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: liveaboard@liveaboardnow.org 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 Liveaboard@liveaboardnow.org 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/liveaboard@liveaboardnow.org The Mailman Users Guide can be found here http://www.gnu.org/software/mailman/mailman-member/index.html
