H8 Battery Upgrade May Not Quite Be the Solution That I Hoped For

[ReverendQ]

Yup - installing my H8 fixed all of my electrical gremlins - no more warnings, etc. All issues were resolved. Loved it. Never put my truck on a battery charger/maintainer again.

Then - and out of chance - I started using the OBD II PIDs. ONLY THEN did I see my low SOC.

Are you taking the OBD reader off the bus when its sitting? It does take power. Any other loads i.e. dash cameras? Key fob close by? Enabling WiFi and cellular for OTA?

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[FirstFord]

Are you taking the OBD reader off the bus when its sitting? It does take power. Any other loads i.e. dash cameras? Key fob close by? Enabling WiFi and cellular for OTA?

It is now my understanding (from another contributor's post in this thread) that the OBD II port powers down (as do the other modules) after 60 ~ 90 minutes.
Dash camera: yes, but only powered when ignition is on.
The only key fob is in my pocket, so, no other fobs laying around.
Yes, Wi-Fi and cellular are enabled for OTAs. But I wouldn't think that those functions would use that much power. My cell phone has the same two functions active, and it can last for days on just a 4500mAh battery. The H8 is a 95 Ah, which (I think) is 95,000 mAh.

To my knowledge, the components to receive OTAs and the constant "searching for an active key fob" are the only energy using components that are active. But yes, I get your point.

By upgrading to an H8 size battery, my assumption (hope?) was that I would be able to return to the world of my old trucks - the ones that could sit for many months at a time, and still start up without an issue and have no electrical issues either. But to @PaulGrun 's (indirect) point, I wasn't monitoring the SOC on those old trucks either.

 

[Porpoise Hork]

Unfortunately there isn't a modern car/truck out there that will allow you to go for months at a time anymore. There's just too many little electric vampires sipping on the battery. Even with the increased Ah capacity of the H8 and increasing the SOC setting to 100% you're probably only going to get at best 2-3 weeks before the truck goes into deep sleep. You can put a 12v bluetooth voltage monitor on it which would allow you to keep an eye on the actual voltage from your phone after key off however this too would while minimal put a slight parasitic drain on the 12v battery. Upside is you'd know if the battery were getting low and required charging etc.

 

[Sig Oris]

Could've sworn H8 was not meant for PBs. I think others have said it wouldn't fit. Interesting. It's not that uncommon to see vehicles not in constant use be put on battery maintainers. I have an onboard tender on mine that's quick and easy to plug in. Which tender do you have? I have a kit that utilizes a male outlet on the bottom of the front bumper (so it's a quick & easy plug/unplug without popping the hood, but I haven't installed it yet). Which tender do you have?

believe he stated an EB

 

[ReverendQ]

It is now my understanding (from another contributor's post in this thread) that the OBD II port powers down (as do the other modules) after 60 ~ 90 minutes.
Dash camera: yes, but only powered when ignition is on.
The only key fob is in my pocket, so, no other fobs laying around.
Yes, Wi-Fi and cellular are enabled for OTAs. But I wouldn't think that those functions would use that much power. My cell phone has the same two functions active, and it can last for days on just a 4500mAh battery. The H8 is a 95 Ah, which (I think) is 95,000 mAh.

To my knowledge, the components to receive OTAs and the constant "searching for an active key fob" are the only energy using components that are active. But yes, I get your point.

By upgrading to an H8 size battery, my assumption (hope?) was that I would be able to return to the world of my old trucks - the ones that could sit for many months at a time, and still start up without an issue and have no electrical issues either. But to @PaulGrun 's (indirect) point, I wasn't monitoring the SOC on those old trucks either.

Indeed, to increase Aux Battery (system) capacity for my Powerboost, and to increase charge/discharge rate of the main 12VDC under hood battery I did this, (1) Auxiliary Battery Problem? | Page 3 | F150gen14 -- 2021+ Ford F-150, Tremor, Raptor Forum (14th Gen) | News, Owners, Community, Discussions . It keeps it pretty much at 100% SOC when combined with the Fan 5 trick while driving. Something to consider is that the LiFePO quick charge and discharge capability maintains the under hood battery faster than AGM battery solutions do.

And since I have adequate sunshine and the truck is parked outdoors for a bit during some of my escapades, I implemented this (1) LensunSolar Hood Solar Panel F-150 Powerboost BAP/Tremor Hood Installation | F150gen14 -- 2021+ Ford F-150, Tremor, Raptor Forum (14th Gen) | News, Owners, Community, Discussions . In SoCal even parked outside for weeks I remain at 100% SOC.

These seem to be about the only ways to keep a gizmo'd up truck (or car) ready to go.

 

[Savannah Power]

Buy an X2 brand H7 at Batteries & Bulbs, look for discount coupons up to 30%. Higher cranking amps, hybrid design with deep cycle resistance, AGM, and higher voltage than regular batteries.

 

[Chirpy]

Small solar chargers for the win!

 

[Calson]

After replacing the battery 3 times in 3 years on my 2022 truck I found that there are parasitic draws that occur when the ignition is in theory off. Quite a number of youtube videos that cover the process required to locate the problem part. On on video it took the mechanic two days of constant monititoring to determine first that something after a number of hours there would be a sudden spike in amp draw, and second to determine on this Ford vehicle that it was the alternator. This mechanic had the tools and expertise and time to find the problem and correct it for this one customer.

After 3 years of having the least reliable vehicle I have ever owned I decided to sell the truck. Problem solved.

 

[thebestbear]

If I understand the main issue here is battery draw during long sit times. Why not just get a quick disconnect battery switch? Seems a lot easier than trickle charging all the time.

