Question on IBS when trickle charging over a few days.

[kb5zcr]

Howdy all,
I have been trickle charging (charger set on 2 amps) for two+ days via the 7-pin trailer plug.
Here is my question: Does the IBS still keep track of the amps/charge added to the battery even though the truck is asleep?
I'm wondering if after three days of trickle charging and the battery now fully charged, will the IBS know this or still think the battery is at the same state of charge it was when I parked it?

Thanks for your expert opinion.

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[MaximusTX]

Howdy all,
I have been trickle charging (charger set on 2 amps) for two+ days via the 7-pin trailer plug.
Here is my question: Does the IBS still keep track of the amps/charge added to the battery even though the truck is asleep?
I'm wondering if after three days of trickle charging and the battery now fully charged, will the IBS know this or still think the battery is at the same state of charge it was when I parked it?

Thanks for your expert opinion.

I could be wrong but from my understanding as long as the charge is going thru the IBS which I believe it should be in this case but not entirely sure it should know. When charging the battery directly if you connect directly to the battery and skip the IBS it wouldn't know unless you reset it. Again, I have limited knowledge about the IBS and this is just my understanding of it.

 

[Stuntman Mike]

Here is my question: Does the IBS still keep track of the amps/charge added to the battery even though the truck is asleep?

I would say no.

But as far as I understood the IBS functality, it will calculate the status of charge and status of health after each start of the vehicle and should therefore have the correct parameters after restart.

My car is, as long as it's sitting in the garage permanently hooked to the tricle charger and up to now I never had any issues.

 

[SoK66]

When charging the battery Jeep wants the positive charger cable attached to the battery, but the negative charger cable attached either to an unpainted body stud, or the engine block. I’ve read this same instruction set before regarding Ford’s version of the IBS.

 

[ssrlewis]

Whether attached to charger or not, I still have to deal with my IBS everyday.


Steve

 

[Hemy5587]

Whether attached to charger or not, I still have to deal with my IBS everyday.


Steve

Glad it wasn't just me thinking it when I was reading through this thread . When doing my monthly charge up of my batteries I have always hooked to positive and negative above the IBS vs their recommendation of a ground on the block and/or body, I haven't messed anything up yet that I am aware of. However my set up is the classic pop the hood and attach the charger vs OP's 7 pin set up, so I guess the question is how do you have it wired up? If through the IBS then if should recognize the state/ charge.

 

[SoK66]

I had a moment this AM to check for an “unpainted” stud under the hood. Sure enough, where the ground cables mount to body there is a separate, unpainted stud available for the charger ground. I’ve run my conventional charger on the JT, but not knowing the IBS needs, did so conventionally, using the pos & neg terminals on the battery. No apparent harm done but the IBS probably wasn’t pleased.

 

[JTdiRtyD]

Here is my question: Does the IBS still keep track of the amps/charge added to the battery even though the truck is asleep?

Yes. The monitoring of amps in and amps out is measured at the negative terminal. The item pointed to in red is the sensor, everything that comes out of or goes into the battery runs through this. It is always monitoring even when truck is asleep. If it didn't monitor when the truck was asleep, you could have parasitic draw and it wouldn't know how much charge to input back into the battery and could over/under charge and ruin the battery/cause fires/etc. This is why it's important to always connect anything to the top side of this battery connector and never at the post side.

Also, ignore the years in the photo, thats for aux deletes on a diesel.

 

[kb5zcr]

so I guess the question is how do you have it wired up? If through the IBS then if should recognize the state/ charge.

There is power available at the 7-pin trailer plug all the time, I have my charger connected to the pos and ground via this plug (make connecting the charger easy).
From reading JTdirtyD's response, it looks like the IBS can sense this and I'm good to go.

 

[kb5zcr]

Yes. The monitoring of amps in and amps out is measured at the negative terminal. The item pointed to in red is the sensor, everything that comes out of or goes into the battery runs through this. It is always monitoring even when truck is asleep. If it didn't monitor when the truck was asleep, you could have parasitic draw and it wouldn't know how much charge to input back into the battery and could over/under charge and ruin the battery/cause fires/etc. This is why it's important to always connect anything to the top side of this battery connector and never at the post side.

Also, ignore the years in the photo, thats for aux deletes on a diesel.

Thank you sir, this tells me exactly what I need to know.
I appreciate all the help from the forum.

