Don't Blind Charge! (IBS)

[carlrx7]

I did not know this! Blind charging is hooking up a battery charger directly to your battery. I made this mistake the first time I charged, then I noticed the Sensor on the negative post and did some research.

low and behold... RAM TSB 384

-cheers

 

[flan]

Would this be the same for a battery tender for vehicles that sit over the winter? What exact negative consequences does this cause?

 

[RV_Goose]

Interesting. I learned something!

 

[jadmt]

seems like this is only for stop start vehicles.

 

[carlrx7]

Would this be the same for a battery tender for vehicles that sit over the winter? What exact negative consequences does this cause?

Yes, but all you need to do is make sure the negative is grounded to the body, vs directly to the battery. The sensor will not see the additional charge you are putting in the battery and could read to a false state of charge reporting for the battery.

seems like this is only for stop start vehicles.

Correct, part of the TSB mentions the Start/Stop, but the IBS and state of charge accuracy still applies to our trucks.

 

[Distillusion]

Nice find.

 

[flan]

Yes, but all you need to do is make sure the negative is grounded to the body, vs directly to the battery. The sensor will not see the additional charge you are putting in the battery and could read to a false state of charge reporting for the battery.


Correct, part of the TSB mentions the Start/Stop, but the IBS and state of charge accuracy still applies to our trucks.

I charged all last winter without an issue, I guess it can’t hurt to switch out the negative. If anything it will give me something to do tomorrow haha!

 

[Nick]

Good ino thanks for sharing .f

 

[jadmt]

I did not know this! Blind charging is hooking up a battery charger directly to your battery. I made this mistake the first time I charged, then I noticed the Sensor on the negative post and did some research.

low and behold... RAM TSB 384

-cheers

do you know if this IBS device has any affect on running 12V directly off the battery? I have an ARB fridge and my last vehicle did not have IBS. It has a fused harness that uses 10g wire and in the past I just ran straight off both positive and negative posts. thanks

 

[carlrx7]

do you know if this IBS device has any affect on running 12V directly off the battery? I have an ARB fridge and my last vehicle did not have IBS. It has a fused harness that uses 10g wire and in the past I just ran straight off both positive and negative posts. thanks

This would be in another word, blind 'dis'charging, just move the ground to the frame or other side of the ibs sensor.

 

[jadmt]

This would be in another word, blind 'dis'charging, just move the ground to the frame or other side of the ibs sensor.

is blind discharging any different than regular discharging? Is that even a thing? thanks

 

[jsalbre]

is blind discharging any different than regular discharging? Is that even a thing? thanks

Yes. If you connect the circuit negative directly to the battery negative post then the shunt cants see the flow and doesn’t know what the draw is.

On modern vehicles always connect to the posts that other cables are connected to, never directly to the battery posts.

 

[lovegolf44]

I have my tender connected to the positive terminal of the battery and the neg clamp on the ground screw connected to the frame.. This assures both batteries are being trickle-charged efficiently.

 

[jsalbre]

I have my tender connected to the positive terminal of the battery and the neg clamp on the ground screw connected to the frame.. This assures both batteries are being trickle-charged efficiently.

How are the batteries connected to each other?

If you’re only connected directly to one battery then it’s likely that your tender is giving more power to the battery with a lower resistance overall path.

 

[lovegolf44]

How are the batteries connected to each other?

If you’re only connected directly to one battery then it’s likely that your tender is giving more power to the battery with a lower resistance overall path.

I didn't think I was connecting directly to one battery by using the chassis ground. My understanding is the batteries are in parallel so I assume both batteries should be charging by using the chassis ground.

 

[jsalbre]

I didn't think I was connecting directly to one battery by using the chassis ground. My understanding is the batteries are in parallel so I assume both batteries should be charging by using the chassis ground.

You said you were connecting to the positive post of the battery.

 

[lovegolf44]

You said you were connecting to the positive post of the battery.

Correct. I have the positive charging clamp on the positive terminal of one battery (driver's side) and the negative charging clamp on the chassis ground in the engine area. That charges both batteries because the batteries are in parallel and grounded to the chassis. I confirmed this with Deltran technical support to make sure.

 

[jsalbre]

Correct. I have the positive charging clamp on the positive terminal of one battery (driver's side) and the negative charging clamp on the chassis ground in the engine area. That charges both batteries because the batteries are in parallel and grounded to the chassis. I confirmed this with Deltran technical support to make sure.

Correct, it is technically charging them both, but due to different paths to each and the different resistance of those paths the batteries are likely not charging to the same amount. The one that you have the cable attached directly to is going to have a lower resistance path and thus charge at a higher rate than the other (unless the path from the ground stud to that battery is significantly higher resistance than the path from the ground stud to the other battery).

You’d have to ohm out the path to tell for sure what the difference is.

I don’t know if it’s enough to matter, but it’s there.

 

[Distillusion]

Batteries do have a maximum charge level. Even if both are charging at slightly different speeds due to small resistances in wiring and connections, they will both reach maximum charge easily enough, just at slightly different times. If you leave the charger on long enough, both get fully charged. I wouldn't expect to see much difference in resistance at all if the connections and wiring are correct.