Testing an Aux batt solution...

[Snakebitten]

You do realize that now the lowest resting voltage you will find your truck at is at the high-side of what everyone normally would see? ?

Sponsored

 

[hpwjr]

Yes, I realize that. It’s certainly a huge improvement. But why the change? I do use the 5 fan speed and the X2 battery shows almost totally full, so shouldn’t the voltage be around 13.1? The battery monitor app shows the main battery at 12.7. I was just wondering why the numbers dropped. They had been holding at 13.1.

 

[wolfman1]

Yes, I realize that. It’s certainly a huge improvement. But why the change? I do use the 5 fan speed and the X2 battery shows almost totally full, so shouldn’t the voltage be around 13.1? The battery monitor app shows the main battery at 12.7. I was just wondering why the numbers dropped. They had been holding at 13.1.

I've noticed the same thing. I had like 8 days straight of the battery holding steady at around 13, then all of a sudden it was 12.6 range, X2 said 75% charge remaining. Did a long drive this weekend, used the fan 5 trick to recharge the x2 battery and it was back to 100% full. Truck has been sitting for about 24 hours now and shows 13.2. Its going to be sitting for a few days so I'm definitely going to keep watching it.

 

[HammaMan]

Once the voltage dips down to 12.7 which happens after ~20% LFP depletion, both batteries begin getting used. I have a 30ah LFP. I believe your X2s are only 14ah? What happens as both batteries begin to get used, even on fan 5, the under-hood AGM charges much slower. Once parked the LFP begins to slowly top up the AGM giving the LFP less remaining overhead. It takes about 2 weeks for mine to get down to 12.8.

If your LFP isn't top balanced (if you can see individual cell voltages in your app, you can see if it's top balanced) it can't charge as full, as the highest cell voltage hitting 3.65v shuts down charging if the incoming current is higher than the clamping capability of its balance resistors (real easy to overwhelm them). LFPs can drift over time if not fully charged, especially if the cells that make them up aren't fully matched at the factory.

It shouldn't be too much of an issue w/ fan 5 as my voltage typically settles around ~14.3v and sitting at 14.2-3v should be enough to trigger the balance function w/out overvolting an individual cell unless there's a big imbalance. This is why I suggest the very first thing to be done w/ an LFP is to top balance using a benchtop power supply where the amperage can be turned down to around 20ma and the voltage set to 14.6v. I've seen it take 3 days to perform the initial top balance. You're not going to make much headway doing this in-truck while in parallel w/ the AGM.

Once a cell overvoltage occurs the logic of the exact BMS in your batt is unknown. Some require a little bit of energy to be used before it turns charging back on (typically the offending cell needs to get to 3.55 or 3.6v before any charging is allowed again. Snake top balanced his, so if you have the same batt as him and your truck isn't behaving like his, you may need to top balance the battery.

With a benchtop power supply you can see if a battery is fully charged by cranking up the amperage. Start w/ 13.8v, once incoming current tapers below 1a, start to turn up the voltage .1v at a time holding for 5 seconds per tick, if you can't reach 14.6v w/out the current stopping, it's not top balanced. At that point, set to 20ma of current, put voltage at 14.6v, and then use some type of brief load like a light bulb to get the batt to accept current if it won't at that set point. If 20ma is too much, it might be 15ma max balance current. If it trips, connect up a load briefly and turn down the amperage until it will continue to top balance w/out tripping cell overvoltage. There are 4 cells in the battery, if 1 of them hits 3.65v, but the other 3 are at 3.5v, the battery can't take but 14.2v before tripping due to cell overvoltage.

 

[Jmitchelltfo]

My X2 is 20ah.

Lowest I’ve seen is 12.98v one night when the temps got to -13°F, and I hadn’t driven my pickup for the past several days. The voltage climbed back to 13.1v on it’s own that morning after the sun warmed everything up a bit.

For those of you with lower voltage, are you running a parallel setup or did you replace your OEM battery with the X2?

 

[hpwjr]

I run mine in parallel. It’s always stayed up in the 13.1 range before until the last couple of weeks.

 

[wolfman1]

My X2 is 20ah.

Lowest I’ve seen is 12.98v one night when the temps got to -13°F, and I hadn’t driven my pickup for the past several days. The voltage climbed back to 13.1v on it’s own that morning after the sun warmed everything up a bit.

For those of you with lower voltage, are you running a parallel setup or did you replace your OEM battery with the X2?

I run mine in parallel, exactly like your post earlier in this thread.

