Battery Maintainer - Where did you put the plug?

[MakinDoForNow]

Thought it would be good to point out to others reading this, because this idea of reseting the BMS to get out of this issue is mentioned every once in awhile as a solution.
As you've proven it may for a time seem to work.
But it's not a good idea.

Because reseting the BMS only tells the system - here's a new battery with full charge - learn from here.
As one item, it tracks battery age.
Another set of items, it tracks charges and discharges accumulated while key on and key off.

So if you got a low battery because it thought a drop of 0.4 V was constant change, then it turns on battery saver features.
Then you BMS reset it, and now say 12.2 is the new level to start from.
Now it drops to 11.8 say, and the saver kicks on again.

Of course this is merely chasing an issue into a worse condition, as the initial fast charging it does when you start driving - just doesn't happen as long as it needs to if it thinks the battery is already at upper level of charge, from the last BMS reset.

As the manual mentions - that reset is for when you change the battery, and as recommended even that should be topped off with trickle charge.

I'd recommend some night after a multi-day charge, disconnect the charger, do your last BMS reset, lock truck, and let it learn overnight. Per the manual instructions.
Let it see what full charge is again and reset it's "expectations".

Love this. I am in 34th month of my 2022 hybrid and. Every three or 4 months I put my noco genius 5 on its 12v and try to leave it for 7 days with truck locked. Can take one or two days before entering maintenance mode. Then I can catch it running top off and optimization about every day. Not sure if the 8 hour learn procedure repeats every 24 hours so I will unlock and relock truck on several times if I think of it. Idea being for the learn procedure to see battery with the random draw replaced several days in a row. I have never had a deep sleep but have had no dome light several times. It has been posted that the battery learn procedure does not update the battery install date ( does this mean dealer has to do it? Seems like someone posted he updated with for scan but it reset to original date the next day???) so, I assume my BMS has adjusted its charge routine for an aged battery. (Most likely the date the dealer sets as "in service/warranty" date). The bxt99rt OEM is a three year battery. Of interest is my dealer is sending DAILY EMAILS for me to bring my battery in to be checked starting about 60 days prior to my 36 month of in-service. I'm going in next week.

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[Bruce W]

Love this. I am in 34th month of my 2022 hybrid and. Every three or 4 months I put my noco genius 5 on its 12v and try to leave it for 7 days with truck locked. Can take one or two days before entering maintenance mode. Then I can catch it running top off and optimization about every day. Not sure if the 8 hour learn procedure repeats every 24 hours so I will unlock and relock truck on several times if I think of it. Idea being for the learn procedure to see battery with the random draw replaced several days in a row. I have never had a deep sleep but have had no dome light several times. It has been posted that the battery learn procedure does not update the battery install date ( does this mean dealer has to do it? Seems like someone posted he updated with for scan but it reset to original date the next day???) so, I assume my BMS has adjusted its charge routine for an aged battery. (Most likely the date the dealer sets as "in service/warranty" date). The bxt99rt OEM is a three year battery. Of interest is my dealer is sending DAILY EMAILS for me to bring my battery in to be checked starting about 60 days prior to my 36 month of in-service. I'm going in next week.

This is fascinating information. I followed the online advice and reset my BMS but am probably doing it improperly, at lower voltage levels. No wonder the truck never charges the battery fully. It is confused about

Thought it would be good to point out to others reading this, because this idea of reseting the BMS to get out of this issue is mentioned every once in awhile as a solution.
As you've proven it may for a time seem to work.
But it's not a good idea.

Because reseting the BMS only tells the system - here's a new battery with full charge - learn from here.
As one item, it tracks battery age.
Another set of items, it tracks charges and discharges accumulated while key on and key off.

So if you got a low battery because it thought a drop of 0.4 V was constant change, then it turns on battery saver features.
Then you BMS reset it, and now say 12.2 is the new level to start from.
Now it drops to 11.8 say, and the saver kicks on again.

Of course this is merely chasing an issue into a worse condition, as the initial fast charging it does when you start driving - just doesn't happen as long as it needs to if it thinks the battery is already at upper level of charge, from the last BMS reset.

As the manual mentions - that reset is for when you change the battery, and as recommended even that should be topped off with trickle charge.

