Today I finally realized that my current house battery, bought from Walmart about three years ago, was toast.
I had a long call with RichardM and his explanations of the behavior I was seeing on the new battery monitor finally got through my thick head.
So I went ahead and removed the bad house battery, drove the Sammy over to the nearby city of Truth or Consequences and bought the same model at the Walmart there. It's rated for 122 amp hours but per RichardM's suggestion, will set the monitor for 110 amp hours to ensure I never go below 50% on the battery!
Some notes:
When I woke, the monitor reported a voltage reading of 12.17, less than 60% and this was after setting things to account for the battery's ability to only hold 50 amp hours! I started up the generator to start the recharging process as I didn't want further damage to the battery if it reached below 50%. Well, it was too late, the battery just was too damaged from the last three years.
Talking to RichardM, I learned that if the voltage jumps immediately to 14.5 on the battery monitor, then there's something wrong with battery, it's not accepting the charge from shore/gen power. I had believed the voltage shown was what was coming from the power source, wrong!
It should, start at whatever voltage, say 12.17v in my battery's case and slowly climb to 12.5/6 volts or so. Amps coming in should be around 10a or so (this from my small generator) and steadily go down to around 5a as the battery charges back up.
Once at 5a input amperage, the battery is in Absorption mode and is basically at 80% charge or so. It'll take many hours to reach 100% at which point it should display 13.5v which is Float mode. Sure, you can continue using your generator and fuel to continue charging but it's not efficient.
13.5v indicates battery is full and will not accept further charging from power source.
In my case, when at 5a input I should consider switching to solar panel for charging since it'll take hours and my current solar setup should provide 5a or so, of course more is better and that's in my future possibly.
Oh, and when hooking up the HF charge controller, don't forget putting the negative connector on the shunt, not directly to the battery because then your battery monitor can't read what's being input by the solar panel! RichardM spotted this error on my part as we talked. Sigh.
Now I can see amps coming in from the solar panel where before I couldn't! Once the generator got to less than 5 amps, I switched to the solar panel for the rest of the day. I was even able to recharge all my electronics, use the laptop for picture processing AND still around 2 amps going into the battery! I am optimistic I've got things set up well now.
If I end up near Phoenix later on, I may have to drop by the San Tan Solar Panels company and explore getting a larger solar panel. Perhaps just swapping the battery will do just fine, I guess I'll see in the next few days/weeks.
Here's a pic of when I was back in the City of Elephant Butte picking up something from my Samurai-driving friends this evening.
3 comments:
"It's rated for 122 amp hours but per RichardM's suggestion, will set the monitor for 110 amp hours to ensure I never go below 50% on the battery!"
Something doesn't add up there ...
Bocutter Ed, you are not supposed to go below 50% of a flooded lead acid battery capacity since this will damage it in the long run. I am going to use 110 amp hours, which translates to 55 amp hours of usable capacity. Since it's really rated for 122, this gives me a little bit of a safety margin as well. Hope this answers your comment.
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