Yes, a shorted cell will be very watery. And, as I remember, soot sucked up into the hydrometer too.
Interesting to hear that there is a movement away from Trojan in the "off-grid" folks. Will have to keep an eye on that. "Shotgunning" sounds familiar; they called it "Easter Egging" the last time I was in tech school. Go for the easiest thing first. We might get lucky. And it might be "instinctive". Maybe the whole battery was sulphated or otherwise no good, not just an individual cell. I can't understand why defects do not show up with a hydrometer. Charging and discharging is essentially a transfer of sulpher from the plates to the electrolyte and vice-versa. If lots of sulpher is in the water then the batteries are charged, and vice-versa. Norm S/V Bandersnatch Lying Julington Creek FL N30 07.68 W081 38.47 > [Original Message] > From: Ben Okopnik <b...@okopnik.com> > To: <liveaboard@liveaboardonline.com> > Date: 11/23/2010 8:25:38 PM > Subject: Re: [Liveaboard] Batteries > > On Tue, Nov 23, 2010 at 07:26:12PM -0500, banders...@earthlink.net wrote: > > > > The shorted cell will rapidly discharge itself so a shorted cell will have > > a very low specific gravity. The hydrometer float will barely rise. > > Thanks, Norm. That's what I figured, but without actual experience with > measuring a shorted cell, there was always that tiny bit of doubt. > > So I'm just where I was at the beginning: a fault in a battery that > isn't a shorted cell and doesn't show up with voltage, current, or hydro > measurements, but nevertheless results in reduced (almost zero) storage > capacity, (presumably) causes the regulator to overheat and shut down > every ten minutes or so, and finally shorts and fries the batteries. > > That's really annoying - but fortunately not a "live" experience > anymore... and, hell, shotgunning can indeed be a valid troubleshooting > technique at times. I'll know what to do about it (disconnect the > battery banks one at a time) if I ever see it again, anyway. > > > Been there, done that. Cost more that $1000 for four new L-16s. > > I've been doing a lot of research online with regard to golf cart > batteries, and it seems that a lot of "off-the-grid" and RV folks really > like the US Battery 2200 XC golf carts: the same size and nearly the > same capacity as the Trojan GC-2s (220 vs. 240), but $72 apiece at Sam's > Club. If they survive 2 years, they will have more than paid for > themselves by comparison to Trojans or SeaVolts. > > Representative quote from > http://www.cruisersforum.com/forums/f14/golf-cart-batteries-vs-marine-batter ies-34470-2.html : > > My high school friend manages a golf course down > on the Cape and three years ago they moved away > from Trojan over price. I think they now use > either Crown or US Battery, he told me but it was > at a party and clearly I forgot. Their failure > rate has remained unchanged since the switch and > they kill batteries to flat dead every day of the > season. They aim for 50-60% DOD but it does not > always happen. The batteries they are now buying > are costing them significantly less, perhaps not > 50% of the price of Trojans but close and they > are still US made. > > On the repairs front, the spare outboard was also out of commission > [laugh]. I just got it going again, so I'll be able to get to shore and > start the mad running around tomorrow. > > > -- > OKOPNIK CONSULTING > Custom Computing Solutions For Your Business > Expert-led Training | Dynamic, vital websites | Custom programming > 443-250-7895 http://okopnik.com http://twitter.com/okopnik > _______________________________________________ > Liveaboard mailing list > Liveaboard@liveaboardonline.com > To adjust your membership settings over the web http://liveaboardonline.com/mailman/listinfo/liveaboard > To subscribe send an email to liveaboard-j...@liveaboardonline.com > > To unsubscribe send an email to liveaboard-le...@liveaboardonline.com > The archives are at http://www.liveaboardonline.com/pipermail/liveaboard/ > > To search the archives http://www.mail-archive.com/liveabo...@liveaboardnow.org > > The Mailman Users Guide can be found here http://www.gnu.org/software/mailman/mailman-member/index.html _______________________________________________ Liveaboard mailing list Liveaboard@liveaboardonline.com To adjust your membership settings over the web http://liveaboardonline.com/mailman/listinfo/liveaboard To subscribe send an email to liveaboard-j...@liveaboardonline.com To unsubscribe send an email to liveaboard-le...@liveaboardonline.com The archives are at http://www.liveaboardonline.com/pipermail/liveaboard/ To search the archives http://www.mail-archive.com/liveabo...@liveaboardnow.org The Mailman Users Guide can be found here http://www.gnu.org/software/mailman/mailman-member/index.html
