Subaru XV Crosstrek Forums banner

161 - 171 of 171 Posts

·
Registered
'18 and '19 Crosstrek Limiteds
Joined
·
6,909 Posts
Discussion Starter #161
Well, it was 12.4V this morning after being out all day in the sun yesterday, short trips (Costco run, etc.) but parked in the sun most of the day, and the dash cam was on all night. So the solar panel and AGM combo is certainly working. Just need to figure out why it's draining so much when it's parked underground for a couple of days. Fortunately, I wired the cam into the solar panel's regulator so it shuts off the cam below 12V.

The specs for the cam claim 380mA but that's with Wi-Fi off. I like having the Wi-Fi on because we have Wi-Fi in the garage (no security cams but Wi-Fi, go figure) and can download the video without having to pull the microSD card, which is extremely fiddly.

The behemoth, as @dwasifar calls it, LOL, is 20Hr 65Ah. My battery knowledge is about at its limit here - assuming the cam with Wi-Fi on is 700mA (pure speculation), how long should I expect to be able to run it from the battery before the battery drops below 12V (25% charge)? Of course, there's other stuff going on when the car is supposedly "off" and the battery won't start out fully charged even under the best conditions.

Next time I have custody I'll try hooking up the Watt meter...
 

·
Registered
Vancouver, BC, Canada CGK 2018 Ltd EyeSight
Joined
·
1,919 Posts
Our HOA is pretty dysfunctional and there's no appetite for spending money unless something is broken and even then it takes forever - one of the water heaters has been out since August. We bring up cameras at every meeting. I'm less concerned about what might happen to the car in the garage, though. More concerned about packages being stolen, etc. I like the idea of parking mode for when the car is parked on the street or in a supermarket parking lot and gets scraped or whatever.
Well, if you just use it for short times, you should be OK. It is the repeated overnight usage that could drain the battery.
 

·
Registered
Vancouver, BC, Canada CGK 2018 Ltd EyeSight
Joined
·
1,919 Posts
Not sure how you have the cam wired to your car. But it's presence even though drawing very little power could cause other car electronics in the car to wake up and stay awake using power.

I know on the Ascent forum there was considerable discussion about what happens if you leave the tail gate open (as when at tailgate party or whatever). Even though the lights shut after so many minutes, the car electronics remain active and draw a steady 4 amps. As a result the car battery would eventually be run down. So hard to know exactly what all can cause a battery drain...
 

·
Registered
'18 and '19 Crosstrek Limiteds
Joined
·
6,909 Posts
Discussion Starter #164
Not sure how you have the cam wired to your car. But it's presence even though drawing very little power could cause other car electronics in the car to wake up and stay awake using power.

I know on the Ascent forum there was considerable discussion about what happens if you leave the tail gate open (as when at tailgate party or whatever). Even though the lights shut after so many minutes, the car electronics remain active and draw a steady 4 amps. As a result the car battery would eventually be run down. So hard to know exactly what all can cause a battery drain...
Interesting...

The solar panel regulator is connected to an always on unused fuse connection in the driver side panel (can't remember which, without searching for it) and the cam is connected to the device output of the regulator (so it will be shut off if the battery drops below 12V). Not sure of the logic, exactly, but I assume that when the panel is generating power it's charging the battery and powering the cam, and when it's not generating power, the battery is powering the cam (until the battery drops below 12V).

I'm really curious now to hook up the Watt meter and see watt's really going on... 😸
 

·
Registered
'18 and '19 Crosstrek Limiteds
Joined
·
6,909 Posts
Discussion Starter #165
I did some more tests this morning. The voltage at the battery with nothing on in the car was 12.41V. The car had been parked in the sun all day yesterday and then the cam was on overnight. So the new battery is taking up charge very well from the solar panel, when it can get it.

Then I hooked up the Watt meter to the camera and it fluctuated between 5 - 6W depending on what it was doing. So, with Wi-Fi on, it's not much more than the 380mA in the specs with Wi-Fi off. Perhaps 450mA on average.

At some point, I'll test the total drain from the car over a period of time but it seems that just the cam would discharge a fully charged 65Ah battery to 50% in a couple of days, unless it was parked in the sun.
 

