The crisis officially ends

So last night, keeping an anxious eye on my voltage readout, I celebrated bedtime by doing something I haven’t bothered with in years: I went out to the powershed and turned the inverter right off. This left me with lights* but eliminated the usually-but-not-right-now insignificant parasitic draw from the inverter. Three days with no sight of my shadow had finally pushed my much-improved electrical system back to where it was in 2013 or so.

None of this would matter to a normal person: Batteries are expendable commodities and numerous neighbors find out theirs are low when their inverters shut down. Long-time readers know I went through a lengthy period where I scrounged all my infrastructure and a single shorted cell on a worn-out second-hand battery could be a disaster. I grew used to babying batteries. And as of this past summer I have four new batteries for the first time ever, and I’m sure my ex-wife would complain that I treat them with more consistent loving-kindness than I ever showed her.

So this “crisis” is for informational purposes only, is what I’m saying. I never came close to involuntary inverter shutdown.

Anyway: I got up, took care of TB’s needs, and went outside to switch the inverter back on. Came in and recorded voltages…


The upper read-out is for the main battery bank, four T105s connected to the inverter. The lower reading is for 2 older (very old, and just showing signs of failure) T105s that run my 12-volt lighting. Since the beginning of winter those two batteries have begun to track consistently lower voltage even fully charged, and they discharge a tiny bit faster. With the inverter off all night we just barely bumped down below 12.0 volts (no load) for the first time … ever, really. I took that pic at 7 am, and watched carefully while doing other things. The sky cleared overnight so I knew we’d be on the road to recovery as soon as the voltage began ticking upward…


…which it did more or less the moment the sun peeked over the ridge.

So that’s good to know – on the fourth day I’d either have had to ration electrical usage or give serious thought to whether hooking my battery minder to the battery bank as a whole would actually work. Pretty sure it would work in a straightforward manner – it works on 2 batteries, why not 4 – but I’ve never really tried.


* Much of the main cabin has been retrofitted with 12 volt LEDs, and the addition has nothing but. So all I really needed the inverter for was charging wireless devices and of course the vital task of grinding coffee.

About Joel

You shouldn't ask these questions of a paranoid recluse, you know.
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3 Responses to The crisis officially ends

  1. Zendo Deb says:

    Batter chargers are a bit tricky to size for large banks. I don’t have the figures in front of me, but you can’t hook any charger up to any size bank. (There is some ratio of something along the lines of maximum amps out of the charger to amp hours of the battery bank) It only really gets crazy as the size of the banks gets larger.

    I had 600 amp-hours, more or less, and my small charger (which granted, was old) was struggling. And yeah, 600 amp hours was too much, because my solar couldn’t keep the fridge going, and it was overkill for everything else I needed, which was mostly lighting. Though the autopilot could use a lot of power.

  2. Norman says:

    Don’t forget your EU2000 has a 12 volt 8 amp output circuit; if you don’t have a charging cable for it, I’ll get you one.

  3. Joel says:

    I thought of getting one of those cables but my Battery Minder does that and lets me choose between 2, 4 or 8 amps. And I already have it.

To the stake with the heretic!