• Battery Woes update...

    From Flying Pig@21:1/5 to All on Mon Jan 2 16:26:48 2017
    Battery Woes update...

    When you last saw this title, we had our 4xL16, bank 740AH, batteries which weren't performing to our satisfaction.

    Several pros chimed in and either posted in one of the places I posed our issue, or wrote to me directly.

    Symptoms, they agreed, pointed to chronic undercharging. Likely the cause
    was promoted by either and/or both being misled, perhaps, by our Tri-Metric 2022 monitor, as the batteries aged, or merely our not letting them charge fully enough before shutting off our Honda 2000. (Recall that we have 370w solar, KISS wind generator, 1500w/70A inverter charger and 40A shore
    charger, plus a 70A alternator when we motor - which in our charging scheme,
    is nearly never.)

    Cure, the pros (and industry literature I got keyed to or sent) suggested, might be repetitive cycles of deep (50%) discharge, followed by full
    charging and then 3 hours of equalization.

    We moved onto a dock to be able to take advantage of the adequate power to
    run both our 70A inverter/charger, and our 40A shore charger. We also
    followed one's suggestion of getting a 200W bulb, and running all AC devices possible (to the max 1500W) and everything we could turn on to achieve a quicker draw--down. So, oddly for us, of course, instead of trying to
    minimize use, we were maximizing it, turning off our shore power at night. Having every light in the boat on, every fan, and our freezer set to a place
    it could not achieve (run at high speed all the time), all charge-able items connected to AC and the lamp and a fan running on the inverter and the
    battery box, at night was a bit disorienting.

    We then reversed the procedure, turning on the shore power (for the
    chargers), running our freezer set point up to its minimum use and turning
    off every other load, in order to charge as quickly as possible.

    We allowed for an all-day charge cycle, with whatever assistance was
    available from wind and solar, and then equalized after dark before turning
    off the shore power and starting our drain.

    All along (from start through this point), bank (12V battery) 2 was always hotter than bank 1 (in parallel to bank 1), and it got pretty warm along the way, which I think caused the heat probe to throttle back the amps, but kept the voltage up during some of the equalization cycles. For several days, it looked promising, as the consumed AH went deeper each time, before it got
    low enough to kick out the inverter or the freezer. However, the deepest we could get it was 40% discharged before it got low enough (11.3 or so; we
    were asleep so I never actually saw that happen).

    So, we let it rest for a couple of days on shore charge, making it fully charged, and equalized occasionally. Yesterday I equalized 3 separate
    times, and then we read the specific gravities. All were markedly improved from where we started, and, unlike the first time, when bank 1 was at
    ambient, but bank 2 at elevated temperatures, this time both banks were elevated in temperatures. We adjusted with our temperature-compensated hydrometer, but didn't top up bank 2, which had used rather more water than
    we had found in our initial equalizations. I assume this would have led to slightly higher SGs than was warranted had I topped them off, and equalized again.

    So, bank 1 is batteries b1&b4 and bank 2 is b2&b3. Temperature adjusted SGs were, in order (1-12, moving clockwise from the first cell, all
    one-dot -1.xxx - values): 263, 258, 263 (b1), 334, 319, 319 (b2), 319, 319, 319 (b3), 258, 258, 258 (b4)

    So, with one exception, all cells were essentially the same per battery, and within margins to be 'not bad' cells. However, Bank 2 (b3&4) was still undercharged, despite being hotter (19 temp adjust vs 8 on bank 1). Hm.

    So, I decided to swap b3 and b4, changing one each, to see if that changed matters. These weigh 125# each, so I knew it would be a wrestling match.
    After unhooking, and taping off, the necessary leads to allow those two to
    be lifted out of the box, I started. Hm. Not only is it heavy, but it
    seems to not want to come more than a few inches up. Muck around with the lifting straps we'd made, but since these were able to fit into the box with their original handles still attached, used those. Made sure the straps
    were clear, and tried again to use the straps.

    Same deal. Hm. Strong light down the sections between the batteries.
    Oops. The interior short side (between b3 and b4) of b4 was seriously
    bulged. If one cell is bulged, even though the specific gravities were the same in all but one (263 vs 258) of the cells in bank 1, the whole system is dead. That bank 1 was not even fully charged just confirms it. However, I speculate, as it's well into the charge range, that bank 2 (5 cells 319, one 334) is just fine. If someone wants them for more than whatever the core charge would be, I'm happy to have you get them in Vero Beach City Marina.
    We'd have to coordinate with my new batteries, in order that I still
    function aboard, of course.

    So, now starts the challenge of finding some solution which won't be any
    worse than I know it will have to be, most likely well over a boat buck. Scuttlebutt at one of our cruisers' Monday Night Burger Night (the source of all my Mr. Manatee tee shirts I earn for me, the admiral, and her kin) had someone here renting a car and driving to Miami, the savings were so significant; that's a possibility, I suppose, but having an able-bodied assistant in getting these out, and the new ones in, might be necessary; a delivery would have the appropriate personal strength and equipment to make
    the transfers more routine.

    What I'm going to be looking for will be L16 (floor sweeper, e.g.)
    batteries, preferably high capacity (over 400AH), vertical lugs taking

    Various pros have expressed that my charge sources - aside from more solar being always a good thing - are fine, but that I need to reset my monitor to new or zeroed values every time I equalize, and spend a great deal more time
    in my float-off charging. The best solution for US will be to nearly double our solar capacity with two 345w panels, exchanging for our 3 (370w, 11
    years old and not nearly as efficient as the new ones would be), as we have
    the available real estate in roughly the same size as our current solar
    array, and our MPPT charger can handle those effective amps. So, I need to move that up on the priority li$t; if we had all that solar (usually), not
    only would we not be as deeply depleted, but our float-out would have ample power every day, not waiting for our Honda to drive us deaf.


    Do you want a pair of 30-month old L16s, cheap?


    Recommendations for the least expensive solution to 4 more batteries in Vero Beach FL?

    Thanks, all, for reading this far and for all the assistance which has been previously rendered.



    Morgan 461 #2
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