USB power bank as a backup to the car battery

Steven Seagal

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I purchased a Blackvue DR900s 2CH after being hit in a parking lot. I'm really looking forward to the parking mode but of course have concerns about the battery drain. I plan on hardwiring with the Power Magic Pro and setting the voltage to 12.5v. From reading, I see the general consensus is that using a USB Li Ion battery is frowned upon based on fire risk due to thermal management. What I want to do is have the dashcam use the power from the car's battery first, and when it reaches the lower voltage limit, switch over to the USB battery. I want to have a cable out so that I can plug in the USB battery as needed. My motivation here is that it uses the safest way to power the camera (car battery) a majority of the time and USB only as needed.

I would only really use this for parking overnight when the temperatures are colder. During the daytime I would not plug in the USB and let it use the car battery. I'll charge the USB battery at my desk or home when its convenient. Is there something that exists that allows this switch?
 

jokiin

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Too many ¯\_(ツ)_/¯
the Blackvue is 12v, won't work from a regular USB power bank, 12.5v cutoff might give you an hour or so of parking mode if your battery is healthy

this is why they sell the auxiliary batteries, B124 is the model number (I think), it's the same as the Cellink Neo
 
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Steven Seagal

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What about the USB jump starter batteries with the 12V out?
 

EsQueue

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While you can get almost any 5 volt usb backup battery to run the a 12 volt camera via boosters, the main complication is charging these battery packs. Making a circuit to charge them is possible but they charge very slowly. In the U.S. The easiest option is something Made by Egen. They make the Cellink Neo/6 and the BlackVue B124. They are both identical so pick whichever deal is best for you.

I have the BlackVue DR750S and a BlackVue B-124. It used to only last under a day so I made a DIY extension battery and now it lasts over 60 hours. It charges at 7A.
If I were to build it again I'd go a complete DIY route. It would cost nearly the same but about week of capacity in under 1 hour of charge seems very possible.
 
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Steven Seagal

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I appreciate your comments. For the most part the USB packs are a backup to my vehicle battery. I plan on getting 20000 mah usb and just letting them sit there if needed. If it's using my vehicle battery most of the time, i don't expect to there to be much drain at all on the USB battery. i would just charge those at my house when I had a chance.
 

SawMaster

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G1W-S, G1W-HC, G1W clone, B1W, N2 Pro, K2S, B2W, (ex Mobius)
Lithium batteries such as are in powerbanks are not meant to go unused with a full charge for any great length of time. Their capacity will drop quickly if stored at more than 40%-50% of their capacity. I've heard of decent results with a 60% charge and good cells but never with over that. Storage at about half-capacity is still a lot of power and will make them last the longest. There's no great portable battery solution I know of for storage use, but some folks use an AGM jump-start battery device for this purpose and many of those do have USB ports as well as 12V outlets. That might be a better investment for you ;)

Phil
 

viperman_69

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I made a solution to your problem, check out my posts, because apparently its bad to link back to my post. its a UPS for 5v system. If you want to use a power bank, it has to be at least a 30w usb c pd input power bank, if you plan on charging it while you drive. I guess its bad to store lithium power banks in your car, but personally I have never had any issues. There are plenty of solutions to your problem. http://www.icstation.com/m350-backup-battery-switching-module-high-power-board-automatic-switching-battery-power-module-150w-p-13096.html
 

viperman_69

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my comment above is for everyone else Steven... cause I already showed you that of course.
 

Dashmellow

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I made a solution to your problem, check out my posts, because apparently its bad to link back to my post. its a UPS for 5v system. If you want to use a power bank, it has to be at least a 30w usb c pd input power bank, if you plan on charging it while you drive. I guess its bad to store lithium power banks in your car, but personally I have never had any issues. There are plenty of solutions to your problem. http://www.icstation.com/m350-backup-battery-switching-module-high-power-board-automatic-switching-battery-power-module-150w-p-13096.html
https://dashcamtalk.com/forum/threads/ups-for-dash-cam.40510/ :)

Can your solution be made to function with a 12V power bank?

https://www.amazon.com/gp/B00YP823NA
 
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Steven Seagal

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My car already has an AGM battery, so this is just to supplement that power. The good news is that the 5v -> 12v step up adapter from amazon does provide enough to power a 12v dashcam. I used a 10000 mah USB battery. I tested it on a Thinkware F750 and it worked fine. I'm going to test it with a dual camera Blackvue DR900s soon and report my findings.

Not concerned about charging the USB battery at this time.
 

jokiin

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Too many ¯\_(ツ)_/¯
I made a solution to your problem, check out my posts, because apparently its bad to link back to my post. its a UPS for 5v system.
linking back is totally fine when it's a part of the specific conversation
 
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Steven Seagal

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Blackvue DR900s works fine with a USB battery bank and the 5v -> 12v step up adapter. Both cameras connected and records just fine. My next step is to add a switch to change power sources when one fails.
 

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viperman_69

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As far as I know, that is just for switching power. I can not recommend anything. A youtube search should show something.
 
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Steven Seagal

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I finished my first revision. This will automatically switch to usb power once it detects that power is shut off from the car. I can leave my USB battery bank plugged in and it will automatically provide power without worrying about waking up from auto shutoff mode. The dr900 doesn't immediately shut down and keeps the power on so that recording is never interrupted.

I made this using automotive relays, a USB 5v to 12v step up converter and a 12v cig extension cable. I haven't run any extensive tests on it yet. So far, the relays get warm after driving around for 20 mins. As comparison, the blackvue camera with without the rear camera attached is warmer than the relays. The 5v to 12v step up converter isn't warm at all. Battery pack is an Anker 10000. Will play around with it some more.

Here's a video of it in action. Sorry for landscape mode. You can hear my click off the ignition in the beginning. The USB battery immediately switches on to provide power (4 LEDs light up). Blackvue camera never turns off.

As for charging the USB battery while driving, I thought I could just leave the battery plugged in to the car's cig adapter that switches on and off with the ignition but I noticed that the USB battery stays on for 15 seconds (depending on the brand) once there is no longer anything drawing power from it. I wouldn't want to risk trying to charge it while it was still in that state. I saw on the forum that there's a delay switch that could be used in this scenario but I'm happy with what I have and I'll be charging the USB battery manually.
 
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Steven Seagal

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Here is the whole thing. It's kind of big right now and I'm thinking of ways to reduce the size. The plan will be to power it with a hardwired power magic pro and once it shuts down based on the voltage reading, it will switch to USB battery pack.
 

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Steven Seagal

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There are 2 relays. The 12v from the car battery (power magic pro) triggers both relays. On the top relay, it redirects power to the dashcam from the car battery to the 5v -> 12v step up adapter when it doesn't detect 12v from the power magic pro.

Once the 12v power source from the car battery shuts off, the lower relay completes the circuit for the usb male cable to the 5v -> 12v step up. This tricks the USB battery into thinking that it was just plugged in and turns the USB battery on. Since the relay completes the circuit, the 5v to 12v step up is enabled and powers the dashcam plug at 12v.
 
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