Anyone Use LiFePO4 STARTER Battery with Dashcam Hardwired?

[AEMontoya]

I'd love to hear about anyone's experience using a LiFePO4 (LiFe) STARTER battery to power a dashcam in parking mode vs typical LA, AGM, or dedicated dashcam batteries.

I assume that the following characteristics of LiFe starter batteries will create a unique experience when it comes to dashcam usage:

1) BMS-regulated voltages of between 13.2 and 12.5 V
2) Relatively high cycle life
3) Relatively quick re-charge rate
4) Relatively flat discharge curve that drops off rapidly after ~12.5 V
5) The ability to use ~90% capacity vs ~50% capacity, meaning that a 60 Ah LiFe with same form factor as 80 Ah AGM/LA actually delivers an AGM/LA equivalent of ~100 Ah
6) Relatively high energy density and cranking power
7) Operating temperatures of between ~20 F (-7 C) to ~115 F (46 C)
8) They cost more, but have a longer cycle life (I am less concerned about price and more concerned about performance here)
9) Relatively light weight (although, this doesn't really matter when it comes to dashcam usage)

I'd love to hear about anyone's experiences using such starter batteries to power their dashcams in parking mode.

 

[GPak]

On Dash Cam operation:
Dash Cam doesn't care where it gets power from, it doesn't need regulated voltage, it has it's own voltage regulator, for example anything in a range of 11.8V-18V will work for Viofo HK4 hard-wire kit.
Note, that 11.8V-12.4V is the cut-off voltage range for the HK4, which is somewhat higher than about 10V-11V recommended for LFP, meaning you will not get full capacity out of LFP, which is a good thing, since you still need to start the car.
I think most other Dash cams brands are similar.
Parking longevity depends on Battery usable capacity, so if LFP battery with all the limitations can provide more capacity til cut-off by hard-wire kit, then yes, you will have longer parking recording.

On LFP Battery to be used as a Starter Battery:
This is not that strait forward:
On 7) - LFP should not be charged at sub-freezing temperature, especially at high C rates, which is likely the case for in-car charging.
If the battery is located under the hood, I would not consider an LFP, if it is located inside the cabin or in the trunk, then maybe, but only with a purposely designed/programmed BMS.
See this video:

 

[AEMontoya]

On Dash Cam operation:
Dash Cam doesn't care where it gets power from, it doesn't need regulated voltage, it has it's own voltage regulator, for example anything in a range of 11.8V-18V will work for Viofo HK4 hard-wire kit.
Note, that 11.8V-12.4V is the cut-off voltage range for the HK4, which is somewhat higher than about 10V-11V recommended for LFP, meaning you will not get full capacity out of LFP, which is a good thing, since you still need to start the car.
I think most other Dash cams brands are similar.
Parking longevity depends on Battery usable capacity, so if LFP battery with all the limitations can provide more capacity til cut-off by hard-wire kit, then yes, you will have longer parking recording.

On LFP Battery to be used as a Starter Battery:
This is not that strait forward:
On 7) - LFP should not be charged at sub-freezing temperature, especially at high C rates, which is likely the case for in-car charging.
If the battery is located under the hood, I would not consider an LFP, if it is located inside the cabin or in the trunk, then maybe, but only with a purposely designed/programmed BMS.
See this video:
...

Thank you for these insights. I think that, in terms of a dashcam having its own regulator that only allows for a min voltage of 11.8V, there may not be concern, as the starter batteries that I see have a BMS that already cuts off voltage at around 12.5 V. This brings up an interesting point that I did not previously consider: Even though LFP batteries have the ability to utilize ~90% of their capacity in theory, since starter batteries have a BMS that limits the useable voltage range between about 12.5 and 13.2 V, the capacity that they utilize in practice may be closer to 55%, which is very similar to an AGM/LA battery. See table below. Hence, perhaps LFP batteries don't allow for more parking mode time after all, at least not from the perspective of useable capacity. Their quicker charging rates, ability to withstand more cycles, etc are still potential positives when used for parking mode as compared with AGM/LA batteries.



Good point about charging at below freezing levels and how that relates to where the battery is located in the vehicle. In my case, personally, I live in the Bay Area, CA. Thus, below freezing, and even at freezing, temperatures are not a concern for me. But the point it still relevant for many, of course. Additionally, I do believe that these starter batteries have built-in BMS that regulate temperature and charging rates so as to mitigage a fair amount of subzero effects, within reason.