Lee,
Thank you for the great information about the submarine batteries. It correlates well with the information I have read in Home Power magazine. It was interesting that you used the actual working load to determine battery capacity rather than any battery spec. I have noticed that my AH meter tends to accumulate errors so that after a while it says the battery is charged when the hydrometer says it is not. Encouraged by your experience that your AH meters were "quite accurate" I will look into this and perhaps I can change some parameters to make mine more accurate. I'm sure that reliability is of greater concern that cost effectiveness on a sub compared to our little boats. Rolls cells were quite expensive in the past, and now that lead has gone up 250% (I just replaced my four Trojan L-16 house batteries at a cost of over $1000) cost is even more of a concern to us. I also find it interesting that you routinely "jumpered" bad cells. I had three bad cells in my house bank and that is the reason I replaced the entire bank. It makes me wonder what the ongoing cost of the bank would be if I used separate cells and replaced them only when they failed (shorted) since you did just that and got a 10 year +++ life. I only got four years from my last set of L-16 batteries. If you can say, what was the total voltage of your submarine battery bank? You information will be a great supplement to what we have already learned. Thank you... Norm S/V Bandersnatch Lying Julington Creek 30 07.695N 081 38.484W > [Original Message] > From: LA Licata <[EMAIL PROTECTED]> > To: <[email protected]> > Date: 11/19/2008 5:53:00 AM > Subject: Re: [Liveaboard] Submarine Battery Discharges > > Norm, > > The normal charge was determined to be over when the amount of amps > in remained constant over a period of time (5 minutes?). The > equalize charge was determined to be over at a calculated voltage > that was steady for a period of time (30 minutes?) adjusted for cells > present and temperature. The initial rate of equalization is > calculated from the amps just discharged along with a hydrometer > check of some key cells. There are also some absolute time limits to > make sure we do not "cook" the battery. > > AH meters were used and are quite accurate, and their performance was > checked by calibrated hydrometers and other meters available to us. > > Jumpered cells: I cannot remember the number allowed, but I think it > was no more than 5%, but not 100% sure....There is only one string of > 2.2 vdc cells on the nuclear subs I was on. Spares are NOT installed, > but if one approached the 5% limit early in the life of the battery, > I understand that new cells will be swapped for the jumpered ones. > never experienced this though... > > The discharge rate on the battery is NOT set by the battery, but by > the power needed over a period of time to support the safe shutdown > and restart of the reactor that has been operating in such a manner > as it requires the max amount of electricity to be safely shutdown. > If the battery cannot provide, it is replaced.... Again, never > experienced this in actual fact. (Same EXACT rule exists as civilian > nuclear power plants.....!!) > > Gasses: During equalization, we monitored the h2 produced and have > ways to route it into the ship and then overboard . I do not remember > ever having a h2 concern except under unusual circumstances. > > Rolls 2.2 vdc industrial cells are built somewhat like the batteries > on a nuc sub.... I think it is fair to say that you do get what you > pay for.....in this case....if maintained properly.... > > Lee > > > On Nov 18, 2008, at 2105, Norm of Bandersnatch wrote: > > ....How was the State Of Charge determined. I know that my AH meter > accumulates errors and that my hydrometer is the final word. Did the > submariners rely on an AH meter or did they dip the hydrometer or both. > > You mentioned they "jumpered" bad cells. How many cells were in a > string. It must have been many to tolerate taking some out of the > string. Did they carry spare cells to replace the ones jumpered. I > imagine they were quite large and hard to move, but there could have > been "spares" installed at the end of a string that could be > maintained by a special charger and jumpered in as needed. > > How did you determine the discharge rate to do the capacity test. > > What did you do with the gasses when equalizing. Did you burn them > or store them or what? What rate did you equalize at and for how long? > > I would love to get a decade out of my house batteries. > > > Norm > S/V Bandersnatch > Lying Julington Creek > 30 07.695N 081 38.484W > > > > ----- Original Message ----- > From: LA Licata > To: [email protected] > Sent: 11/18/2008 12:30:58 PM > Subject: Re: [Liveaboard] Submarine Battery Discharges > > Hi! > On nuke subs, we tricked discharged our lead acid battery bank at 5 > amps every hour for every day when the battery was not being used as > a power source. When used as a power source, after the event, the > electrician on watch at the electrical panal would get permission and > commence a "normal" battery charge to get the amps taken out back in. > > Once per month, we discharged it to 50% of CALCULATED capacity at a > controlled discharge rate and recharged it normally to verify > calculated capacity. > > Every 6 months we did a test discharge (after inspection and water > level check) from 100% capacity to verify that it operated per > designed, as compensated for any cells jumpered, and then equalized > it. We then reran the capacity number checks. > > While the distinction between the data collected may appear to be > small, it is not > > This is my memory serving me. the time frames can be wrong, but I do > not think so. > > If I also remember, we tended to do the equalizers at sea as the the > motor generators could easily really "reach and maintain ordered > amps" that was needed at the start of the equalizer. > > Only the reactor got more care and better feeding than the battery. > And, batteries lasted a real long time, like decade ++++ > > Lee > _______________________________________________ > Liveaboard mailing list > [email protected] > To adjust your membership settings over the web http://www.liveaboardnow.org/mailman/listinfo/liveaboard > To subscribe send an email to [EMAIL PROTECTED] > > To unsubscribe send an email to [EMAIL PROTECTED] > The archives are at http://www.liveaboardnow.org/pipermail/liveaboard/ > > To search the archives http://www.mail-archive.com/[email protected] > > The Mailman Users Guide can be found here http://www.gnu.org/software/mailman/mailman-member/index.html _______________________________________________ Liveaboard mailing list [email protected] To adjust your membership settings over the web http://www.liveaboardnow.org/mailman/listinfo/liveaboard To subscribe send an email to [EMAIL PROTECTED] To unsubscribe send an email to [EMAIL PROTECTED] The archives are at http://www.liveaboardnow.org/pipermail/liveaboard/ To search the archives http://www.mail-archive.com/[email protected] The Mailman Users Guide can be found here http://www.gnu.org/software/mailman/mailman-member/index.html
