ESS Dual Battery System Operation

[jeepin48]

Yes, that graph was with engine off maintainer on. Below is maintainer off for 2 weeks, as you can see, there is a gradual creep downward despite several driving events. It would be interesting to see the data from a true 'daily driver'.

WOW! Thanks Mike. That confirms how significant the parasitic draw actually is. In 3 days you went from 12.7-12.4V ish. At that rate you would be at 12V in 7 days and 10V in 27 days where it would really piss the computer off.

It is no wonder why there are so many claimed "bad batteries". If you park these things for any amount of time the batteries will rot away.

If anyone is curious if their driving habits are killing their batteries they should check the battery voltage before they start the engine. If you are below 12.4V then you should probably use a battery maintainer / tender.

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[jebiruph]

I am in the process of installing a S-Tech auxiliary switch system. I disconnected the top battery Neg term and the fender neg terminal thinking I was disconnecting the aux battery. After taking the center dash panels off, installing the switch panel then reinstalling the center panels, the JT would not start. I checked the fender connection and the top neg terminal. I did let it sit for 24hours with the batteries disconnected. Now I noticed two large cables at the fender ground. The picture at the beginning of this thread shows the aux neg going to the main neg and then to the fender ground. Is this second cable on the fender ground my aux battery neg.? I am charging (1 amp trickle) the top battery with everything I had disconnected hooked up. I was reading 12.2v before I started charging. next time I will check for power after disconnecting. At this point, no other electrical devices have been installed. Still waiting for the circuit breaker for the S-Tech sys.

Both batteries are grounded to the body through one cable from the main battery negative. That second fender ground cable is not for either battery.

 

[Lost1wing]

Both batteries are grounded to the body through one cable from the main battery negative. That second fender ground cable is not for either battery.

So now I don't understand why it would not start. No faults on the dash, showing 12.2v, lights were nice and bright yet not even a click on the start solenoid. Volts stayed at 12.2v during a start attempt.

After one hour on a trickle charger, it started normally. Should I have just waited a few minutes after connecting the battery to try to start? IBS not upto speed yet? Failed test of the Aux battery? No faults on the dash though.

After driving it around a while I shut it off and put the trickle charger back on. Three hours later, the charger was in maintenance mode. The battery probably was not dead. Next week I will disconnect it again for a while to finish my aux switch installation.

Thanks

 

[ShadowsPapa]

12.2 volts is like 20 to 35% charge if i recall my chart from GM. 12.2 volts is nothing. You need 12.6 to 12.8 on AGM batteries. I consider 12.2 to be bad or all but dead.
Only an hour on trickle?? Charge overnight.

 

[Lost1wing]

12.2 volts is like 20 to 35% charge if i recall my chart from GM. 12.2 volts is nothing. You need 12.6 to 12.8 on AGM batteries. I consider 12.2 to be bad or all but dead.
Only an hour on trickle?? Charge overnight.

I checked it this morning. Voltage is holding at 12.6. I will check it again tomorrow morning and see if it drops any. I Don't plan on using it this weekend. I may just see what it does for the next few days.

 

[Lost1wing]

I checked it this morning. Voltage is holding at 12.6. I will check it again tomorrow morning and see if it drops any. I Don't plan on using it this weekend. I may just see what it does for the next few days.

I checked the battery voltage for several days. At day 7 it was down to 12.2v, yet it started right up. I put a battery tender on it overnight. When I got up this morning the battery tender was in maintenance mode. I drove the jeep around for 30 min. Stop/start disabled, battery charging.

Any harm in disconnecting the n1 and n2 terminals to measure each battery isolated?

How do you reset the IBS?

 

[ShadowsPapa]

I checked the battery voltage for several days. At day 7 it was down to 12.2v, yet it started right up. I put a battery tender on it overnight. When I got up this morning the battery tender was in maintenance mode. I drove the jeep around for 30 min. Stop/start disabled, battery charging.

Any harm in disconnecting the n1 and n2 terminals to measure each battery isolated?

How do you reset the IBS?

Did you measure battery voltage after charging it? Odd that a tender would have a low battery fully charged and in maintenance mode that fast, but at 12.2 volts it's not dead, just about 40%. I never have that luck, it usually takes 24 hours to get a battery at about 12 volts up to "maintenance" in my shop. (old school batteries.....)
I'd be curious about the actual battery voltage after charging overnight - charger disconnected, surface charge drained. Might be looking at battery issues. I'd also check them individually, not as a connected pair as that's probably how they are being charged, making me even more curious about having them at 12.2, charging only over night and then being "fully charged".
Voltage test after charging is the only decent indicator.......
Is your battery charger listed for AGM batteries? Most will work, but.........

 

[Lost1wing]

Did you measure battery voltage after charging it? Odd that a tender would have a low battery fully charged and in maintenance mode that fast, but at 12.2 volts it's not dead, just about 40%. I never have that luck, it usually takes 24 hours to get a battery at about 12 volts up to "maintenance" in my shop. (old school batteries.....)
I'd be curious about the actual battery voltage after charging overnight - charger disconnected, surface charge drained. Might be looking at battery issues. I'd also check them individually, not as a connected pair as that's probably how they are being charged, making me even more curious about having them at 12.2, charging only over night and then being "fully charged".
Voltage test after charging is the only decent indicator.......
Is your battery charger listed for AGM batteries? Most will work, but.........

