by golden_guppy » Fri Jun 22, 2007 10:51 am
Hi Beshires1
It looks like I'm doing something very simmilar to you. I'm currently working on a sealed cell setup myself, though only 5 cells at present while testing the theory. right now everything is glued and epoxied together,so not a pretty sight.
I like you idea of fitting the tubes at the corners. Didn't think of that, i have tubes fitted centrally at the top and bottom of each cell. I'm guessing the pinching isnt as bad in your design. I have 5 sections of pipe being used as reservoirs for the cells, but i'm looking at using these only as a 'buffer' with another larger central water tank feeding them, and keeping them topped up.
The idea was to use reservoirs just a little taller than the cells themselves. Both tubes from each cell are connected to the reservoir, the tube from the bottom of the cell going to the bottom of the reservoir, likewise with the top. I have another tube going from the top of the reservoir to a central bubbler, and finally another tube is fitted to the bottom of the reservoir to be connected to a central 'top op' tank. Right now these are just clamped off and go nowhere.
One of the things i'm working on now is a mechanism fitted to the top of each reservoir that will initiate a 'top up' automatically from a centrally located water tank.
I have found a few companies here in the uk that supply small solenoid water valves where the actual valve fitting itself is fully sealed, and each side is electrically isolated from the other. The idea is to have one central water pump send water through an automatic filling system to each cell's mini reservoir via one of these valves. I had initially though of filling directly to each cell, but gave up devising a way to stop over filling and pressuring the cells.
In theory, an automatic filling system shouldn't be too complicated, though eliminating current leakage is. What i'm aiming at is having a simple water pump fitted to a central water tank. This is in turn connected to the bottom of each reservoir. What i want to do is run this in short bursts. each supply valve would need to be connected to a switch of some descripton fitted in the top of each reservoir, that in turn will cut power to the solenoid when activated. This should be a pretty straight forward circuit. Downside is i need one for each cell. Anyway, this way, leakage current will only rear its ugly head during the brief time the cells are being filled. Once the solenoid valves are closed, all cells are fully electrically isolated again.
I want the automatic filling system to be scalable, so i can use it to supply more than one bank of cells. Was aiming at allowing capacity for 4 banks of 7 cells.
Anyway, thats where i'm at now. Assuming i can get it all to work. And blag my way into a few of these solenoid valves.