I'd recommend some night after a multi-day charge, disconnect the charger, do your last BMS reset, lock truck, and let it learn overnight. Per the manual instructions.
Let it see what full charge is again and reset it's "expectations".

this makes sense. I think I have been making issues worse by resetting my BMS wrong. No wonder the vehicle won’t maintain proper voltage levels. Will try your advice.

 

[jb_cb900]

Laid the connector for the charger on top of the air intake grate and secured with a zip tie. No need to open the hood. Just make sure to put it back on the grate when finished so it won't wind up in the wiper well. One wrap of the cord around the mirror provides strain relief and visibility so I don't drive off and rip the charger out of the wall.
Thanks goodness I have a loud blinker. How embarrassing would it be driving down the road dragging a battery charger AND leaving your blinker on for miles?

 

[MakinDoForNow]

This is fascinating information. I followed the online advice and reset my BMS but am probably doing it improperly, at lower voltage levels. No wonder the truck never charges the battery fully. It is confused about

this makes sense. I think I have been making issues worse by resetting my BMS wrong. No wonder the vehicle won’t maintain proper voltage levels. Will try your advice.

Some insight on "How good is this battery?" by reading and thinking and rereading the manufacturer warranty. For instance a top of line AGM with a ten year design life with a steel case and 99.9+% pure lead. Steel case allows a higher internal pressure to keep any generated gasses in solution to allow higher internal temps and gas can be condensed when battery cools. The ten year warranty can be reduced to 2-4 years if placed in vehicles with computers, start/stop, Other stuff. If it's drawn down to 10volts. It's required to be removed and placed on recover charge procedure. Yes warranties have lots of CYA language but I see this as evidence that just slapping in a cheapo AGM may not be as good a solution as expected. Yes most likely at least as good As OEM. The coming reprogram or whatever in q1-25 will most likely be great answer.

 

[Bruce W]

Some insight on "How good is this battery?" by reading and thinking and rereading the manufacturer warranty. For instance a top of line AGM with a ten year design life with a steel case and 99.9+% pure lead. Steel case allows a higher internal pressure to keep any generated gasses in solution to allow higher internal temps and gas can be condensed when battery cools. The ten year warranty can be reduced to 2-4 years if placed in vehicles with computers, start/stop, Other stuff. If it's drawn down to 10volts. It's required to be removed and placed on recover charge procedure. Yes warranties have lots of CYA language but I see this as evidence that just slapping in a cheapo AGM may not be as good a solution as expected. Yes most likely at least as good As OEM. The coming reprogram or whatever in q1-25 will most likely be great answer.

we can only hope

 

[Dad]

Thought it would be good to point out to others reading this, because this idea of reseting the BMS to get out of this issue is mentioned every once in awhile as a solution.
As you've proven it may for a time seem to work.
But it's not a good idea.

Because reseting the BMS only tells the system - here's a new battery with full charge - learn from here.
As one item, it tracks battery age.
Another set of items, it tracks charges and discharges accumulated while key on and key off.

So if you got a low battery because it thought a drop of 0.4 V was constant change, then it turns on battery saver features.
Then you BMS reset it, and now say 12.2 is the new level to start from.
Now it drops to 11.8 say, and the saver kicks on again.

Of course this is merely chasing an issue into a worse condition, as the initial fast charging it does when you start driving - just doesn't happen as long as it needs to if it thinks the battery is already at upper level of charge, from the last BMS reset.

As the manual mentions - that reset is for when you change the battery, and as recommended even that should be topped off with trickle charge.

I'd recommend some night after a multi-day charge, disconnect the charger, do your last BMS reset, lock truck, and let it learn overnight. Per the manual instructions.
Let it see what full charge is again and reset it's "expectations".

This makes good sense and is great advice.

 

[Dad]

I am starting to wonder what I have gotten myself into. My Maverick Lariat Hybrid should be delivered in March. I live in Mississippi and before that in Texas, and I have never had to use a battery maintainer or charger on a regular basis in 58 years of driving. The only time I used a charger was to get to where I could get a new battery and install it, or when I had skipped maintenance and let my battery terminals become corroded. My 2021 RAV4 had a dead battery twice in the first 2 weeks I had it. Toyota installed new software that should have been installed before it left the factory and I have never had an issue since. It normally gets driven around 10 miles a day. Has Ford really become this incompetent? Are new vehicles really this complicated? If my battery is dead how do I get in my truck?

