Are the batteries really isolated during ESS stops?

[ShadowsPapa]

Anyone care to guess how much charge a cold start takes? Amp-hours or percentage of battery capacity, your choice.

On a 80 degree engine with clean injectors and low miles, or a 50 degree engine with 100,000 miles and worn plugs and dirty injectors?

Some will depend on the battery condition

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[Flanders]

On a 80 degree engine with clean injectors and low miles, or a 50 degree engine with 100,000 miles and worn plugs and dirty injectors?

Some will depend on the battery condition

A 2023 3.6L with 7000 miles, clean injectors and plugs, well maintained batteries in a climate similar to that of Fish Lake Valley NV in early November.

 

[ShadowsPapa]

A 2023 3.6L with 7000 miles, clean injectors and plugs, well maintained batteries in a climate similar to that of Fish Lake Valley NV in early November.

I can't wrap my head around math tonight - incision pain and throbbing head, otherwise it might be fun to see how far off I can get.
I KNOW you know.

 

[Flanders]

I can't wrap my head around math tonight - incision pain and throbbing head, otherwise it might be fun to see how far off I can get.
I KNOW you know.

That's too bad, I'm sorry to hear it.

I did take a measurement. My first thought was, did I mess up the units?

 

[jebiruph]

I don't think this IBS SOC information is correct. This is from the IBS manufacturers website and describes how the IBS (called EBS by the manufacturer) uses the shunt connected to the battery to measure current, so it's calculations are based on the battery it's connected to. Can you explain how the IBS with it's shunt connected to the main battery is able to report anything related to the SOC of the aux battery?

edit: Maybe this explains why the aux battery negative cable is connected to the main battery negative terminal where the IBS is installed. Maybe the thought was this would allow the IBS to monitor both batteries. Unfortunately, that's not the way it works. The IBS only monitors main battery current unless someone can explain otherwise.

 

[Flanders]

Anyone care to guess how much charge a cold start takes? Amp-hours or percentage of battery capacity, your choice.

No takers? Seems like the sort of thing a person should know.

83mAh, 0.1% of capacity, passed through the main ground wire from the moment I opened the door to get in to the time the alternator began recharging the battery.

It's clear on the trace when I opened the door and got in, just after 1 second. Cranking started at 5 seconds and took about 0.6 seconds. There was another 3 seconds of load on the battery before the alternator was supplying charging current.

Yes, there's likely a few percent error in the measurement. No, I don't have to factor in Peukert's Law. An amp-hour is an amp-hour.

 

[J Sierra]

Starter current

 

[Flanders]

Another cold start trace showing shunt voltage (yellow) and discharge (red). This taken on an RC filter with 33ms time constant across the MAIN- to chassis ground wire.

It shows that the discharge from starting is returned to the batteries in about 25s, when the red trace crosses zero.

Multiply shunt voltage by 2.5A/mV to get current.

 

[ShadowsPapa]

These really don't take much from the batteries to start. Even less for an ESS restart..

 

[Flanders]

These really don't take much from the batteries to start. Even less for an ESS restart..

They don't take much to sit idle either. Our Honda draws more, and it has about one-third of the battery capacity.

I really don't understand why so many people end up with chronically (and terminally) undercharged batteries.

 

[ShadowsPapa]

They don't take much to sit idle either. Our Honda draws more, and it has about one-third of the battery capacity.

I really don't understand why so many people end up with chronically (and terminally) undercharged batteries.

If you were closer I'd hand you the keys to my JT and turn you loose taking all sorts of measurements, but looks like I'm on very restricted duty for weeks more - I thought my head hurt a lot more this time and my wife said - there's a whole lot more incision and they had to remove the coil of wires up there from the scar tissue and where things had started to grow around the wires so they could clean it up.

I agree - it's odd that even on mine, the batteries end up so low after sitting. If I was a younger person in better shape physically and mentally, I'd be so all over this!

 

[J Sierra]

New scope C is powered, so it works with battery pack. Now I can drive with the scope. I will get ESS start with starter current.

 

[J Sierra]

N1 yellow, N2 green, PCR blue, starter relay purple.

Next blue is run#1 relay k13

Next blue is run/acc#1 relay k14

 

[ShadowsPapa]

Man, that is dirty

 

[J Sierra]

Yes, lots of noise when starting. This scope makes it easy to transfer the image.

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