BMS Battery Setting

[Ohwell]

When it comes time to replace the battery in my truck, the plan is to replace the H6 with an H7. I know there is a setting in Forscan for battery type and size. What does the charging system do differently between an H6 AGM and an H7 AGM battery?

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[Superspirit]

It charges the battery to its capacity percentage. The H7 has a higher capacity than the H6. So the BMS will look for the percentage it is set to charge to. Another words if it is set to 75% of a 600 amp battery it will charge to 450 amps. If it is set to 75% of a 700 amp battery it will charge 525 amps. Not sure I listed the amps for corresponding batteries correctly but the theory is correct.
I have mine set to charge to 90% of the H7 I installed in mine.

 

[Ohwell]

So what would happen if you left the SOC at 75 and changed the battery from an H6 to an H7 and still left the H6 battery in the truck?

 

[airline tech]

So what would happen if you left the SOC at 75 and changed the battery from an H6 to an H7 and still left the H6 battery in the truck?

From my deep dives into this as well as @TJC - Programming H6 to H7 Battery (Type) and keeping the H6 battery installed.

BMS Will (Assume)

1. More reserve than actually exists
2. Battery can support more load than it should
3. (Low Voltage) issues - (Load Shedding) will wait longer to enable

The BMS system uses coulomb counting, and the Amp Hour (Rating) of the battery is a vital input parameter for the charging data,

The H6 Battery is programmed for 70 Amp Hours and the H7 is programmed for 80 Amp Hours

Summary - Changing from H6 to H7 - As-Built only will not force a better charge, it will only alter how to BMS system interprets the actual battery capacity.

1. Meaning the BMS system will think the SOC is better than it actually is and the SOC input is the most important aspect of the BMS system and when it starts load shedding

This is where - bumping the actual SOC Target comes into play, force it well above the minimum thresholds that generate the issues (actual charging targets) vs lying to the BCM with only a battery type change and keeping the lower rated battery installed.

On a side note - Battery Size Change (As-Builts)
BCM - 726-04-01
(XL/XLT) - 0101-0000-093D
(Lariat) - 0201-0000-093E

x1xx-xxxx-xxxx - (1) equals H6 - 70 Amp Hour
x2xx-xxxx-xxxx -(2) equals H7 - 80 Amp Hour

The easy menus make it confusing (in the wording) along the line as far as the size, this is the actual line that is changed from that easy menu, and it changes the 1 to a 2.

 

[harringtondav]

Just a heads up. I recently replaced my battery. I searched for AGM batteries for a 2019 Ranger. Two choices came up. I went with the higher CCA and reserve. I didn't know the group size for OEM.
The battery size I got fit into the tray fine and worked w/o issues. But the insulating blanket for the battery was too small. I managed to wrap most of the battery with a gap on the engine side.

 

[Ohwell]

From my deep dives into this as well as @TJC - Programming H6 to H7 Battery (Type) and keeping the H6 battery installed.

BMS Will (Assume)

1. More reserve than actually exists
2. Battery can support more load than it should
3. (Low Voltage) issues - (Load Shedding) will wait longer to enable

The BMS system uses coulomb counting, and the Amp Hour (Rating) of the battery is a vital input parameter for the charging data,

The H6 Battery is programmed for 70 Amp Hours and the H7 is programmed for 80 Amp Hours

Summary - Changing from H6 to H7 - As-Built only will not force a better charge, it will only alter how to BMS system interprets the actual battery capacity.

1. Meaning the BMS system will think the SOC is better than it actually is and the SOC input is the most important aspect of the BMS system and when it starts load shedding

This is where - bumping the actual SOC Target comes into play, force it well above the minimum thresholds that generate the issues (actual charging targets) vs lying to the BCM with only a battery type change and keeping the lower rated battery installed.

On a side note - Battery Size Change (As-Builts)
BCM - 726-04-01
(XL/XLT) - 0101-0000-093D
(Lariat) - 0201-0000-093E

x1xx-xxxx-xxxx - (1) equals H6 - 70 Amp Hour
x2xx-xxxx-xxxx -(2) equals H7 - 80 Amp Hour

The easy menus make it confusing (in the wording) along the line as far as the size, this is the actual line that is changed from that easy menu, and it changes the 1 to a 2.

In other words, don't make the change until you actually change the battery right?

 

[Superspirit]

If you want to make a change without changing the battery, then change the state of charge to 90%

 

[Ohwell]

If you want to make a change without changing the battery, then change the state of charge to 90%

I thought about that, but I don't want to make a change that could affect my extended warranty. I went 2 years with my battery's state of health reading 100%; then last fall it had dropped to 80%, both the dealership's reading and my meter reading. I added the Battery Minder desulfator and topped the battery off twice a week with my Noco all winter, and my battery now reads 95% state of health, so it might be quite a while before I replace the battery. I also started driving in sport mode for all in-town driving, and the few extra rpm's seem to charge the battery better.

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