?
Title: Re: Lipo batteries and Yachts
Post by: Boomer on January 20, 2012, 04:38:16 PM
Just a thought - what ever the source of power - 6 volts would be worth considertation. Generally, servos are rated at both 4.8 volts and 6 volts. The servo is able to achieve it's full potential or maximum torque rating with the 6 volts power source.  In a smaller boat like a Victoria, it might not be as critical as in a larger boat carrying more sail area.

I run 6 volts in all my boats for that reason. I like having the power there when I need it. When selecting sail servos, while I don't disregard the 4.8 volt rating, I am more interested in the 6 volt rating. Using rechargeables is certainly the more "green" way to go, but honestly using four 1.5 volt AA batteries I can operate a 1 Meter yacht for hours upon hours with no issues.

It is really a personal choice - but 6 volts is my choice. :-))
Windchaser
Title: Re: Lipo batteries and Yachts
Post by: Tombsy on January 20, 2012, 06:00:08 PM
There seem to be more high powered servo's coming out that you could use without a regulator with lipos or LiFe.
I just got a few of the new waterproof Hitecs to try and they are rated for 6 and 7.4 volts.
Title: Re: Lipo batteries and Yachts
Post by: sunworksco on March 05, 2012, 08:02:37 AM
I'm using servos that can handle up to 9 volts and a custom built Probar style geared winch arm system that can handle up to 12 volts.
Lipos are a good choice. I use lipos and LiFe batteries with excellent results.
Kind regards,
Giovanni