“If you use desulfators, the life cycle issue essentially disappears, as long as you check electrolyte levels at no more than 90 day intervals. My oldest bank of batteries is now 14 years old and still performing as new.”
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Lots of great info on the thread thanks everyone. Do (sealed) lead acid batteries have the electrolyte issues you mention (presuming one cannot check since they’re sealed?)
In the spirit of doing everything small to start, currently using a 1-amp motorcycle desulfating trickle charger on my battery - hoping that will keep it from konking out from being cycled too far... Works for the little battery as a backup for the small solar panel (just 5 watts to start), and supposedly desulfates. So desulfating is a critical part of all this, I’m learning?
Some humor - about 2 hours ago I decided to test out my tiny backup rig to read FR. Got my pc powered 12v dc through a small car cigarette lighter inverter, which I hooked with an adapter to the tiny 8 amp-hour battery. Everything came up, and I went on the internet aok in something of a power-out simulation. Still relying on the isp connection, but everything beyond the wall connection anyway, was off-grid.
I logged into FR, and started to say the experiment was working great. I had a voltmeter hooked alongside, and was monitoring my voltage - which started about 11.8 volts when i logged on.
The DMM initially dropped to around 11.5 volts at boot, and hovered there a few minutes. Long enough to read Drudge, look at headlines, and then log into FR.
Initially I had thought I could ride the battery charge down to maybe 8 volts - but once it fell to just above 11 volts everything just shut down. Just plain *click* and everything went blank.
So the small battery, and a day’s worth of solar charge on the basic 5 watt solar panel (appx 1.5 square feet) seems to be enough for maybe 30 minutes of backup internet. After which I should still have enough left in the battery, to run a 12v low-voltage light overnight until it can be charged again solar the following day.
Not much, but it’s a start. :) Fun too, if one enjoys this sort of thing.
Slowly scaling this up, so far so good...
Gell cells and AGM cells are sealed completely, so there is no electrolyte issue.
Both of those are very sensitive to deep discharging, which is why in systems that are expected to need to deep cycle, lead acid batteries are usually used.
In the case of your small inverter, there is a processor chip controlling it and it should sound a beep at 11.5 volts, and shutdown at 11.0 volts.
Q-cell 20 watt solar panel $59