·
Registered
Joined
·
45 Posts
Your math is correct re: a 450mA draw for several days. One thing to keep in mind is that at some point, your AGM won't have enough reserve to crank that engine. I'm a ham radio operator, use solar power with dedicated regulators, etc. An AGM battery generally requires more than 35% of its rated capacity (or so) to be able to supply the 23 amps my radio draws at full power. Resting voltage can be fine, but once it reaches a certain point of discharge, it can't suppply more than the 10.98 volts the radio requires and the radio will cut out. If that happens, I have to reduce the output power of my radio until the battery charges back up. Realistically, a 20Ah battery can supply about 10Ah of useful power. That's why I have switched to a LiFePO4 battery. It's lighter by far, smaller, and has more usable power per stated Ah capacity than an AGM. For my cars, I'll switch to AGM batteries when the time is right. I've done well with these in the past (Optima).
 

·
Registered
'18 and '19 Crosstrek Limiteds
Joined
·
6,909 Posts
Discussion Starter #167
Thanks! The best I can think of is to set the shut off at the highest voltage possible so it won't drain the battery too much. Probably means it won't be on in parking mode all the time, unless it's parked in the sun.
 

·
Registered
'18 and '19 Crosstrek Limiteds
Joined
·
6,909 Posts
Discussion Starter #168 (Edited)
So, after a few more days of testing, all I've accomplished is to confuse myself...

OAK's "weekend" is Sunday/Monday (she works Saturdays) and even when she was at work on Saturday with the car parked outside all day there wasn't much sun. We didn't use the car on Sunday (so it was parked undergound) and this morning, Monday, the battery was down to 11.79V at the battery terminals with nothing on in the car. The cam had already shut off due to low low voltage but the car started at the first touch.

On Sunday I hooked up a Watt meter, inline from the battery terminals, to try to figure out what's going on. At the time, the battery was 12.08V with no load. The drain was over 40W with the car woken up (when you approach it with a fob and open a door). With the car closed up and locked and the fob far away, and the car asleep, the drain eventually dropped to only 0.2W on average. I expect there will be a spike when the fuel evaporation system kicks in but I didn't wait that long.

To eliminate the solar panel wiring and controller I hooked that up first and there was no change. However, with the dash cam on and in parking mode, it was fairly consistent at around 6W. No special wiring - at this point it's still just plugged into a cig adaptor socket, and I got similar readings when testing it directly connected to the Watt meter. That's also consistent with the power consumption in the manual and specs. Turning off the Wi-Fi on the cam appeared to make little difference. With or without Wi-Fi it fluctuates between 4.7 and over 6W.

Some questions:

1. I was shocked that the car started so well with 11.79V recorded at the terminals with nothing else on in the car (and only a 0.2W drain from my previous tests). It's about 60F here today. Some battery voltage charts I've seen for AGM batteries say this voltage should mean fully discharged but, clearly, that's not the case. Anyone have any reliable info/charts to determine the state of charge of an AGM battery from the voltage (I realize it's an approximation).

2. I'm wondering if the cig port adaptor that came with the cam may be part of the problem. Anyone have any suggestions for alternatives that may be more efficient? I forgot to check the output voltage and OAK is out in the car but I'm guessing 3-5v.

3. The solar panel controller that came with the panel seems to be working OK but I'd like to be able to shut off the cam at a higher voltage than the regulator allows. Ideally, specify the actual voltage so I can find a balance between not draining the battery too much and maximizing the time the dash cam can be in parking mode. Any suggestions?

4. What I really don't understand is why our Ring doorbell, with a Li-ion battery about the size of a matchbox, can do essentially the same thing for a month (albeit with only one camera) whereas the Blackvue cam drains a high end car battery in a few days. Any ideas?
 

·
Registered
'18 and '19 Crosstrek Limiteds
Joined
·
6,909 Posts
Discussion Starter #169
Well, it started this morning after hardly being used all "weekend". The AGM battery seems pretty resilient.
 

·
Registered
'18 and '19 Crosstrek Limiteds
Joined
·
6,909 Posts
Discussion Starter #170
Around 12.4V this evening, after a 5 mile commute, each way, and being parked in the sun all day...
 

·
Registered
'18 and '19 Crosstrek Limiteds
Joined
·
6,909 Posts
Discussion Starter #171
Another experiment:

I reconfigured the dash cam to only be connected to the ACC power, so it hasn't been in park mode for a few days (since Sunday). Already, the new Odyssey battery is back up to almost 12.7V, just pottering around West LA and being parked in the sun some of the time.

I'm very impressed with how well the new battery takes up charge. Just have to figure out how to handle the drain from the dash cam in parking mode.
 
161 - 171 of 171 Posts
Top