Nice catch Dave my error thanks!!!

HI laurence
Haverlock made a slight error in his calculations, the battery is 2.2 amps which is 0.275 hours or about 16 mins.
I would expect you will get about 10 mins from my experience of similar models and set ups.
Duration will depend on how you sail the model, bit like a car really, if you are heavy on the throttle you use more juice!
Speed should be good for about 2mins after which the battery voltage will start to drop, current will increase and the speed will be markedly less.
Ideally you need to know the current being drawn in the water, a high value ampmeter is required. There are meters that you can buy (Wattmeter) - - that will give you amps, watts and voltage. Your battery supplier may be able to help, but they are available online. http://www.brchobbies.co.uk/catalog/index.php?cPath=121&osCsid=2adae23f247a1070e6def01915477cad.
Hope you had a good Christmas, no doubt you are now preparing for New Years Eve.
Dave 😀

12v so ok there

2200mAh that's fine.

Duration ( takes a deep breath) it depends upon your prop and how free your shaft etc. is.

Max efficiency is at 8A so 22/8= 2.75 hours.

HOWEVER your not going to get that!!!

You lose some current to the esc. and if you have a bec. to your receiver and steering servo.

Added to this is the fact that the battery voltage will fall so speed will reduce.

figure 30 min to 1 hour.

Hello again everyone, I've looked and found a 12v 2200mAh battery pack. in your opinion would this work well with a 900 motor? Also do you have any idea what sort of run time I would get?

HI Haverlock
The weight will be carried by the water but the motor will still have to move this weight. The Sea Queen goes well on the plane but this does require speed and power as well as having the balance in the correct place. A large SLA is restricted as to placement so will affect the speed obtainable.

Designed for IC power plants the model adapts well to modern electric power, which is, I believe, Laurence's preferred choice.

Seasons Greetings to you
Dave

Sorry Dave but your post got me thinking, ( always a worrying situation).

Since the weight of the boat is carried by the water it weighs nothing. This being the case the weight of the battery has no effect on top speed!!!!

What it will effect is inertia a heavy boat will accelerate more slowly than a light one. ( this presumes identical hull motor prop etc.)

Provided care is taken a motor bike 12v accumulator could be used this reduces difficulties of supply and a cheap charger.

As I remember the sea queen is a big old beast and I remember seeing at least one with a taplin twin 15cc engine fitted.
I suspect you could use a "weed wacker" motor and not overpower the hull.

Please feel free to correct me ( flame me) and generally pick holes in my post Dave.

Merry whatever you enjoy!!!!!

HI Laurence
As Haverlock says the answer is no.
A quick check on the stats for the Graupner speed 900 gives
Speed 900 BB TORQUE 12v 6-40v
revs 6,500
Free running 1.1A
Max efficiency 8A
Stalled 54A
Efficiency 71%
Size 95mm 51.5mm 15mm 6mm 645g.
You will need a high power NiMh of 12v or a SLA. You could run on 6v but performance will be more like a canal boat.
You can expect a current draw of between 10-20 amps depending on the prop and speed.
The SLA will be heavy so performance will not be good. A NiMh will perform better but will not be cheap.
Are you considering this for your recently acquired original Aerokits Sea Queen?
I see from your profile you are in a remote location so carriage costs will feature in your decisions and NiMh may be the cheapest option compared to a SLA.
Hope you can find a suitable power set up
Dave

You can use a dry cell battery BUT you will be sadly disappointed by the results.

it would also prove to be expensive.

Rechargeable batteries are more expensive to buy BUT work out much cheaper in the long run even when you count in the cost of a recharger.

Also dry batteries cannot supply the same current all dry batteries use a chemical reaction to provide current and trying to draw to heavy a current will cause them to "gas up" reducing the amount of current they can supply.

A speed 900 is enough of a motor to move your sea queen around you need an ESC to control speed and direction (of the motor) the motor will be at its best running on 12 volts so consider a lead acid accumulator

http://www.cornwallmodelboats.co.uk/acatalog/lead_acid_batteries.html

some examples.

Thanks Dave for your reply, I bought a Sea Queen model kit last year and built it but wasn't happy to be prepaired to put in the water. I had problems with the prop shaft and the keel of the boat. I'm not sure if the kit I got had been water damaged but after I fitted the hull skins the boat was about 5mm longer than it should have been, reason being the keel wasn't true. Had I have known I would have strapped the keel and bow to compress the difference.
Anyway, I have a 900 speed motor that came with that kitt, if I ran it on a 6volt dry cell battery would it work in your opinion?

HI Laurence
Brushless will give you much greater power but will require a brushless ESC.
Lipo batteries are very efficient and will give you much greater power to weight ratio than other batteries. On the down side they need to be treated with respect in regard to charging and the minimum discharge voltage. Exceeding these set parameters will damage (irreversibly) the battery and in the worst case can result in the battery self destructing. Providing you follow the manufacturer's guidelines and use a good balanced charger and an ESC with a cutoff mechanism the risks are minimal.
I do not know how knowledgeable you are with your modelling so apologise if I am teaching you to suck eggs!
You do not have to use Lipos as NiMh will work, just not as fast.
I used a 42-38 750Kv outrunner motor purchased from Giant Shark, sadly no longer trading. Outrunners are generally more suited to model boats but you can use inrunners which are in a can similar to a brushed motor.There are many suppliers on line and the 42 related to the motor diameter and 38 is its length. The 750 relates to revs per volt so on 10v it would be 7,500 revs free running. I would avoid any motors above 1300KV as they will make your model too fast.
My motor draws about 30 amps at full speed with a Prop Shop 40 (Sorry can't remember exactly, ask Simon and give him model and motor details). I use an 80 amp ESC that is forward only. I added my owm water cooling as well as making a watercooled block for the motor. You can buy ESC for boats with fwd/rev and water cooled as well as water cooled mounts for the motor.
There are three wires between the motor and ESC and reversing any two of the connections will reverse the motor's rotation. Some Chinese will claim there ESCs are reversible because of this, so be careful to check that direction control is from the transmitter.
Please ask if you require any further help or info
Good luck with the restoration 😀

Dave

HI Dave, I'd quite like to try fitting a brushless set up in it but I've never worked with brushless or lipos before. Any recommendations would be welcome.

HI Laurence
Nice clean looking original Aerokits model.
If it's as clean inside you wont have too much work. My Sea Queen needed all the old paint removing and renovation inside as an IC had been fitted. Needed to replace the shaft as the original was too badly worn. Took a while to remove all the old gunge inside but fortunately the hull had been sealed so the wood was not impregnated.
I put a brushless and Lipo for power and the model really motors. Looks like yours already has spray rails, I had to fit some on mine to keep the water out of the cockpit.
Look forward to hearing how you progress. A build blog would be welcome and would help others doing similar restorations
Dave