Battery, BMS , charging questions?

[HeatXfer]

The amount of useful information in these threads and the commitment to follow through and resolution is remarkable. Everytime I explore an issue or try to suss out an answer, I turn to this forum and find a masterclass on suspension, tires, electrical and everything Ranger. I didn't want to start yet another BMS/Charging system thread, so this thread it is:

I replaced the original battery after 3½yrs after getting the "start the engine or else" message. I installed a new AGM ($$$), I did not reset the BMS ('cause I hadn't read it here yet), and a year later all the alert tones changed and I start getting "the message" again.

I check the forum, disco the BMS and break out the 'ol Batery Tender. I've got a volt meter plugged into thr cigarette lighter and everything looked good: off the tender and not driven for several days I had 12.4 - 12.6v, up to 14.4v while driving. I reset the BMS to 90% and have been monitoring: no issues, I haven't had to use the tender. All good.

Then I decided to reset the BMS. I'm now seeing charging voltage as high as 15.4v, but typically at 15.15v. It's been doing this for about a week, with and without the BMS. I have yet to see it drop into normal range. Could this be the 'refresh' cycle because the battery was run down before?

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[TJC]

Those 15+ Volts typically are the surge voltages when decelerating or coasting to a stop. This is the BMS in action. I'd disconnect the BMS sensor cable and watch the voltages on a short drive. They should be well below 15v and after about 10 miles should begin to drop.

This would verify that the BMS is behaving as Ford designed it. Sounds like all your setting have been reset to Ford's defaults.

FWIW, If you are measuring voltages from inside the cab, they are actually .2v-.3v lower than what is going into the battery. Your 15.4v measured voltage is actually 15.7v at the battery terminals.

Best of luck!

- T

 

[TJC]

I also have to ask, what is your new battery's charge state?

 

[JesseS]

So if I up the battery threshold it will charge it more and this should help my stop start work properly?

I used forscan to up the SOC to 90% 3 years ago and am still on the original battery with no issues.

 

[Rviator]

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Are there any side effects from unplugging BMS sensor from the battery?

https://www.ranger5g.com/forum/thre...nd-how-to-properly-charge-your-battery.22516/

 

[Scottlane1171]

I used forscan to up the SOC to 90% 3 years ago and am still on the original battery with no issues.

Does you start/stop function ok?

 

[got3fords]

I used forscan to up the SOC to 90% 3 years ago and am still on the original battery with no issues.

I am also on the original at just under 3 years. All I did was add an on-board desulfator. I changed nothing else. ASS still works if I leave it on. I keep on eye on the voltage with a 12V outlet meter. (I know it's slightly lower than right at the battery.) Seems like the regen charging doesn't work much in colder weather.

 

[JesseS]

I am also on the original at just under 3 years. All I did was add an on-board desulfator. I changed nothing else. ASS still works if I leave it on. I keep on eye on the voltage with a 12V outlet meter. (I know it's slightly lower than right at the battery.) Seems like the regen charging doesn't work much in colder weather.

I have never had a battery sulfate to the point of failure, and AGM's are less prone to sulfating than flooded. Rather than add a plug in accessory I felt up'ing the SOC was the best for me, I didn't like the lack of battery reserve power.

 

[JesseS]

Does you start/stop function ok?

Yes, works fine, although I don't use it much so added the auto on/off module.

 

[HeatXfer]

Those 15+ Volts typically are the surge voltages when decelerating or coasting to a stop. This is the BMS in action. I'd disconnect the BMS sensor cable and watch the voltages on a short drive. They should be well below 15v and after about 10 miles should begin to drop.

This would verify that the BMS is behaving as Ford designed it. Sounds like all your setting have been reset to Ford's defaults.

FWIW, If you are measuring voltages from inside the cab, they are actually .2v-.3v lower than what is going into the battery. Your 15.4v measured voltage is actually 15.7v at the battery terminals.

Best of luck!

- T

Oddly enough, on a 80mile round trip this morning, my driving & idling voltages were about 14.2 and 13.6 respectively; never climbed over 14.5v. When I start after sitting for a while the voltage goes right to 14.2 and then drops to around 13.2. I did reset the BMS to 70% prior my trip this morning, but I will reset it to 90%

I also have to ask, what is your new battery's charge state?

At this point it's a year old, but I'll check it after it's been sitting for a while. Before starting this morning it was 12.3v on the little plug-in volt meter.

Thanks all!

 

[TJC]

The little plug in voltmeter is plugged into a port in the cab? If so add .2-.3v to the number. You are actually at 12.5v-12.6v

12.65v - 12.7v (after sitting for 4-8 hours, the battery must be in a rested state to get an accurate reading) is your optimal range.

 

[got3fords]

I have never had a battery sulfate to the point of failure, and AGM's are less prone to sulfating than flooded. Rather than add a plug in accessory I felt up'ing the SOC was the best for me, I didn't like the lack of battery reserve power.

Sulfation is the most common cause of lead acid battery failure (including AGM). If you ever had a battery fail, what was the cause?

 

[Frenchy]

Sulfation is the most common cause of lead acid battery failure (including AGM). If you ever had a battery fail, what was the cause?

As much as you are correct on that most of the time battery failures come down to individuals not charging batteries correctly and misusing batteries. I run into this quite often in the forklift world since there are many different types of electric forklifts. Another failure at least for automotive type batteries that's very common it's just the fact that most batteries are made very cheaply by Johnson Controls causing the batteries to have very s***** designs causing premature failure

 

[JesseS]

Sulfation is the most common cause of lead acid battery failure (including AGM). If you ever had a battery fail, what was the cause?

Re-read please, I said AGM's ARE LESS PRONE to sulfating than flooded, not that they didn't. I had a battery fail to bubbles in the battery post that arched and almost caused a fire due to heavy load from an inverter. Factory defect & was replaced free. Another exploded and blew the top off.

 

[HeatXfer]

The little plug in voltmeter is plugged into a port in the cab? If so add .2-.3v to the number. You are actually at 12.5v-12.6v

12.65v - 12.7v (after sitting for 4-8 hours, the battery must be in a rested state to get an accurate reading) is your optimal range.

The truck's been sitting for 6hrs, voltage at 12.58v. I'll check it again in the morning. The BMS is connected, so there is a steady .8amp draw.

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