Battery discharge at rest

[THAW]

Hello,

thanks everyone for the responses.
I have new observations. First, the SOC drops to 88% as I last observed probably about an hour after parking, but it does not drop lower even after 24 hours.
The car still has Start/Stop ready, which is new to me, because it has not worked since it was new. According to the measurements, my battery manages to charge during short drives and I park in the evening with 100%.
As for the meters, they are connected directly to the battery, they have a consumption of 1.5mAh, BT4.2.
I do not know exactly how those SOC meters measure. I can measure the voltage with a multimeter and that is accurate and I can also measure the battery temperature and this measurement is also accurate. I am quite surprised that the battery temperature rose to 65 degrees Celsius during the day at an outside temperature of 30 degrees, which surprised me. That was the highest temperature value, which was reached in the sun and with a longer stand, it drops quite significantly, with air cooling down to values around 40 at an outside temperature of 30.
According to observations, the main battery is primarily charged, but not to full capacity, the difference between AUX and main was never more than 10%.
Special thanks to @THAW for letting me check Live data in JScan.

What device is associated with the app you're using?

And how did JScan SOC for the main battery compare to the SOC reported by the app?

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[Mguy]

@Mguy Sounds like the theorist slept through the lectures on filter design.

I don't think he took that course. He was probably in an electromagnetic theory class, day dreaming unsolvable problems to later dump on his engineering buddies at the bar.

 

[Mguy]

The Body Controller tracks about 15 IBS metrics (and about double that including status/error conditions). Importantly, it tracks real-time current and lifetime charge received/released.

OK (whatever "lifetime charge accepted/released" is). But what Jeep system, other than those ancillary to operation, actually uses SOC data, and how?

 

[mister flanders]

I don't think he took that course.

That would explain it.

It would be foolish of him, though not out of character for that type, to insist that no easy and obvious solution exists to the problem of averaging a rapidly varying signal.

Most freshmen EE's come up with the following on their own:

A big capacitor in parallel with the shunt resistor limits dV/dt while not changing the integral of V with respect to t.

 

[mister flanders]

A couple of additional thoughts:

1. Some of the numbers reported by JScan are not scaled correctly. Some appear to be nonsense. I've run into this a few times.

2. I saw greatly increased draw on the battery while using JScan to set my tire size.

Regrettably I didn't make any notes and I don't remember the specifics.

For fun, this was the situation after parking my JT overnight, moving it into the garage this AM, opening the hood and letting it sit another hour, then charging at 13.8V for 4 hours. There are two devices reporting charge delivered. All three show current:

The 1.3Ah delivered includes whatever the Jeep drew since it was parked yesterday, plus the discharge of a cold start, plus the draw of the vehicle since shutting it off again, minus whatever the alternator managed to charge during the minute it ran.

The battery is almost fully charged at this point. The current would eventually drop to 30-40mA at 13.8V if I left it on.

 

[THAW]

(whatever "lifetime charge accepted/released" is).

Intelligent Battery Sensor Lifetime Charge Received (AmpHrs) and Intelligent Battery Sensor Lifetime Charge Released (AmpHrs), are exactly what you've been debating: cumulative measurements of current (through the IBS) in and out of the CR[an]K battery.

 

[Terrymo]

Intelligent Battery Sensor Lifetime Charge Received (AmpHrs) and Intelligent Battery Sensor Lifetime Charge Released (AmpHrs), are exactly what you've been debating: cumulative measurements of current (through the IBS) in and out of the CR[an]K battery.

So many CR[an]K[y] people in the battery forum

 

[THAW]

For fun, this was the situation after parking my JT overnight, moving it into the garage this AM, opening the hood and letting it sit another hour, then charging at 13.8V for 4 hours. There are two devices reporting charge delivered. All three show current:

...

The battery is almost fully charged at this point. The current would eventually drop to 30-40mA at 13.8V if I left it on.

Why 13.8V? Isn't that too low for end-stage absorption phase AGM charging?

 

[Zandcwhite]

Does it actually go dead after 2 days or is it a high initial draw combined with a less than accurate measurement as others speculated? It's only a problem if it's actually a problem. Feels like analysis paralysis.

 

[Mguy]

That would explain it.

It would be foolish of him, though not out of character for that type, to insist that no easy and obvious solution exists to the problem of averaging a rapidly varying signal.

Most freshmen EE's come up with the following on their own:

A big capacitor in parallel with the shunt resistor limits dV/dt while not changing the integral of V with respect to t.

So many CR[an]K[y] people in the battery forum

Incomplete response.

Too many CR[an]Ks

 

[Mguy]

Intelligent Battery Sensor Lifetime Charge Received (AmpHrs) and Intelligent Battery Sensor Lifetime Charge Released (AmpHrs), are exactly what you've been debating: cumulative measurements of current (through the IBS) in and out of the CR[an]K battery.

Fine, but where's the beef?

Assuming data not limited to "lifetime" cumulation, what's Jeep doing with it? Do us owners have to figure out how real SOC should be used?

 

[Mguy]

That would explain it.

It would be foolish of him, though not out of character for that type, to insist that no easy and obvious solution exists to the problem of averaging a rapidly varying signal.

Most freshmen EE's come up with the following on their own:

A big capacitor in parallel with the shunt resistor limits dV/dt while not changing the integral of V with respect to t.

It's truly wonderful that electrical engineering has progressed to the point where even freshman can solve the "problem of averaging a rapidly varying signal," although "rapidly" is a bit easy for what's going on. Kids eat ice cream "rapidly." Even lazy electrons are moving near instantly.

So SOC data works for freshman level engineering, but when will EE problem solvers get around to preventing explosions while charging? It's still going on, even for lead-acids.

 

[Mguy]

Does it actually go dead after 2 days or is it a high initial draw combined with a less than accurate measurement as others speculated? It's only a problem if it's actually a problem. Feels like analysis paralysis.

Important point. @Cartman, as the OP, should have his issue(s) addressed.

 

[mister flanders]

Why 13.8V? Isn't that too low for end-stage absorption phase AGM charging?

13.8V is enough to fully charge an AGM. It's safe(ish) for a few hours at high temperatures and for much longer at lower temperatures.

A typical smart charger terminates 14.4V absorption when current falls below about 500mA, or after a couple of hours, whichever comes first, to avoid damage due to overcharge.

Just to see, I pulled mine up to 14.4V this AM. Current fell below 500mA in less than 10 seconds and was just over 100mA 10 minutes later. It would eventually fall below 80mA at 14.4V. The battery had been held at 13.4V overnight.

 

[Cartman]

What device is associated with the app you're using?

And how did JScan SOC for the main battery compare to the SOC reported by the app?

I'm away from home. Hopefully I'll get to the car over the weekend.

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