Hear are the components you will need to make a light simple rechargeable Bulge pump.
Remove the plug that comes with the charger and fit one of the waterproof plugs you have bought to the charger. checking the polarity + to +/ – to –
The plug you have removed from the charger use this in your wiring of the box to connect to the battery. See photo.
I think it is worth adding a fuse as the battery is a high amp battery.
I find the battery last a long time but that will depend how much your Yawl leaks.
You will need some wire to extend the pump wiring, and fit the other waterproof plug you have bought to the pump, again get the polarity the right way, red to + / blue/black to -.
I have fixed the box in place just under the deck on the stringers with some bungee cord for easy removal.
Fitting the pump, best to get a piece of thin wood and make a pad and using some Silicon or similar stick this to a plank near the plate box, and screw the pump to that rather than screwing into a plank. Then drill a hole in the top of the plate box under the thwart seat and fit the pipe fitting.
Links to websites where you can buy the components
The links may change
Fuse Holder This can be bought in the boat store
5A Car Fuse This can be bought in the boat store
Waterproof Socket you need one
Waterproof switch cover This can be bought in the boat store
Toggle Switch This can be bought in the boat store
Rule Bilge Pump 360 GPH Submersible 24DA This can be bought in the boat store
Hose Coupling This can be bought in the boat store
Vapextech 12V 4600mAh NiMH rechargeable battery pack
Vapextech Charger Battery NiCd/NiMH 4.8V 6v 7.2v 8.4v 9.6v 10.8v 12v UK Plug