 

[FirstFord]

There has been a lot of good input from forum members, and I particularly learned some things from @Porpoise Hork and @PaulGrun - thanks everyone for your input.

Update - yet another new wrinkle: After sitting on the NOCO 10A battery maintainer/charger for 4 solid days (after being on it for 20 hours prior to that), I unplugged it from the charger because I needed the truck. I started the truck; it was charging at 14.2V, and showed SOC at 65%!!!!! WTF????

Okay, I need help here, because I'm not smart enough to figure this one out!

 

[Porpoise Hork]

The BMS can get a little crotchety at times. Mine has done the same thing when it's been on the charger for an extended period of time. I have had it show 85% SOC after being on charge for 12 hours, and REFUSE to change while driving around for a solid 90 minutes with the fan on 5 and pumping 14.4v into it the entire time. Then shut it off and came back out a few hours later and it finally showed 100%. I have also had it sitting at 70% then after driving for 20+ minutes see it had jumped to 100%.

In your case, the BMS might have not been able to properly detect the actual SOC if the negative charge cable was connected directly to the battery terminal and not to a body ground or the post behind the BMS module that's bolted to the battery. If so it will show the last known level and not reflect the charge that you put into it. I'd suggest performing the BMS reset then let it sit overnight w/o the charger on it and then check it after 8-10 hours so it can properly update itself. After that make sure to place the negative clip on the battery's body ground or the post behind the small module on the negative terminal so the BMS sensor can detect the voltage being put into the battery.

 

[FirstFord]

The BMS can get a little crotchety at times. Mine has done the same thing when it's been on the charger for an extended period of time. I have had it show 85% SOC after being on charge for 12 hours, and REFUSE to change while driving around for a solid 90 minutes with the fan on 5 and pumping 14.4v into it the entire time. Then shut it off and came back out a few hours later and it finally showed 100%. I have also had it sitting at 70% then after driving for 20+ minutes see it had jumped to 100%.

In your case, the BMS might have not been able to properly detect the actual SOC if the negative charge cable was connected directly to the battery terminal and not to a body ground or the post behind the BMS module that's bolted to the battery. If so it will show the last known level and not reflect the charge that you put into it. I'd suggest performing the BMS reset then let it sit overnight w/o the charger on it and then check it after 8-10 hours so it can properly update itself. After that make sure to place the negative clip on the battery's body ground or the post behind the small module on the negative terminal so the BMS sensor can detect the voltage being put into the battery.

Your story of BMS getting "crotchety" is, on the one hand interesting, but on the other hand, is beyond my weirdness comprehension level.

For the sake of clarification, I use a wire harness that is hidden behind the grill so that I don't have to open the hood every time to hook it up to the charger - the negative is grounded to the body, not to the battery, or immediately after the BMS.

Right, wrong, or indifferent, my current frame of mind (subject to change) is to go back to not even putting it on the battery maintainer. The data that I get for guidance in decision making strikes me as either unreliable, OR, with so many caveats attached, it isn't worth chasing. And again, prior to starting this thread, I wasn't experiencing "issues" before, during, or after - I was just alarmed at seeing 45% SOC when I started viewing PIDs. Rather maddening, really....

 

[Eskram]

I've had the same issue, where extended charging and driving has barely raised the SOC. I chalked it to BMS weirdness.

Charging both fully (if you have an aux battery) externally to 100% and resetting the BMS helped in my case.

 

[PaulGrun]

There has been a lot of good input from forum members, and I particularly learned some things from @Porpoise Hork and @PaulGrun - thanks everyone for your input.

Update - yet another new wrinkle: After sitting on the NOCO 10A battery maintainer/charger for 4 solid days (after being on it for 20 hours prior to that), I unplugged it from the charger because I needed the truck. I started the truck; it was charging at 14.2V, and showed SOC at 65%!!!!! WTF????

Okay, I need help here, because I'm not smart enough to figure this one out!

Again, keep in mind that the SOC you are being shown is not reliable until the BMS has had a chance to re-calibrate following an extended rest period (like overnight).
In your case, you took it off the charger and got wacko readings, which is not surprising to me.
Remember, between re-calibration events the BMS is interpolating what it thinks the SOC should be. But yours was sitting on a charger for a couple of days so it’s anyone’s guess what the actual SOC is, much less what the BMS thinks it is.

Frankly, in this case, you might be better off looking up the battery manufacturers tables, estimating the age of the battery, measuring the current “resting” voltage then using the tables to look up the actual SOC.

But that probably won’t tell you much either since you’d need to let the battery settle overnight and you would need a very high precision voltmeter (because the SOC vs V(rest) curve is very flat so we’re talking about detecting probably microvolt differences).

So again, I’m gonna claim that as consumers, there is virtually nothing to be gained by looking at the OBD PID. It’s simply not intended to be used as a tool to monitor battery health, and certainly not by watching short term swings.

 

[FirstFord]

So again, I’m gonna claim that as consumers, there is virtually nothing to be gained by looking at the OBD PID. It’s simply not intended to be used as a tool to monitor battery health, and certainly not by watching short term swings.

1000 years ago, in the 1960s and 1970s, I thought I was a halfway decent "shade-tree mechanic". I may have thought too highly of myself. Plus, these trucks are technological marvels compared to what I am used to. I had a steep technology learning curve when I I ordered my '22 Lariat (replaced a '00 Silverado). But situations like this make me shake my head, and think, "Stop it. Just leave it alone. If it doesn't start, then put jumper cables on it or a battery charger on it".

In other words, in my attempt to become more current, I think I have actually hindered myself....

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