With a benchtop power supply you can see if a battery is fully charged by cranking up the amperage. Start w/ 13.8v, once incoming current tapers below 1a, start to turn up the voltage .1v at a time holding for 5 seconds per tick, if you can't reach 14.6v w/out the current stopping, it's not top balanced. At that point, set to 20ma of current, put voltage at 14.6v, and then use some type of brief load like a light bulb to get the batt to accept current if it won't at that set point. If 20ma is too much, it might be 15ma max balance current. If it trips, connect up a load briefly and turn down the amperage until it will continue to top balance w/out tripping cell overvoltage. There are 4 cells in the battery, if 1 of them hits 3.65v, but the other 3 are at 3.5v, the battery can't take but 14.2v before tripping due to cell overvoltage.

The x2 app doesn't show individual cell voltages, but I did trickle-charge it at a very slow rate when I first got it. I will follow your guidance if I notice any strange behaviors in the future. Thank you!

 

[Snakebitten]

Mine had dropped off the 13.2V peak for resting voltage as well, I suspect from lots of NOT driving the truck, but moving it around a few times and multiple getting in/out of it during prep for upcoming trip.

Then I towed the RV 1200 miles to Florida, where it has been a generator for 2 RV's simultaneously for the last 3 days. That certainly brought the SOC back to 100%.
I don't know what the resting voltage is because I haven't turned the truck off for days. ?

The oem Motorcraft battery is still in it, (1008 days) even though I purchased a new H7 that I intended to swap in before I left. But I didn't get around to it. ??

I'm sitting in one of the RV's typing this, while the PID monitoring is live on my phone. (it's in the middle of a recharge cycle NOT in eco-idle mode)

My Powerboost parked behind the 2 RV's

My Godzilla out front.

The Class A is for the boss to wine/dine folks at the airshow. The rest of us peasants are support staff for the aircraft. ?

 

[UGADawg96]

Mine had dropped off the 13.2V peak for resting voltage as well, I suspect from lots of NOT driving the truck, but moving it around a few times and multiple getting in/out of it during prep for upcoming trip.

Then I towed the RV 1200 miles to Florida, where it has been a generator for 2 RV's simultaneously for the last 3 days. That certainly brought the SOC back to 100%.
I don't know what the resting voltage is because I haven't turned the truck off for days. ?

The oem Motorcraft battery is still in it, (1008 days) even though I purchased a new H7 that I intended to swap in before I left. But I didn't get around to it. ??

I'm sitting in one of the RV's typing this, while the PID monitoring is live on my phone. (it's in the middle of a recharge cycle NOT in eco-idle mode)

My Powerboost parked behind the 2 RV's

My Godzilla out front.

The Class A is for the boss to wine/dine folks at the airshow. The rest of us peasants are support staff for the aircraft. ?

Enjoy the SUN ‘n FUN, even if you are working!

 

[dochawk]

The oem Motorcraft battery is still in it, (1008 days)

I know it's April Fools Day, but you could have found something more believable to bait us with . . .

 

[Snakebitten]

I wasn't meaning to go for the world record for oem battery in a Gen14 F150 Powerboost. But I just might be the title owner at some point? ???

Honestly, I attribute it to Ford shipping me my truck immediately after it was assembled, along with the nerd in me to monitor it from the beginning, before Ford addressed the original anemic BMS charging strategy. I intervened every time it approached 12.3V resting, and charged it externally. So it has never suffered a serious injury. And now with the LFP support, it's fine. Especially if I drive it.

 

[Handle]

I wasn't meaning to go for the world record for oem battery in a Gen14 F150 Powerboost. But I just might be the title owner at some point? ???

Honestly, I attribute it to Ford shipping me my truck immediately after it was assembled, along with the nerd in me to monitor it from the beginning, before Ford addressed the original anemic BMS charging strategy. I intervened every time it approached 12.3V resting, and charged it externally. So it has never suffered a serious injury. And now with the LFP support, it's fine. Especially if I drive it.

Right there with ya…… built on 12/22/21…….picked up on 1/22/22 and installed the Bluetooth monitor In Feb ‘22 and generally charging it up when it slipped under 12.3 v. Today is day 1,166 since delivery and both batteries seem to be still going strong. ???

This thread has tempted me to switch out the Aux……but a world record…….hmmmmm?

 

[Snakebitten]

I WANT you to win!
And you will, because at some point I gotta install the new H7 I fetched, but haven't installed yet.

 

[wolfman1]

I WANT you to win!
And you will, because at some point I gotta install the new H7 I fetched, but haven't installed yet.

Will you continue to run the Lithium piggyback on your new H7?

 

[tsigwing]

Sponsored