Spidergears
Well-known member
- Thread starter
- #1
So, like many, I've been following the thread that @FirstFord started about installing an H8 sized battery. It's a good thread if you haven't read it.
I like many have been dealing with the dreaded power savings mode and having features disabled. It's really annoying at night when the interior lights won't come on when getting out of the truck. The truck never had a hard time cranking though.
After reading lots of threads and comments, I decided to see what the obdii data said was going on and see if I could draw any conclusions, or at least have some fun nerding out.
First, a few details about my truck. It's just a 3.5 ecoboost, not a powerboost, and has the start/stop deleted from the factory. It does get driven most days, but the longest is like 3-4 times a week I drive it about 15-20 minutes twice a day. I've been having the power savings issue for a few months. Even after trips that took near 3 hours, I the issue would return pretty quickly.
I had my truck at the dealership recently for recalls and asked them to look into the issue. The battery tested good, so without deeper diagnosis, they weren't able to tell me anything more. Interestingly enough, since I got my truck back, it hasn't gone into power save mode.
So, I used my obdii adapter and started logging parameters like engine rpm, battery charge mode (which never showed a value), the battery current, battery state of charge, and a few others.
When I was just getting my footing looking at the data, I first noticed my battery was only showing 35% state of charge, but it was charging relatively quickly and hit 50%. It makes me wonder what the parameters are to induce the power savings mode.
Anyhow, I finally got the enough parameters logging and did 2 runs.
Here's the first one.
From the time I crank the truck to the time I shut it off, I'm correlating amps to state of charge. You can see the amperage starts off really high, but then starts coming down quickly. You'll also note that as the battery charges, the amperage goes down. Not too surprising, but what's surprising to me is the low rate at which it is charging. It's hard to see in the chart, but from about 19 minutes onward, it's only pushing 2-3 amps.
Here's the second run.
Again here you can see the amperage start off really high but goes down quickly. By minutes 6 it was down to 3 amps, but it was also already over 50% SOC. By minute 15 was only pushing 1-2 amps, and by minute 23 it was pushing 1 amp or less.
One thing that you can't see here, and I only have a data point of 1 at the moment, is the state of charge went down about 7% over night. So, if I'm not charging at least that much during a day, I'm at a net loss.
For fun, I decided to try out some AI to analyze my csv to determine the factors that result in a slower charge rate when the vehicle is running. It concluded that:
- There is a moderate negative correlation with the vehicle battery state of charge and the current, suggesting as the state of charge increases the charge rate tends to decrease.
- There is a weak correlation between engine rpm/gear and the charge rate.
- It also thinks there is only like 27% of the variability in the battery current can be explained by the data I provided.
So, all of this was fun and interesting, but lead me to the same result as most of you have already figured out. I just need to charge my battery on occasion because while the alternator is totally capable of keeping the battery charged, the algorithm appears to be severely limiting the charge rate. There's nothing wrong with my battery, nothing physically wrong with my truck that can be fixed.
I also get that there's a ton of other factors here that could be contributing. Perhaps in the summer this looks totally different. Perhaps the next software update will change this algorithm. I would be curious to see if engine load has anything to do with it. Like I could see if you were pulling a trailer, or climbing a hill, cut the current so you can prioritize power to the drive-train. But if we're just saving fuel, I wish I could override that.
Anyhow, thought I would share.
I like many have been dealing with the dreaded power savings mode and having features disabled. It's really annoying at night when the interior lights won't come on when getting out of the truck. The truck never had a hard time cranking though.
After reading lots of threads and comments, I decided to see what the obdii data said was going on and see if I could draw any conclusions, or at least have some fun nerding out.
First, a few details about my truck. It's just a 3.5 ecoboost, not a powerboost, and has the start/stop deleted from the factory. It does get driven most days, but the longest is like 3-4 times a week I drive it about 15-20 minutes twice a day. I've been having the power savings issue for a few months. Even after trips that took near 3 hours, I the issue would return pretty quickly.
I had my truck at the dealership recently for recalls and asked them to look into the issue. The battery tested good, so without deeper diagnosis, they weren't able to tell me anything more. Interestingly enough, since I got my truck back, it hasn't gone into power save mode.
So, I used my obdii adapter and started logging parameters like engine rpm, battery charge mode (which never showed a value), the battery current, battery state of charge, and a few others.
When I was just getting my footing looking at the data, I first noticed my battery was only showing 35% state of charge, but it was charging relatively quickly and hit 50%. It makes me wonder what the parameters are to induce the power savings mode.
Anyhow, I finally got the enough parameters logging and did 2 runs.
Here's the first one.
From the time I crank the truck to the time I shut it off, I'm correlating amps to state of charge. You can see the amperage starts off really high, but then starts coming down quickly. You'll also note that as the battery charges, the amperage goes down. Not too surprising, but what's surprising to me is the low rate at which it is charging. It's hard to see in the chart, but from about 19 minutes onward, it's only pushing 2-3 amps.
Here's the second run.
Again here you can see the amperage start off really high but goes down quickly. By minutes 6 it was down to 3 amps, but it was also already over 50% SOC. By minute 15 was only pushing 1-2 amps, and by minute 23 it was pushing 1 amp or less.
One thing that you can't see here, and I only have a data point of 1 at the moment, is the state of charge went down about 7% over night. So, if I'm not charging at least that much during a day, I'm at a net loss.
For fun, I decided to try out some AI to analyze my csv to determine the factors that result in a slower charge rate when the vehicle is running. It concluded that:
- There is a moderate negative correlation with the vehicle battery state of charge and the current, suggesting as the state of charge increases the charge rate tends to decrease.
- There is a weak correlation between engine rpm/gear and the charge rate.
- It also thinks there is only like 27% of the variability in the battery current can be explained by the data I provided.
So, all of this was fun and interesting, but lead me to the same result as most of you have already figured out. I just need to charge my battery on occasion because while the alternator is totally capable of keeping the battery charged, the algorithm appears to be severely limiting the charge rate. There's nothing wrong with my battery, nothing physically wrong with my truck that can be fixed.
I also get that there's a ton of other factors here that could be contributing. Perhaps in the summer this looks totally different. Perhaps the next software update will change this algorithm. I would be curious to see if engine load has anything to do with it. Like I could see if you were pulling a trailer, or climbing a hill, cut the current so you can prioritize power to the drive-train. But if we're just saving fuel, I wish I could override that.
Anyhow, thought I would share.
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