The dash said 12.8v before starting it this morning. My fluke said 12.9v. The battery minder plus is what I use overnight on all my equipment. It had restored many batteries but never the type in the jeep.

Not knowing how to reset the IBS. I disconnected it for 1 minute. I plugged it back in and went for a 10 minute ride. Battery charging msg went away and stop/start worked. I got a not ready msg for 30 seconds and then it went away. Dash voltage down to 14.1 with the engine running. When the battery voltage being supplied to the battery was at 14.6 is when the battery charging msg was on.

 

[ShadowsPapa]

Very interesting. Then your charger did indeed do exactly as it should, and the 12.6+ reading (in your case 12.8) would indicate they took a charge and were exactly where they should be.
If your Fluke was right at the batteries it's not dealing with any voltage drop at all so would be most accurate but then 12.8 on the dash could well be 12.85 so consider them the same really.

Since mine has been driven for hours and still says "battery charging" I suspect I may have the issue with IFS kind of working but not perfectly set. Come warmer weather, like 40s or better, it will be fine, but when it's cold I can drive this thing for 60 minutes or more, and it will indicate batteries charging. Since I'm bound to go in in a few days for other service work, I'll chat with 'em about it.

 

[slim chance]

i have read post after post about message

it will indicate batteries charging

... where is everybody but me seeing these messages ... my Nacho stop/start did not work, dealer tested both batteries, dead aux battery, took a week to get new and replace .. NEVER did i see any messages about stop/stop not working ... slso my wife's HA sat for over a week, with VERY cold temps, it took over an hour of driving before stop/start began working as it should ... no messages on that either .... what/were is this message supposed to display????

 

[ArmyMP]

i have read post after post about message
... where is everybody but me seeing these messages ... my Nacho stop/start did not work, dealer tested both batteries, dead aux battery, took a week to get new and replace .. NEVER did i see any messages about stop/stop not working ... slso my wife's HA sat for over a week, with VERY cold temps, it took over an hour of driving before stop/start began working as it should ... no messages on that either .... what/were is this message supposed to display????

Shows up under the dash menus. Stop start has its own menu.

 

[ShadowsPapa]

i have read post after post about message
... where is everybody but me seeing these messages ... my Nacho stop/start did not work, dealer tested both batteries, dead aux battery, took a week to get new and replace .. NEVER did i see any messages about stop/stop not working ... slso my wife's HA sat for over a week, with VERY cold temps, it took over an hour of driving before stop/start began working as it should ... no messages on that either .... what/were is this message supposed to display????

Scroll pages up and down with the left up/down arrow buttons on the steering wheel. I think it's about 2 pages "down" from where trips and mpg is shown.
Go ahead and scroll those pages up and down and on some pages, you can go left and right and see even more information. There's a ton you can do with that display.

 

[slim chance]

you mean to tell me everybody is driving around with that display, i kinda figured it out that the battery was low causing the stop/start to not work .... i came from 2019 Ram 1500 Larime (wife's) and 2019 Ram 2500 BH (still have it) ... there has never been anything saved in messages in either of those, even when the trottle stuck wide open (that 392 can really go fast, a real thrill, kind of always suprised the dealers but not me, just another Uconnect error, so i didn't bother to look on the JT (either one)

 

[ShadowsPapa]

you mean to tell me everybody is driving around with that display, i kinda figured it out that the battery was low causing the stop/start to not work .... i came from 2019 Ram 1500 Larime (wife's) and 2019 Ram 2500 BH (still have it) ... there has never been anything saved in messages in either of those, even when the trottle stuck wide open (that 392 can really go fast, a real thrill, kind of always suprised the dealers but not me, just another Uconnect error, so i didn't bother to look on the JT (either one)

What's uconnect got to do with anything?? This is the system display in the cluster, and uconnect has nothing to do with engine controls like throttle, battery charging, etc.
uconnect is an interface and doesn't control the engine or throttle or display the state of battery charge/voltage, ESS, transmission temperature or whatever.
If your throttle stuck - it had nothing to do with uconnect. (that's not where messages come from anyway)

No, we're not driving around with that display. I only scroll to it when I am "wondering". Geesh LOL. It's so simply to use a thumb and hit those buttons and scroll to what you want to see. Now and then I flip pages to see tire pressure, battery state for ESS, voltage, all that other stuff. It's there, it's easy, thumb controls. I like to know what's going on with my vehicles at any given time.
Nice to diagnose when things aren't working, instead of guessing. Using that and other things I now know I need to have some things checked out as stuff isn't really quite what it should be. I like preventing trouble and troubleshooting and not waiting or guessing.
This isn't a saved message, its a CURRENT state of affairs. Since the ESS stuff is transient, there won't be any saved or stored messages. That display is all live stuff like oil temperature, transmission temperature, whatever.
I don't like "kind of figuring out" - doesn't help at all when you try to resolve issues - solid reports, facts help. When it tells you directly "ESS not ready, battery charging" and it does this for an hour, it's not "Battery low" causing it - it's battery never charging fully or the IFS is wrong.
And not ever fully charging a battery while driving leads to short battery life.

 

[slim chance]

i guess my mom was right, IF you don't have anything nice to say, then keep your mouth shut

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