[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [PSUBS-MAILIST] Battery pod. (question for Dan H.)



Hi Bill,
 
Ok, I will build my pod with PVC. Now my question is: "If I compensate the PVC pod with air and since there is an amount of air INSIDE the battery case, will the battery case crack under preassure?"
 
What type of battery will you use? ADM or lead/acid?
 
Pierre Poulin
Québec Canada
 
----- Original Message -----
From: Akins
Sent: Tuesday, January 18, 2005 6:26 PM
Subject: Re: [PSUBS-MAILIST] Battery pod. (question for Dan H.)

Dear Pierre.
 
You said you never intended to go below 60 ft. At that depth you are not even at two atmospheres of pressure. Don't just take my word for it, ask others,
but I assure you that at that depth and pressure you will not have any problems with the thickness of a 10 or 12 inch pvc pipe. As you know I am using a 12 inch pvc pipe for my battery pod. Even if I did not
pressure compensate my pod it would withstand less than two atmospheres of pressure with ease. By pressure compensating it I just decrease the forces against it
from the water pressure on the outside and help preclude any leaks, but I probably wouldn't even need to do that at only 60 feet. Go to this ROV site and post and ask
this question there. They helped me out a lot. Here is the URL    http://groups.yahoo.com/group/robotrov/?yguid=204005530
Bill Akins.
 
 
----- Original Message -----
Sent: Wednesday, January 19, 2005 7:03 AM
Subject: Re: [PSUBS-MAILIST] Battery pod. (question for Dan H.)

Hi guys!
 
Well, it's not a matter of: is PVC better then steel... You see, I have enough skills as a machinist to build the pod myself in steel at very low cost. That is why i prefer steel. It's only a personal preference. That said, the real question I have in my head is, will I crack my batteries or not if i pressure compensate the pod? Be it in steel, PVC, wood, etc... My opinion is that since the is an amount of air INSIDE the battery case, I think the case will be stressed the same as if it was empty. And since it's a square plastic box, the resistance is not too great.
 
I may be wrong. And I would love to be wrong. It would be much easyer to pressure compensate the pod then build it to resist the pressure.
 
Anybody have a though about that?
 
Pierre Poulin
Québec Canada