Ian’s Electrical: Maybe this’ll do it…

I’ve had nothing but trouble with Ian’s new batteries, and for no good reason I could see. No matter how charged I thought they were by afternoon, the next morning the system had shut down with a “low voltage” error. Yeah, the new batteries are half the size of the old ones but that can’t render them completely useless. And yet – nothing was actually wrong but nothing was able to work for very long.

There was only one new element, and that was the batteries, and since there was clearly nothing physical wrong with them the only variable I could come up with was state of charge. It can take quite a while to really fully charge a big deep-cycle battery, let alone eight of them.

So I conducted a little experiment. I turned off every major appliance in the whole system – which consisted of the refrigerator, the pressure pump and the water softener* – while leaving the system itself active. Now the only serious drain on the batteries was the inverter itself.

The next morning, to my pleasure but not really to my surprise, the system was still running. I let this happen for two more days without difficulty, and the charge controller finally indicated a float condition, meaning that in its opinion the batteries were fully charged. For the very first time**.

This sunny morning I turned the pump back on and washed laundry. Now I’m going to leave it on and see if I get an error and shutdown overnight. The refrigerator can wait till I work out whether the fully-charged batteries will run the water system without glitching out.

We shall see. This has all been a lot more complicated than I hoped for.

*The water softener doesn’t actually pull much juice at any time as far as I know but it does regenerate periodically which requires a lot of water pressure which won’t happen without the pump which pulls a lot of juice, exclusively at night. So I turned it off just to simplify matters.

**I have a way of charging four batteries at once in my own powershed. I don’t know if the charger will do eight, or if the generator would power the attempt, but I do know that unbolting the charger from my own system and rigging it for Ian’s would require more effort than I’d be happy to call Plan A. Success might also involve dividing Ian’s batteries to two or four at a time for charging, which would kind of defeat the whole purpose of his PV system. So I just turned everything off and let the PV system charge the batteries at its own pace even if it took days. Saved gas, too.

About Joel

You shouldn't ask these questions of a paranoid recluse, you know.
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8 Responses to Ian’s Electrical: Maybe this’ll do it…

  1. Anonymous says:

    And, you were trying to do this a week before the Winter Solstice so the annual minimum available solar power. No wonder it took so many days to get them topped off.

  2. Anonymous says:

    I’m not trying to be a dick or anything….Im just genuinely curious: Didnt Ian used to work in the PV field? Might he not be a useful person to have take a look at this?

  3. Joel says:

    Ian briefly had a job selling PV racks, something like 12 years ago. That’s the full extent of his professional experience in the field. If it’s a particular interest of his he has carefully kept it a secret from me for a long time.

  4. Anonymous says:

    Different batteries, different charge controller settings?
    Those new batteries were probably not at full charge when installed?

    That’s my two shots in the dark..


  5. Anonymous says:

    Might want to change the softener regeneration to noon. I would think that would put a smaller hit on the batteries.

  6. matismf says:

    You might have saved gas, but that does NOT please Tobie!

  7. Anonymous says:

    I noted there is a book available on setting up a solar system on the cheap and it only costs $4.99…might want to invest in a copy.

  8. RCPete says:

    The charge controller probably needs a tweak for the lower amp-hour capacity of the new batteries. IIRC, the Rolls-Surrettes have about twice the capacity of the Trojans. (Looks it up: RS 428 amp-hours, vs 225 for T-105s)

    I’m not familiar with the Mate 2 controller; if there’s a paper copy of the manual, go for it. Otherwise, the manual can be downloaded from Outback. Depending on the precise version, it’s a different download, but it’s on this page:


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