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So far..... bank not wired properly, shunt may not be (I can't tell), likely different battery chemistry than the charge voltages are set for and the charger does not go from absorb to float intelligently (only on some arbitrary percent of capacity). With all those head scratchers, you're measure the bank that been unintentional charge abused, with a very precise instrument. BTDT.

If you're looking to get it right, you really need to clean it all up, get a good three stage charger, for the correct chemistry, that drives the switch from absorb voltage to float voltage off amp acceptance, or I think you'll drive yourself crazy looking for gremlins. I'm afraid I wouldn't rule out needing new batteries. I don't recall what's actual in there, other than the PO replaced them. Are they truly marine deep cycle batts?

Also note that amp hour counters are not exact. You tell it what your bank capacity is, but you're only guessing. All batteries lose capacity with age and use. Poorly charged batteries lose it faster. Then your capacity is based on the exact amperage draw that gets to that capacity in 20hrs. If you draw amps faster, the total capacity actually declines and vice versa. Most counters don't get this quite right.

The good news, if you can look at it this way, is the exercise has revealed some incorrect hacks by the PO that you can clean up. BTDT too.
 

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Also note that amp hour counters are not exact. You tell it what your bank capacity is, but you're only guessing. All batteries lose capacity with age and use. Poorly charged batteries lose it faster. Then your capacity is based on the exact amperage draw that gets to that capacity in 20hrs. If you draw amps faster, the total capacity actually declines and vice versa.
This article, while complex and long, deals with exactly these issues.

Making Your Battery Monitor More Accurate
 

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Discussion Starter #43
So far..... bank not wired properly, shunt may not be (I can't tell), likely different battery chemistry than the charge voltages are set for and the charger does not go from absorb to float intelligently (only on some arbitrary percent of capacity). With all those head scratchers, you're measure the bank that been unintentional charge abused, with a very precise instrument. BTDT.

If you're looking to get it right, you really need to clean it all up, get a good three stage charger, for the correct chemistry, that drives the switch from absorb voltage to float voltage off amp acceptance, or I think you'll drive yourself crazy looking for gremlins. I'm afraid I wouldn't rule out needing new batteries. I don't recall what's actual in there, other than the PO replaced them. Are they truly marine deep cycle batts?

Also note that amp hour counters are not exact. You tell it what your bank capacity is, but you're only guessing. All batteries lose capacity with age and use. Poorly charged batteries lose it faster. Then your capacity is based on the exact amperage draw that gets to that capacity in 20hrs. If you draw amps faster, the total capacity actually declines and vice versa. Most counters don't get this quite right.

The good news, if you can look at it this way, is the exercise has revealed some incorrect hacks by the PO that you can clean up. BTDT too.
They are maintenance free FLAs. They are tagged as marine deep cycle, and come from a reputable local battery company. I agree they have likely been abused, and will likely need to be replaced, however at this point we are getting enough out of them to be off grid for 4 days before recharging.

At this point I'm not too worried about the accuracy of the SOC feature on my monitor, I am more interested in measuring accumulated amp hours to judge whether my changes improve anything. I can judge state of charge based on voltage for now. The way I see it, I can learn on these batteries, sort out the wiring etc, and then once I have got the most out of this bank I can use what I have learned to make decisions about what direction I want to take when I upgrade. I don't want to replace my charger based on these batteries. If I am going to replace the charger with what is best for my next battery upgrade.

Sent from my SM-G960W using Tapatalk
 

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Discussion Starter #44
I rewired the batteries while were away this weekend. I moved the engine negative to the main negative bus, removed the extra negative connection from the house bank, and took the negative disconnect switch out of the circuit.

Now the monitor is making more sense. When on shorepower it shows infinite time left on the bank. When a load comes on the monitor at first indicates an amp draw, and then the the charger starts taking the load.

After rewiring the batteries and powering up the charger again it immediately ramped up and started putting 15 amps in to the bank. I assume that is an indication that all batteries were not getting fully charged in the previous configuration.

I will be interested to see if we get more AH out of the bank next time we are off grid.

Sent from my SM-G960W using Tapatalk
 
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