"Green Eye" SOC indicator for lead-acid battery behaving strangely

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bob prohaska

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May 27, 2022, 11:51:36 PMMay 27
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A few days ago I started playing with a low cost inverter/charger
using a nearly-new Delco Voyager deep cycle battery. I'd charged
it carefully, connected it to the inverter and run the fridge all
night, using about 50% of the battery capacity. The green eye still
showed in the viewport, but the battery was down to about 12 volts
when resting. That seemed odd, but the test was otherwise a success.

I let the charger run during the next day and repeated the load test
over the next night. Same results as before. Green eye stayed green.

On the third repetition, the green eye turned what looked like clear
to me, a great surprise since the tag on the battery says green is
good, black needs charging and clear means replace the battery.

I tried recharging the battery, which seemed to work (normal current
draw and voltage rise) but the green ball never came back in view.
Thinking I had a low electrolyte level, I reported the battery for
a replacement, which O'Reilly's provided without question. While waiting
I again cycled the battery. Same story, electrically normal but the
green eye stayed clear.

When I tested the replacement battery the green eye went clear at the
end of the overnight load test and it turned green again after about 9
hours' charging at 15 volts. It was still drawing a couple of amps, so I
let it charge further and in about two hours the eye went clear again.

There's no way I dessicated the battery in two hours at 15 volts,
I'd have been smelling it. It's hard to imagine what might make
the hydrometer ball vanish from view.

I now doubt _either_ battery is faulty, but can't guess what's
going on.

Anybody seen something like this?

Thanks for reading,

bob prohaska

Jim Wilkins

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May 28, 2022, 7:29:43 AMMay 28
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"bob prohaska" wrote in message news:t6s686$jqu$1...@dont-email.me...
----------------------------

https://carput.my/the-truth-about-car-batterys-magic-eye/
Removing the caps and checking all levels and specific gravities is more
certain. Be careful.

https://www.usbattery.com/elcetrolyte-levels-deep-cycle-batteries/

https://bobistheoilguy.com/forums/threads/battery-electrolyte-level.249776/

"A Google search shows that you are correct in first only filling to just
above plates (if low), then charging it. Various sources say after charging,
then fill to 1/4 inch below the vent well, 1/8 inch below, or just barely
touching the bottom of the vent well, depending on who you want to believe."

The only easily visible level indication is when the level touches the
bottom of the well and shows curved edges (meniscus) in the flashlight's
reflection. I think filling to that level when the maker suggests 1/4" below
it reduces the specific gravity a hydrometer reads, but doesn't change the
amount of acid. I've called East Penn's tech support line and received
further instructions, you could call Clarios about yours.
https://www.clarios.com/contact-us

The level increases during charge and decreases during discharge, as the
acid moves to/from the water into the plates. Top up the level with
distilled water only after fully charging the battery.

bob prohaska

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May 28, 2022, 12:04:28 PMMay 28
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Jim Wilkins <murat...@gmail.com> wrote:
>
> https://carput.my/the-truth-about-car-batterys-magic-eye/

That's the illustration that's got me so confused.

From the diagram it's very hard to understand how the ball
can be made to dissappear once the battery is fully charged.
Two hours at 15 volts seems unlikely to electrolyze much
of the liquid, especially without hint of heat or odor.

Is it possible that the newer "magic eye" devices have somehow
changed? This Delco battery was made in Korea, my other units
were much older and likely US-made. The last one has a two
color (red/green) indicator.

> Removing the caps and checking all levels and specific gravities is more
> certain. Be careful.
>
> https://www.usbattery.com/elcetrolyte-levels-deep-cycle-batteries/
>
> https://bobistheoilguy.com/forums/threads/battery-electrolyte-level.249776/
>

Agreed, but the baffling battery has a sealed top. Seems reckless
to go prying it open until the warranty expires. If I could pull
out the magic eye without leaving marks on the case it would be
somewhat tempting. Interestingly, it looks like my old Delco
Voyager has removable caps.

Thanks for writing,

bob prohaska

Jim Wilkins

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May 28, 2022, 2:07:00 PMMay 28
to
"bob prohaska" wrote in message news:t6th6a$2rs$1...@dont-email.me...
-----------------

Note to self: Maintenance-proof Johnson / Clarios batteries are unsuited to
DIY experimentation. Stay with East Penn.

Do not open! No user serviceable parts inside:
https://www.youtube.com/watch?v=-c6A1THDaeU

For training I've taken an analog+digital integrated circuit chip apart and
reconstructed the schematic.

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