Weird! -But okay now?

[Kirk]

On lead acid batteries it is more like 75% SOC.

 

[bigbAZ]

Mine are two Harris 6-volt batteries in series. Uses 13 mm bolts. I used a metal socket wench being extra careful.

Perhaps someday I will buy a set of these. There has been enough times I needed such a set.

-Don- Sac Pass, NV

A stubby ratchet with a bicycle handlebar grip slid onto the handle works pretty good. I've also used tape on various tools.

 

[boatbuilder1]

Glad you found the issue and it was a simple fix.
I have used heat shrink on the outside of sockets I wanted to insulate.
On batteries with bolts, the bolt is strictly for clamping force. The electrical contact is made to the terminal by the pad the bolt threads into.

 

[DonTom]

A stubby ratchet with a bicycle handlebar grip slid onto the handle works pretty good. I've also used tape on various tools.

Yeah, I have also done such things, but I didn't feel I needed to bother with any of that in this case, it I carefully watched what I was doing.

-Don- Sac Pass, NV

 

[DonTom]

A stubby ratchet with a bicycle handlebar grip slid onto the handle works pretty good. I've also used tape on various tools.

Yeah, I have also done such things, but I didn't feel I needed to bother with any of that in this case, it I carefully watched what I was doing.

-Don- Sac Pass, NV

 

[DonTom]

Not sure what batteries you have but 12.45 volts is not 97% SOC. On lead acid batteries it is more like 75% SOC. I am wondering if there is a loose connection that is making the system think it is low and causing the shut down.

Yeah, that was related. I have NOT recalibrated it but now my Smartshunt is showing I am at 12.64V @ 91%, which sounds like is about where it should be.

-Don- Sac Pass, NV

 

[Mark_K5LXP]

SoC is dependent on load. Most SoC charts are based on no load conditions. If you're using the battery at all, then the chart values don't apply. I know that doesn't offer an explicit answer to the question "how much is left?" but technically the only correct answer is "it depends". First order answer, what the terminal voltage is at a given current can reveal a fairly good number of where the battery is at. To gain greater accuracy requires some history and battery characterics. Enter the battery monitor. They keep track of the minutia and crunch the variables real time. So if 'close' is good enough then a glance of voltage *and* current can reveal a useful number. Down to the minute or watt hour remaining takes data and calculation.

Mark B.
Albuquerque, NM

 

[John From Detroit]

As a sanity check you can test the integrity of all the connections quickly and easily by loading (or charging) with a nominal current (say 10-20A) and testing for voltage drop as you did to discover your open connection. A 'good' connection will have only a handful mV of drop, and you will see right away if one is an outlyer before it goes thermal or opens up. If you're extra OCD you can log the measurements for future comparison.

Had a car that would not start.. Touched the battery terminals with a dampened finger

One cold. One hot.. Cleaned the hot one, varoom.

 

[Mark_K5LXP]

This'll cure what ails ya. The fact it comes up in a search shows it's not uncommon.

Mark B.
Albuquerque, NM

 

[DonTom]

SoC is dependent on load. Most SoC charts are based on no load conditions.

True, but I want it to show for the normal load in this RV. So I calibrate if for 100% SOC when it is drawing very little charge current from the genny or from the solar while it is charging.

The main thing I want to know is stuff such as when to turn the genny off when using it to charge up the batts. Right now, my stock lead acid house batteries are still accepting 70 watts / 5.02 amps (13.94 VDC) from my solar panels, showing 100% SOC. When the current gets down a bit lower, I will recalibrate for 100%.

BTW, I am going to soon change out the two lead acid 6VDC batteries for a single 12V LifePo4 battery, since the L/As are now around five years old. I will need to make some minor modifications to do such.

-Don- Sac Pass, NV