Confusion: 12v Battery Connections Under the Hybrid Hood

[MakinDoForNow]

Yes, I've seen that and understand the concern. It is becoming a concern for me as well, just something I never thought would be a problem.

I am wondering if this is a real world issue or just something that happens when something else is wrong. For example many (most?) of the complaints I have seen about the deep sleep issue seem to eventually lead to being caused by a failure of the HV battery harness and thus the 12v battery not getting charged.

So my question is: if there is no problem with the HV battery harness is there then no problem with the 12v battery system going into deep sleep in a reasonable time? For me 'reasonable' would be letting the truck sit untouched a minimum of 4 weeks. I think a vehicle that goes dead after sitting only a month is a complete travesty.

Yes we can add battery maintainers, but why should we have to?

The harness with the "bad" end is 12v (it is black and not orange) and is from the 12v to the dcdc converter with drops in between for different things. The deep sleep occurs when 12v drops to a low voltage that cannot trip contacts for the hvb and ready the vehicle. There are many things that could cause phantom drains on 12v. I have voltage monitor in my XLT LUX dash PowerPoint and I turn key to accessory and read bus voltage (it is an open circuit reading so is affected by whatever is drawing current). I have never had lights not come on or deep sleep. I have seen overnight drops of 0.1-0.2v between readings 2 hours after parking and next morning. I have seen voltage as low as 11.6 but normally higher. If it's less than 12.1v I will place truck in ready state and charge battery. I think I drive mine often enough that I shouldn't have deep sleep or even light problems, but my concern is long term battery health which could be offset by monthly or quarterly use of my noco maintainer.

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[Dad]

Yes, I've seen that and understand the concern. It is becoming a concern for me as well, just something I never thought would be a problem.

I am wondering if this is a real world issue or just something that happens when something else is wrong. For example many (most?) of the complaints I have seen about the deep sleep issue seem to eventually lead to being caused by a failure of the HV battery harness and thus the 12v battery not getting charged.

So my question is: if there is no problem with the HV battery harness is there then no problem with the 12v battery system going into deep sleep in a reasonable time? For me 'reasonable' would be letting the truck sit untouched a minimum of 4 weeks. I think a vehicle that goes dead after sitting only a month is a complete travesty.

Yes we can add battery maintainers, but why should we have to?

100% agree!

 

[Ken L]

I will probably be installing a battery maintainer on my (yet to be built, tentatively last week of April 23) XLT Hybrid. My thoughts are for installation under the hood using the red + boost connection and the negative post near the fender. Being retired, my vehicle my not be used for 5-7 days at a time and in the winter here may not be good. If the Maverick was started and driven everyday, that would probably be a different story.
A bit of my experience. I had a c-class motor home built on an 06 Ford E450 cab and chassis. With the parasitic draws in the Ford system, the battery would be dead after a week to 10 days of sitting. I installed a battery maintainer attached to the battery cable that ran from the Ford battery to connect to the Winnebago electrical system. It was about 8 ft from the battery to the maintainer, and worked as it should for 15 years (sold MH). The original equipment Ford battery finally died in 2020 after 14yrs.

Ken

 

[colinl]

I will probably be installing a battery maintainer on my (yet to be built, tentatively last week of April 23) XLT Hybrid. My thoughts are for installation under the hood using the red + boost connection and the negative post near the fender. Being retired, my vehicle my not be used for 5-7 days at a time and in the winter here may not be good. If the Maverick was started and driven everyday, that would probably be a different story.
A bit of my experience. I had a c-class motor home built on an 06 Ford E450 cab and chassis. With the parasitic draws in the Ford system, the battery would be dead after a week to 10 days of sitting. I installed a battery maintainer attached to the battery cable that ran from the Ford battery to connect to the Winnebago electrical system. It was about 8 ft from the battery to the maintainer, and worked as it should for 15 years (sold MH). The original equipment Ford battery finally died in 2020 after 14yrs.

Ken

Yes, you'll want to use those jump point connections. Make sure you get a battery tender compatible with AGM batteries, don't go cheap!

 

[MakinDoForNow]

Yes, you'll want to use those jump point connections. Make sure you get a battery tender compatible with AGM batteries, don't go cheap!

I don't know Ecoboost battery type but Hybrid has sealed, vented, flooded "enhanced" (to apparently charge more like a deep cycle) battery and is not an agm battery. (Always confirm your battery type before charging!).

 

[colinl]

I don't know Ecoboost battery type but Hybrid has sealed, vented, flooded "enhanced" (to apparently charge more like a deep cycle) battery and is not an agm battery. (Always confirm your battery type before charging!).

Even if that is the case you'll likely replace it with AGM and any charger than can accept AGM will also work with flood. The reverse isn't necessarily true.

 

[Ken L]

Thanks, I will check out the specs on the Noco? and Battery Tender brands, and others. The old one sold with MH was a Canadian Tire store brand label.