There's a physical key hidden at the top of the key fob. Behold:

 

[HeyBales]

Love this. I am in 34th month of my 2022 hybrid and. Every three or 4 months I put my noco genius 5 on its 12v and try to leave it for 7 days with truck locked. Can take one or two days before entering maintenance mode. Then I can catch it running top off and optimization about every day. Not sure if the 8 hour learn procedure repeats every 24 hours so I will unlock and relock truck on several times if I think of it. Idea being for the learn procedure to see battery with the random draw replaced several days in a row. I have never had a deep sleep but have had no dome light several times. It has been posted that the battery learn procedure does not update the battery install date ( does this mean dealer has to do it? Seems like someone posted he updated with for scan but it reset to original date the next day???) so, I assume my BMS has adjusted its charge routine for an aged battery. (Most likely the date the dealer sets as "in service/warranty" date). The bxt99rt OEM is a three year battery. Of interest is my dealer is sending DAILY EMAILS for me to bring my battery in to be checked starting about 60 days prior to my 36 month of in-service. I'm going in next week.

The dealer likely has their scan tool able to change the PID value for battery age in days (not a date), if they really know that, I'm betting they wouldn't bother to do the math to enter it.
On mine, the BMS reset did reset that days field, both times I've done it. 2nd time is when I realized this isn't good as battery age is used in some SOC% calculations.

It seems the relearn process just occurs, or is considered done, when enough time did pass to learn what the voltage drop was with the BMS watching all micro-draws thru the night, and having a value after the chunk of time to record.

On 3 tests of this routine, after a full charge up, the system reported SOC% was barely better than before the full charge. Maybe 5%. But the charger reported starting around 50% to of course 100%. Even removed the trickle charge, turned on lights briefly, let battery sit for a bit to lose the surface charge, and still 100% reported by charger.
And this was charged under the hood, so no bypassing the BMS.
Next morning system SOC% was 77-80%. (only the 1st time did I do a BMS reset, other 2 times merely a relearn).
The drive after only allowed getting up to 80% max.
Then after a few days it noise-dives to max 65% during a drive, usually hanging out around 50-60%.

I've stopped charging it - I figure the battery is too far gone with truck charging routine, besides sitting on shelf for 6 months, and I want a new one sooner than later to then properly do the maintainer routine you've described. So I need it to die.
Cold 30-35 F mornings it's sitting at 11.8 V - so it won't be long hopefully.

 

[HeyBales]

This is fascinating information. I followed the online advice and reset my BMS but am probably doing it improperly, at lower voltage levels. No wonder the truck never charges the battery fully. It is confused about

this makes sense. I think I have been making issues worse by resetting my BMS wrong. No wonder the vehicle won’t maintain proper voltage levels. Will try your advice.

Oh - please don't get the wrong idea.
With the current charging logic it is still stupidly not going to fully charge when it could.
And doing that on a not great quality battery isn't going to help the battery last.
But it should help until a mentioned software update comes out 1Q.

 

[MakinDoForNow]

The dealer likely has their scan tool able to change the PID value for battery age in days (not a date), if they really know that, I'm betting they wouldn't bother to do the math to enter it.
On mine, the BMS reset did reset that days field, both times I've done it. 2nd time is when I realized this isn't good as battery age is used in some SOC% calculations.

It seems the relearn process just occurs, or is considered done, when enough time did pass to learn what the voltage drop was with the BMS watching all micro-draws thru the night, and having a value after the chunk of time to record.

On 3 tests of this routine, after a full charge up, the system reported SOC% was barely better than before the full charge. Maybe 5%. But the charger reported starting around 50% to of course 100%. Even removed the trickle charge, turned on lights briefly, let battery sit for a bit to lose the surface charge, and still 100% reported by charger.
And this was charged under the hood, so no bypassing the BMS.
Next morning system SOC% was 77-80%. (only the 1st time did I do a BMS reset, other 2 times merely a relearn).
The drive after only allowed getting up to 80% max.
Then after a few days it noise-dives to max 65% during a drive, usually hanging out around 50-60%.

I've stopped charging it - I figure the battery is too far gone with truck charging routine, besides sitting on shelf for 6 months, and I want a new one sooner than later to then properly do the maintainer routine you've described. So I need it to die.
Cold 30-35 F mornings it's sitting at 11.8 V - so it won't be long hopefully.

