Model Boat Mayhem

Mess Deck: General Section => Model Boating => Topic started by: tt1 on February 14, 2010, 01:59:43 pm

Title: Battery size for lighting
Post by: tt1 on February 14, 2010, 01:59:43 pm

Hi all, I'm currently building my first model - a loyal class from Model Slipway, and would like to power up 30 x 6 volt grain of wheat bulbs all at the same time ( %%) I have fitted one to every lamp possible including 4 in the wheelhouse. I know there are correct lighting sequences for varying conditions etc. but it's my first dabble and am having fun, they won't be a true representation in real terms, but they might look pretty! {-) I'd like to use a "boxy" shape sealed lead acid battery dedicated to the lights and help towards ballast.
   
Can anyone recommend the size of battery (power / amp hrs) needed for a number of 10-15 minute durations without having to constantly recharge,  and also how much juice the lights will pull.
       I've heard these bulbs don't last too long before burning out, but I'm too far down this road to change now.

             Cheers, Tony.

Title: Re: Battery size for lighting
Post by: Shipmate60 on February 14, 2010, 02:08:16 pm

Tony,
The only spec I can find right now is 60 ma per bulb so 30 are about 1.8 amps so for about 1/4 hr would need 0.45 Amp Battery.

Bob

Title: Re: Battery size for lighting
Post by: FullLeatherJacket on February 14, 2010, 02:24:46 pm

Tony
There's plenty of room inside that big hull for a reasonably-sized battery. Component Shop list a 12v 3.3AH gel cell for a tenner. The 5AH one isn't much more.
FLJ

Title: Re: Battery size for lighting
Post by: DickyD on February 14, 2010, 02:50:37 pm

Quote from: FullLeatherJacket on February 14, 2010, 02:24:46 pm

Tony
There's plenty of room inside that big hull for a reasonably-sized battery. Component Shop list a 12v 3.3AH gel cell for a tenner. The 5AH one isn't much more.
FLJ

Ignorant me again Dave, 12V battery for 6V bulbs ? {:-{

Title: Re: Battery size for lighting
Post by: FullLeatherJacket on February 14, 2010, 03:14:47 pm

Sorry - we all miss things sometimes! I'll let you look up the equivalent 6v battery, Richard - I've got 50 x P100s to build.
FLJ

Title: Re: Battery size for lighting
Post by: DickyD on February 14, 2010, 04:07:11 pm

6Volt 5amp £5.75 each plus cheap postage. Last one I had, £2.00 postage.

http://www.component-shop.co.uk/html/body_lead-acid.html

Title: Re: Battery size for lighting
Post by: tt1 on February 14, 2010, 05:29:34 pm

Thanks to you all for your responses, excellent info - just what the doctor ordered!

                                         Ain't half glad I joined this forum!
       Regards, Tony.

Title: Re: Battery size for lighting
Post by: knoby on February 14, 2010, 08:24:07 pm

Hi tony, to improve the life of the bulbs you might consider dropping the voltage to  around 5 volts. You can use a resistor ( around 2 ohms 5 watt) or even a 5 volt bec to achieve this. Using 5 volts wont affect the brightness to much.
cheers Glenn

Title: Re: Battery size for lighting
Post by: tt1 on February 14, 2010, 09:55:43 pm

Thanks for your input Glenn, would certainly consider carrying out your suggestion, but (you may not of noticed my previous postings) when it comes to r/c / electronics I'm a lot dimmer than the bulbs would be! LOL. I'm getting there slowly and this forum is a boon, but it has to be a step by step guide in layman terms I'm afraid.
So--------------- if you could expand a little more I'd be grateful. Would the resistor be wired on the + side of the battery feed?

Thanks again, Tony.

Title: Re: Battery size for lighting
Post by: knoby on February 14, 2010, 10:39:49 pm

Hi tony. yes in the + feed to the lights would be fine. If it was me i would experiment with the resistor size to get the best effect, trying different values between 1 & 3 ohms. There are other ways of lowering the voltage, but most require some simple electronics knowledge, resisters would be the easiest way.

hope this helps
cheers Glenn