From: John De Armond Subject: Re: Battery - Red Eye Remains Date: Sat, 18 Mar 2000 16:16:54 EST Newsgroups: rec.boats,rec.outdoors.rv-travel Kit Maloney wrote: > > My trolling battery is about a year old but sat for six month without being > used. It now has a "red eye" instead of a green eye. Using my onboard > charger didn't change the eye back to green overnight, so I took the battery > out, put in on a regular 15 amp charger (set in Deep Cycle mode) and ran it > for about 6 hours until the "charge complete" light came on. > > Problem is that the light is still red, not green. The unloaded voltage > across the terminals is 12.9 volts. Should I be concerned about the "red > eye"? Is there a charging routine that I can use to restore life to this > underutilized battery? Run an equalizing charge on it. The indicator works on specific gravity. The electrolyte gets heavier as the battery charges and sulfuric acid is emitted from the plates. If the battery is just charged and not equalized, the acid tends to remain down in the plate area (heavier than the lighter depleted electrolyte on top) and your eye can't see it. Sloshing the battery around a bit can stir the electrolyte but the easiest way is to overcharge it (equalize it) until vigorous bubbling occurs. This will stir the electrolyte. If the eye's still not green, then the battery is probably sulfated and may or may not be recoverable. Note that the eye is only "calibrated" at near room temperature so if your battery is very cold or very hot, it will not indicate properly. John From: John De Armond Newsgroups: rec.outdoors.rv-travel Subject: Re: To equalize or not to equalize Date: Mon, 04 Apr 2005 19:08:58 -0400 Message-ID: <i9h351dn7a5o63362a7cjst5ci1gna0dtd@4ax.com> On Mon, 04 Apr 2005 14:45:57 GMT, "Frank Howell" <fphowell@sbcglobal.net> wrote: >My MH battery bank consists of 3 Trojan SCS200(115ah). I have read articles >on the benefits of equalization for deep cycle batteries, but I would like >to hear from anyone who has actually done it. OK. I equalize my RV's house batteries several times a year. Equalizing does several things: * It brings all the cells up to full charge. This is probably the most important function. Left to their own devices, the individual cells will drift apart in their capacities and therefore their states of charge. This happens mainly because of the formation of hard sulfate crystals on the plates of the stronger cells when they're not fully charged. Another cause is unequal shedding of the plates. * It stirs the acid, making your hydrometer readings actually mean something. * it helps remove shedded material from between the plates where it can settle to the bottom of the cells. Shed material tends to raise the impedance of the affected cell which is not good. There are many opinions on when to do the equalization. I do it every 15 to 20 charge/discharge cycles. The reason is that I don't want to give the unconverted lead sulfate in the less-than-fully-charged cells time to harden up to the point that it can't be converted by normal charging. It doesn't take much current to do an equalization cycle, perhaps 5 to 10 amps per battery. I have two Group 29 batteries in my rig. I use 10 amps, 5 per battery, starting out. I built a variable voltage battery charger to do mine with. There are any number of ways to do it with improvised equipment. Two battery chargers in series and in series with a sealed beam headlight (passes about 5 amps over a wide range of voltage) will do the trick. As will two batteries in series with the lamp, a battery and a charger in series, etc. Don't worry about the voltage too much, just keep the current down. Yet another way is to use a dumb charger with the "boost" or "jump start" option. This feature cranks out >15 volts on the chargers I've looked at. You can control the current either with the sealed beam headlight or you can use a light dimmer (rated for motor speed control) to regulate the 120vac going in. Harbor Freight has a "router speed control" rated for 15 amps on sale right now for $9.99. I just picked up a couple for general purpose AC voltage control. I equalize until all the cells are gassing more or less equally and until the specific gravities quit changing. Usually no more than an hour after the batteries are fully charged with my Vector smart charger. That's about all there is to it. John |