 

[Waldomountainman]

Yes. The monitoring of amps in and amps out is measured at the negative terminal. The item pointed to in red is the sensor, everything that comes out of or goes into the battery runs through this. It is always monitoring even when truck is asleep. If it didn't monitor when the truck was asleep, you could have parasitic draw and it wouldn't know how much charge to input back into the battery and could over/under charge and ruin the battery/cause fires/etc. This is why it's important to always connect anything to the top side of this battery connector and never at the post side.

Also, ignore the years in the photo, thats for aux deletes on a diesel.

 

[Waldomountainman]

Can you clarify rhe last three sentences in this post, not computing.

 

[SoK66]

I tested the charging recommendation last night. I put the charger positive on the positive battery clamp, put the charger negative on the unpainted stud at the body ground. Let it charge overnight. Battery reading before was 12.0v. State of charge this AM was 12.7v. Beforehand driving charge rate was 14.5v fairly constantly. Today after charging per the TSB the charge rate was 12.8v, but occasionally rising to 13.8v.

 

[JTdiRtyD]

Can you clarify rhe last three sentences in this post, not computing.

The black piece in the photo is a shunt. It measures amps coming out of the battery by systems using power, and it measures amps going back into the battery from the charging system.

To put it simply, it acts as a counter with simple math. Lets say your battery has 100ah (amp hours) of power. If something is using 10amps (measured per hour), then over the course of 1 hour the shunt will measure 10 amps removed from the battery, so the IBS knows your battery now has 90 amps remaining. Now put a 10amp charger on it (again, measured per hour), over the next hour it sees 10 amps going back into the battery, so its "count" is back to 100.

If you connect something to the battery side of the shunt, then the current isn't passing through it for it to measure and the IBS doesn't know how much power has been drawn from the battery. This can lead to a improperly charged battery because the counter is now off. Thats why it's important to always connect wires to the top side of the shunt, not the battery side. Everything power related has to travel through the shunt in order for the IBS system to work properly.

Theres more to it than that, but thats the simple version of how battery monitoring systems work.

 

[Radio Guy]

The black piece in the photo is a shunt. It measures amps coming out of the battery by systems using power, and it measures amps going back into the battery from the charging system.

To put it simply, it acts as a counter with simple math. Lets say your battery has 100ah (amp hours) of power. If something is using 10amps (measured per hour), then over the course of 1 hour the shunt will measure 10 amps removed from the battery, so the IBS knows your battery now has 90 amps remaining. Now put a 10amp charger on it (again, measured per hour), over the next hour it sees 10 amps going back into the battery, so its "count" is back to 100.

If you connect something to the battery side of the shunt, then the current isn't passing through it for it to measure and the IBS doesn't know how much power has been drawn from the battery. This can lead to a improperly charged battery because the counter is now off. Thats why it's important to always connect wires to the top side of the shunt, not the battery side. Everything power related has to travel through the shunt in order for the IBS system to work properly.

Theres more to it than that, but thats the simple version of how battery monitoring systems work.

Is this all stated by Jeep or is it a theory? I don't know the facts about IBS but I believe the IBS does not "count" how much current goes out vs in and instead when you start the vehicle it comes alive and measures battery voltage and charge current to know the approximate battery state of charge at that point in time. The amount of current out vs in is not the same as it takes a charge about 1.5X what you take out to charge to 100% and that will vary with battery type and age which the IBS is not aware of.

And another thing, some chargers are designed to read battery voltage, charging current and when to ramp charging up or down measured at the battery clamps and the factory charger cable resistance is taken under consideration. When you plug a charger into the trailer connector at the rear bumper your adding 15-20ft of unknown wire that goes who knows where. Some chargers may over or under charge due to the added resistance of the trailer wiring. With that said I have been connecting a 50w solar panel and MPPT charger to my trailer connector since I got my JT in 2021 because it doesn't get driven much and if parked for several weeks the battery may not be able to start the vehicle. The trailer connection has worked ok for me for charging but maybe not for everyone.

I just removed and deleted the aux battery last week and replaced the main battery with a 94 series Odyssey and when I measured my old batteries with a complex meter that reads internal resistance and other things, it claims the battery is still about 80% of new after 4 1/2 years. I suspect keeping it on the solar charger has extended its life quite a bit.

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