LVB heavy use

[mq019]

Hey guys - I want to preface this by saying that I haven't had any issues at all with my LVB (knock on wood).

I use a BT OBDII sensor to keep track of info using the Torque app and noticed a couple of weeks ago that there was a data point for "LVB SOC", so I added that on a whim to just keep an eye on it.

I have noticed that the LVB seems to discharge quite a bit sometimes - It usually charges back up to 100% (or close) during driving, but I have seen several occasions where the truck has sat for a while (usually 6-12 hours) and it drops. I've seen it as low as 77%.

Seems to me that it shouldnt drop by almost 25% overnight. Is there really that much "stuff" going on in the truck when its "off" or is the battery really that small so a little bit off use results in a drop like that? Is there room for a larger (as in AH, not necessarily going with a battery with a huge footprint) battery and does it possibly make sense to upgrade?

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[Maquis]

Is the recall to replace the BMS sensor applicable to your truck and, if so, has it been completed? If not, you can be presented with erroneously low readings.

 

[mq019]

Is the recall to replace the BMS sensor applicable to your truck and, if so, has it been completed? If not, you can be presented with erroneously low readings.

Is that a recent recall? When my truck was in for the frunk issue a month or so ago, they told me that there were no open recalls.

 

[RickLightning]

You cannot put in a larger battery, BMS won't like it.

77% is fine.

BMS is not a recall, it is a CSP. https://www.f150lightningforum.com/...-150-lightnings-bms-sensor-replacement.17900/

 

[Green1]

The battery in these trucks is minuscule, and yes, there is some draw, especially if you are using the app regularly, or have any other services which try to ping the vehicle.
I'm not pleased with the overly strict BMS that won't let you put a bigger battery in either, because I have some special use cases which cycle the existing battery a lot harder than I'd like. Ford also specifically says not to put a second battery in for accessory loads, but I may ignore them on that one just to save the primary LVB some wear and tear.

 

[Henry Ford]

If you remove "LVB SOC" from Torque your problem will be solved.

 

[mq019]

You cannot put in a larger battery, BMS won't like it.

77% is fine.

BMS is not a recall, it is a CSP. https://www.f150lightningforum.com/...-150-lightnings-bms-sensor-replacement.17900/

Thanks for the info from that BMS thread - it looks like that's not an issue as my serial number doesnt match the CSP.

 

[Adventureboy]

If you leave your OBDII active it may be keeping modules alive that would normally shut down 10 minutes after you shut the truck off causing higher than normal LVB drain. I used an independent monitor to track it and it drops for the first hour or so, then drops at a lower rate since it keeps things like the modem active for FordPass. If you leave it for multiple days, it will drop to 40-50% and go into deep sleep mode at which time Fordpass won't work since it shuts down the modem. It will charge the LVB from the HVB in that scenario but will stay in deep sleep until you start the truck.

It works much better with the updates last year and with the CSP if you need it. The CSP for the BMS is needed if you get battery drain messages regularly. It's a simple replacement of the little black module on the negative terminal of the LVB. More here: https://www.f150lightningforum.com/forum/threads/battery-management-recall.19399/#post-388664

 

[mq019]

Thanks guys - sounds like its operating as designed (even if it is a poor design and could use a little larger battery). I'm not going to worry about it. It generally never sits for more than a day without getting driven, and when I'm on vacation for a couple of weeks next month, I'll leave it plugged in while I'm gone, so it should be fine.

 

[Adventureboy]

Thanks guys - sounds like its operating as designed (even if it is a poor design and could use a little larger battery). I'm not going to worry about it. It generally never sits for more than a day without getting driven, and when I'm on vacation for a couple of weeks next month, I'll leave it plugged in while I'm gone, so it should be fine.

Plugged in or unplugged won't matter to the 12v battery. Not the best design, but the 12v battery will still deplete and go through the same cycle since the 12v only charges while the HVB is charging. Once your HVB charge cycle ends on the first day it will discharge, deep sleep and recharge, then continue to discharge/recharge over and over every few days.

Here is what I do:

• A week or less - just leave it unplugged with HVB SOC somewhere around 30-70%. There is no need to leave it plugged in. It will use very little HVB if any at all. I would even do this if I need to leave it at the airport for 2-3 weeks. It will take care of itself with little impact to the HVB.
• More than a week - I leave it unplugged with HVB SOC around 30-60% and if I have the option, I plug in a 12v AGM trickle charger on the 12v battery to keep the 12v from cycle charging over and over.
• More than a month - This is per owner's manual for long-term storage. Leave it unplugged with HVB SOC around 30-50% and disconnect the negative terminal on the 12v battery (this requires a garage so you can leave the frunk unlatched or you will need to jump the truck to get it open.) Frankly, plugging it in and setting your SOC to 40%, and plugging in a trickle charger on the 12v would probably work better for longer-term storage.

In any case, it is better to leave the EVSE disconnected so you aren't keeping the HVB at the top of the energy band since this degrades the HVB faster albeit only slightly faster.

 

[CyclopsThere]

If you leave your OBDII active it may be keeping modules alive that would normally shut down 10 minutes after you shut the truck off causing higher than normal LVB drain. I used an independent monitor to track it and it drops for the first hour or so, then drops at a lower rate since it keeps things like the modem active for FordPass. If you leave it for multiple days, it will drop to 40-50% and go into deep sleep mode at which time Fordpass won't work since it shuts down the modem. It will charge the LVB from the HVB in that scenario but will stay in deep sleep until you start the truck.

It works much better with the updates last year and with the CSP if you need it. The CSP for the BMS is needed if you get battery drain messages regularly. It's a simple replacement of the little black module on the negative terminal of the LVB. More here: https://www.f150lightningforum.com/forum/threads/battery-management-recall.19399/#post-388664

This was going to be my thought. Is OP leaving their OBDII dongle plugged in? I've seen it cause crazy battery drain in other cars I've owned and been lazy with. I would physically remove it each time I powered the truck off and see if that's the culprit.

 

[Maquis]

(this requires a garage so you can leave the frunk unlatched or you will need to jump the truck to get it open.)

The truck and frunk can both be unlocked/opened manually.

 

[Adventureboy]

The truck and frunk can both be unlocked/opened manually.

True - good catch. They kept the key for the Lightning (thank you Ford). It is the wife's MME that I can't get into without the external battery jump - what's up with that?

 

[Maquis]

True - good catch. They kept the key for the Lightning (thank you Ford). It is the wife's MME that I can't get into without the external battery jump - what's up with that?

Right, the MME and Lightning have several differences that seem odd. This and the one-time charge limit only in the Lightning. The extra climate controls in the app. I’m sure there are others.

 

[invertedspear]

Right, the MME and Lightning have several differences that seem odd. This and the one-time charge limit only in the Lightning. The extra climate controls in the app. I’m sure there are others.

It's weird to me, because the Lightning philosophy is "F150, but electric" yet we have more things on our dashboard specific to EVs, battery and engine temps, the ability to show draw and regeneration. Just a lot of EV specific things. The MME is "Ground up EV platform" but then they go out of their way to hide the EV experience. Want to see battery draw or regen, tough luck, you get a near meaningless brake coach. Battery or motor temp? Nope. Just overall the experiences are weird given the philosophy.

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