29°F this am dash monitor showed 11.8V however that's after opening door and pushing button without brake for accessory mode so 11.8 is open circuit reading with ford only knows what else is drawing amps checking or doing what. Has to be something three days earlier at 65°F was 12.2v. I'm thinking I need to put voltage monitor on battery with remote separate battery power I can turn on and read battery prior to even opening door. Today the power point monitor showed 15.5 at startup and 15.3 an hour later so lots of amps heating plus ??? One would think after an hour it would be below 15 at least. I would not be surprised if the bms is not pulse charging battery and waiting some time to let battery to internally cool part of time. I have pondered putting a voltage stabilizer limiting to 14.6-14.8 on the pos post. But of course won't!

 

[HeyBales]

29°F this am dash monitor showed 11.8V however that's after opening door and pushing button without brake for accessory mode so 11.8 is open circuit reading with ford only knows what else is drawing amps checking or doing what. Has to be something three days earlier at 65°F was 12.2v. I'm thinking I need to put voltage monitor on battery with remote separate battery power I can turn on and read battery prior to even opening door. Today the power point monitor showed 15.5 at startup and 15.3 an hour later so lots of amps heating plus ??? One would think after an hour it would be below 15 at least. I would not be surprised if the bms is not pulse charging battery and waiting some time to let battery to internally cool part of time. I have pondered putting a voltage stabilizer limiting to 14.6-14.8 on the pos post. But of course won't!

So this morning only 40 F.
Put on acc key mode so OBD port powered and power port with reader.

11.7 in both Forscan PID and reader.
After started, then 15.2 shown for both quickly, then port reader started going lower, so other things likely brought on line.

But good to know the port is a viable place to get decent readings over time, especially somewhat resting. My lights/screen turn off really quick now. Hmmm, wonder why...

(Now, my reader appears to be 0.25 higher than multi-meter checked in the port, so sometimes appears 0.2 or 0.3 higher. So my initial morning read is still "oh that's not good", then realization "oh that's really bad".)

 

[MakinDoForNow]

So this morning only 40 F.
Put on acc key mode so OBD port powered and power port with reader.

11.7 in both Forscan PID and reader.
After started, then 15.2 shown for both quickly, then port reader started going lower, so other things likely brought on line.

But good to know the port is a viable place to get decent readings over time, especially somewhat resting. My lights/screen turn off really quick now. Hmmm, wonder why...

(Now, my reader appears to be 0.25 higher than multi-meter checked in the port, so sometimes appears 0.2 or 0.3 higher. So my initial morning read is still "oh that's not good", then realization "oh that's really bad".)

The lights will start turning off when The 12v buss approaches 11.9 where they won't come on. I guessing with something else or even them on the buss drops to 11.8 or whatever causing them to turn off. Then without draw the bus comes up a little. The voltage at the end will vary depending on what if anything is using voltage between the and and the power port. For the closest true value the voltage needs to be taken at the actual positive battery post. Remember that these are open circuit readings. That's why good plumbers tap the water lines for the shower before the sink and commode to minimize temperature changes in shower spray when flushing, etc. re: power port stays active when truck is turned off and you can watch battery drop as it settles. (My reader is in 0.1v precision. Would be nice to have 0.01v precision). Sit there for a few minutes and watch battery settle. If you leave truck and come back 45 minutes later opening the door will drop the reading 0.1-0.2, even if everything possible is turned off. Need a reader on pos post! Preferably with separate powered blue tooth to your phone/reader.
ETA: if you get into truck and push the power port reader in to turn it on when you put truck into accessory mode you can see the battery reading (reduced by open circuit losses) for about 1/2-1 second before the dcdc inverter comes online. You have to be looking at it when you ready truck. Turn headlight draw and cabin and all accessories off before ready truck action.

 

[DWV]

Back to the original question of where do you put the maintainer port.
Here’s where I put mine and wired it to the under hood, jumping point for positive and directly to one of the grounds on the frame.

 

[Dad]

Look at yours closely. My noco has clamps but the clamps are attached with eyelets bolted on to clamps. Maybe yours does also.

Thank you. I will check that out. The other issue is the larger size of my clamp on maintainer. I’m partial to the NOCO due to its much smaller size. Also not sure how mine would hold up in a heated engine bay.

 

[Ozarkbeard]

If my battery is dead how do I get in my truck?

Uh, use the key.

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