Battery SOC

[Ducati1098]

Who could see via remote your SOC was low?? The dealer can see that??

Yes, it’s in connected data

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[Brian_B]

Curious. I wonder if they did this intentionally or was it accidental consequence of other trouble shooting/testing efforts? I suspect the latter.

Just off the top of my head, I can't think of a reason why a reset forcing the BMS to treat a battery at the end of it's life (and thus not holding volts/amps like a new one) would be helpful in extending the functionality of an end-of-life battery (on the contrary). In other words, the BMS is supposed to treat an end of life battery in such a way to help it "keep up" with the Bronco's demands...

To my knowledge, and I don't know this for certain to be true, just what I've gathered from my own observations and posts around here:

The BMS reset won't fix a bad battery, but there is a chance the BMS itself could have corrupt data.

Most of the time these batteries go, it's that they fail to hold a charge. You can top them off manually with a charger, and they are discharged back to Deep Sleep within a few days. They take hundreds of miles to recharge via driving. The BMS will sit at very high charge rates for a long time (14.5V-15.x steady). Those are all symptoms of a dying battery.

But there is a chance it's just the BMS has a faulty SOC read, or can't get a SOC refresh. It takes something like an 8 hour idle period for the BMS to do a SOC refresh (not the same thing as the reset sequence) and get a new baseline SOC. If the BMS can't do that because of corrupt data, or heavy vehicle use, or something -- then a BMS reset ~might~ get you back up and running.

If nothing else, it's a last ditch effort to try before throwing another $300 AGM battery at the problem that doesn't cost anything. And occasionally it seems to work, according to reports. But if the BMS isn't the problem, you will see the battery going right back to what it's been doing - the BMS reset won't actually fix anything.

There have also been a few reports of a dying alternator. It's not nearly as common as a bad battery, but something to keep in mind.

The majority of the time, it's the battery, but there are those corner cases to watch out for before you just throw parts at it.

 

[Brian_B]

And for folks that think the battery only needs to start the vehicle and the alternator takes over everything from there on out....

Close. The steady state loads the alternator can definitely carry... but there are large spikes in load, such as heavy use of electric steering, winch pulls, electric brake boosters, etc... the alternator can't take the instantaneous sudden hit of those big loads. The alternator can pick up after a second or two and carry it, but it's not beefy enough to hold the voltage constant when those big things initially hit.

The battery is what it supposed to be that shock absorber on your electrical system, then the alternator comes in and keeps the battery topped off. If the battery is weak, those big hits can cause voltage to drop by a lot. The onboard electronics ~hate~ that, and it can cause all kinds of random issues - up to and including Check Engine lights, failure of 4WD, engine stalling, braking issues, etc.

An awful lot on these Broncos is electric driven, and governed by computers.

Usually the first symptom of a dying battery isn't "Deep Sleep" or the motor not cranking when you start, but random weird electrical issues start popping up out of the blue.

 

[B22-2023]

If nothing else, it's a last ditch effort to try before throwing another $300 AGM battery at the problem that doesn't cost anything.

Agreed and recommend - - battery at zero, can’t take a charge: top up via jumpers from running vehicle to get its threshold voltage up.
disconnect battery from everything. Esp. BMS device.
- charge whatever good managed charging system you have for AGM. I use Battery Tender 4 Amp - for 1-2 days in my one case
- reconnect
- test the battery if you have a tester
- Forscan or do the in-cabin steps to reset the BMS.
- if the battery is good or comes back, you’ll know.

In my case, I did it all and battery would only get to 60 pct SOC. Dealer said sure, but we will test the battery in-house and IF it’s just worn out enough in line with a 2.75 year old battery, no warranty replacement. In my case, admittedly due to a few years of deep cycling it camping, the battery was seen by Ford to be bad.

A month later, I lost the new battery charge to zero-ish SOC via a slow short. All the steps above, brought it back to full SOC, rather than calling it “faulty”.

 

[jtgensler]

Was there a consensus on best way to monitor SOC w/o access to FRDS?
OBD2 - Forscan app on phone?
Or would one of the simple code readers from HF or similar be able to give me the SOC number?

I've been having issues & just installed a NOCO 10 Genius to keep mine topped up regularly but I'm not sure how often I need to do it.
Was planning on just hooking it up overnight 1x / week, but I want to be able monitor to see if that's effective or if I need to do it more frequently.

 

[Brian_B]

Was there a consensus on best way to monitor SOC w/o access to FRDS?
OBD2 - Forscan app on phone?
Or would one of the simple code readers from HF or similar be able to give me the SOC number?

I've been having issues & just installed a NOCO 10 Genius to keep mine topped up regularly but I'm not sure how often I need to do it.
Was planning on just hooking it up overnight 1x / week, but I want to be able monitor to see if that's effective or if I need to do it more frequently.

Most any ODB scanner app should do it - Forscan Lite is just one, I used OBDLink that came with the MX+. I believe you find the SOC in the BdyCM (Body Control Module). On OBDLink, it's listed as "Vehicle Battery State of Charge - Estimated". I think in Forscan it's called BATT_SOC

 

[crenca]

I've been having issues & just installed a NOCO 10 Genius to keep mine topped up regularly

That device is "smart" charger, in other words it has a BMS built in. This means it's likely to only charge your battery to 80% (or some number close to that) SOC the same as the broncos BMS would.

In other words without knowing more about your problems and goals, it is possibly superfluous...

 

[jtgensler]

That device is "smart" charger, in other words it has a BMS built in. This means it's likely to only charge your battery to 80% (or some number close to that) SOC the same as the broncos BMS would.

In other words without knowing more about your problems and goals, it is possibly superfluous...

That's fine. I'm not trying to go past the OEM setting.
My issue is that my charge is getting down to like 48% in only a few weeks because I only commute like 1 mile a day during the week.
So I'm not running it enough to offset the starts.
I was getting awd & 4wd system issues tied to SOC levels being low.
So I'm just trying to supplement the charges to keep it topped off near that 80% or factory setting
Basically I just want to have a way of checking SOC to know when I need to put it on the charger for a night.

 

[crenca]

That's fine. I'm not trying to go past the OEM setting.
My issue is that my charge is getting down to like 48% in only a few weeks because I only commute like 1 mile a day during the week.
So I'm not running it enough to offset the starts.
I was getting awd & 4wd system issues tied to SOC levels being low.
So I'm just trying to supplement the charges to keep it topped off near that 80% or factory setting
Basically I just want to have a way of checking SOC to know when I need to put it on the charger for a night.

That makes sense. Although I've never used it (only the full version ) I would think forscan lite with Bluetooth MX link that Brian recommended would be a good solution for your use case.

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