Both cases started with new batteries: Trojan L16s. One was a 24 v system that tapped for 12 v lighting, the other was a 48 v system that charged with a 24 v Bergey added later. The problem seems to come up when you have more than one parallel string. I could see the Vanner working on a single string. The imbalance showed up just barely at first, and got much worse with time. In the end, the L16s died in less than 5 years, and never provided their full rated amp hours even the first year. DC to DC converters from Solar Converters, Inc. seem to work pretty well, but I always under load them (maybe 5 to 10 amp load on a 20 amp rated unit) THese days I just go all AC and avoid multiple DC voltages in the first place. There is almost always another solution. A fair bit of our rewire work these days involves converting DC circuits (lighting, etc.) to AC under the K.I.S.S. principle.
R. Walters r...@solarray.com Solar Engineer On Sep 3, 2011, at 9:10 PM, boB Gudgel wrote: > On 9/3/2011 7:57 PM, Darryl Thayer wrote: >> >> I have had one experiance with equalizers, the batteries be came very >> unequal. (over time of course) >> >> From: R Ray Walters <r...@solarray.com> >> To: RE-wrenches <re-wrenches@lists.re-wrenches.org> >> Sent: Saturday, September 3, 2011 5:55 PM >> Subject: Re: [RE-wrenches] unique battery bank design question >> >> Systems I tried years ago with Vanner equalizers, still ended up being >> unequal. I pulled them all years ago. It seems to be about as much a problem >> as not balancing your battery cables so each battery string has the same >> wire resistance, >> I know that you couldn't imagine a few amps on 12" of 2/0 making a >> difference, but after 5 years the battery damage is very consistent and >> identifiable. >> The only load I would consider tapping would be metering, or maybe a low >> milliamp relay. I wouldn't go over 100 mA, and even then I bet you would see >> some long term imbalance. I've seen imbalances due to some batteries just >> being closer to a cold outside wall. >> >> R. Walters >> r...@solarray.com >> Solar Engineer > > > Has anyone that has used battery balancers checked the individual battery > voltages or SG during charge and/or discharge to > see how well the balancers worked ?? > > Could it be that the batteries themselves were just not quite the same age at > the start ?? > > I would think that a decent balancer system that makes things share should > work pretty well. Maybe the balancer > itself does a bit of unbalaced charge/discharge ? > > boB > > > _______________________________________________ > List sponsored by Home Power magazine > > List Address: RE-wrenches@lists.re-wrenches.org > > Options & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: > http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out participant bios: > www.members.re-wrenches.org >
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