Ken

 

[Dad]

I will probably be installing a battery maintainer on my (yet to be built, tentatively last week of April 23) XLT Hybrid. My thoughts are for installation under the hood using the red + boost connection and the negative post near the fender. Being retired, my vehicle my not be used for 5-7 days at a time and in the winter here may not be good. If the Maverick was started and driven everyday, that would probably be a different story.
A bit of my experience. I had a c-class motor home built on an 06 Ford E450 cab and chassis. With the parasitic draws in the Ford system, the battery would be dead after a week to 10 days of sitting. I installed a battery maintainer attached to the battery cable that ran from the Ford battery to connect to the Winnebago electrical system. It was about 8 ft from the battery to the maintainer, and worked as it should for 15 years (sold MH). The original equipment Ford battery finally died in 2020 after 14yrs.

Ken

I'm in a similar situation with my Maverick and considered the battery maintainer to the point of purchasing one. I haven't used it yet since lately the Maverick has been a workhorse of moving from one house to another. Not that it matters apparently. Drove 30 miles to and from my daughter's choir practice and still got the deep sleep blues.
I have a 07 C -class same Ford E450 in storage and while I have a solar battery maintainer for it, one has to have a fully charged battery for it to be effective. Still haven't found the time to jump it and drive it around for an hour or so to charge it up. Just another project in the wings.

 

[AutobahnSHO]

So a little funny about "connect to the frame"- that doesn't work if the frame is painted?....

A bare metal surface is best of course.

A few years back I was working with Army satellite trailers- equipped also with a generator to get internet anywhere in the world without power.. Some of the Soldiers were chastised for not connecting the trailers to the grounding rods (which were embedded in concrete). I came out a different day and they had indeed connected the grounding wires- clamped to large ver-thiick-painted metal shipping containers which were sitting on the concrete. (shaking my head)

 

[mhw21zap]

Original question about where to mount an onboard battery tender I'm also interested in an answer to that. Do you connect directly to the battery under the rear seat and run your extension cord out the rear window to an electrical outlet or do you find a space in the engine compartment and connect to the red (+) post as listed above and to the neg (-) body bolt as indicated for jumper cables?

I am trying to accurately answer this question as well. I've not yet seen a conclusive answer, have you sorted it out by chance? 2 dead batteries in the 1st month of ownership :/ I'm trying anything I can

 

[colinl]

I am trying to accurately answer this question as well. I've not yet seen a conclusive answer, have you sorted it out by chance? 2 dead batteries in the 1st month of ownership :/ I'm trying anything I can

2 dead batteries, how? If you use a cheap charger it's going to overcharge and ruin any battery. If it doesn't have a voltage cutoff you don't want it.. a timer is not sufficient.

 

[mhw21zap]

2 dead batteries, how? If you use a cheap charger it's going to overcharge and ruin any battery. If it doesn't have a voltage cutoff you don't want it.. a timer is not sufficient.

Yes, after a month of ownership I've woken up to 2 dead batteries on my way to work. I drive my truck 30-40 miles each day, and both times there were no lights, A/C, or radio features left on. I used my Noco both times and thankfully got it started.

Took it to the dealership this week, they replaced my 12V battery which they uncovered a bad cell upon as well as did the updates/error message reset. I was feeling good driving home last night.

Woke up this morning to another Deep Sleep, drove it work (didn't need a jump this time as the notification was received only about an hour before I woke up and left.

Got to work an hour later and sure enough, an hour after that, my 2nd deep sleep notification.

2 deep sleeps less than 12 hours after replacing a faulty battery.

 

[colinl]

Yes, after a month of ownership I've woken up to 2 dead batteries on my way to work. I drive my truck 30-40 miles each day, and both times there were no lights, A/C, or radio features left on. I used my Noco both times and thankfully got it started.

Took it to the dealership this week, they replaced my 12V battery which they uncovered a bad cell upon as well as did the updates/error message reset. I was feeling good driving home last night.

Woke up this morning to another Deep Sleep, drove it work (didn't need a jump this time as the notification was received only about an hour before I woke up and left.

Got to work an hour later and sure enough, an hour after that, my 2nd deep sleep notification.

2 deep sleeps less than 12 hours after replacing a faulty battery.

Reset the battery monitor.

 

[mhw21zap]

Reset the battery monitor.

I will give that a shot after work. What might that help though given that I've got some form of parasitic drain? I just did a voltage meter reading and showed 12.53V off / 14.62V on. Could it be that the 2 most recent deep sleep notifications were caused / triggered by the Battery Monitor not functioning properly?

 

[colinl]

I will give that a shot after work. What might that help though given that I've got some form of parasitic drain? I just did a voltage meter reading and showed 12.53V off / 14.62V on. Could it be that the 2 most recent deep sleep notifications were caused / triggered by the Battery Monitor not functioning properly?

Exactly what happened to my truck. Came back from a short trip - less than 4 days - and my Maverick was going into deep sleep instantly after ignition off. (Related: wife's Bronco didn't do this. Both are '22 and I assume have similar Battery Monitoring Systems.) I checked the voltage numerous times over 3 days and was annoyed and frustrated, but then I reset the BMS which takes 10-15 seconds, and it's been fine for 3 weeks.

12.5V off is very strong. Somewhere around 12.0 - 11.8 is acceptable as a low range for a normal 12V battery when off.

Actually, both of those values seem a tad high. Maybe .2 to .3V higher than I'd expect. What did you use to measure?

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