BlackVue DR400G-HD Lens Cleaning and Battery Replacement

After an infamous thread on RedFlagDeals regarding an insurance fraud scam foiled by a person’s dashcam, many people started installing them as their own insurance, or simply to point out and ridicule poor drivers.  Sometimes people catch some crazy events.  I ended up purchasing a BlackVue DRG400G-HD from a group buy.  It was one of the better cameras at the time, 1080P recording, GPS, and a nice sleek build.  There are more affordable ones out there now such as the G1W which I have installed for my family members.

Most recently I captured lightning striking a utility post and it took out power to a traffic intersection.  When I went to check the footage, I found that the image quality was very poor.  I knew it was getting worse but always attributed it to a degrading sensor due to summer heat.

My camera also had an issue shutting down — it would no longer say “BlackVue now shutting down” when the power was cut.

Instead of tossing it for a new one, I opened it up for a little bit of maintenance to get it running like new.






AFTER CLEANING:drg400-after

Disassembling the BlackVue is very straight forward.  There are four screws consealed by four rubber stoppers.  Pull them out with a small flat screwdriver or tweezers, then unscrew the four screws with a small Philips screwdriver.


Once you get the screws out, split the shell in half.  One side will come off freely (the one held on by screws).


The other half is attached to the button on the side.  You will need to lift the board out of the little plastic tabs gripping it.  Pull it “down” and out on the shell away from the side you are gripping.


Here is a front on view of the dash cam minus most of the casing.  The yellow plastic contains the small rechargeable battery.  Underneath it is a small button battery.



Once you free the PCB from the other half of the shell, there are two screws attaching the lens to the PCB.  Unscrew those and wiggle the lens free.  One side will lift up and out first.




Here you can see the film that built up on the inside surface of the lens.  Clean it.  I chose to use LCD screen cleaner and a cotton swab.


Very clear now, minus some dust specks inside the lens itself.  Not much you can do about this.


My unit also had issues with not shutting down cleanly.  It would no longer say “BlackVue now shutting down” when power was cut, resulting in a corrupted last minute of recording. I ordered a 3.7V 150mAH battery off eBay with the approximate dimensions of 17mm x 14mm x 6mm.  I could have gone with slightly larger but I couldn’t find any matching the correct specs.

Remove the white connector and peel the battery off.  It is fixed using a small adhesive pad.


Here is a comparison of the stock battery and my replacement battery.



I didn’t have spare terminals so I opted to splice the new battery onto the old battery connector.  Be careful when you do this, as you do not want to short the terminals and kill the battery.  Solder the tail onto the battery and heat shrink or wrap the wires in electrical tape.


Here is the replacement battery in place.


You can see it’s a bit too skinny.


Reassemble the casing in reverse, power it up, and give it a whirl!  My battery replacement and lens cleaning were both a success.  My dash cam shuts down properly with no corrupt files, and the recorded image is very clear and vivid.  Hopefully this gives your cam a breathe of fresh air.  Ideally you should take a look at your footage at least once a month to make sure it’s still capturing a clean image and clean as necessary.



Filed under electronics, repair

12 Responses to BlackVue DR400G-HD Lens Cleaning and Battery Replacement

  1. Pingback: BEWARE: when buying used/preowned dashcams - REVscene Automotive Forum

  2. Steven

    Can you provide details regarding the new battery? Where you got it, any model number etc.

  3. bz

    Hi Steven,

    If you search “150mah 3.7v lipo” on eBay you will get a number of results. Most sellers will include approximate dimensions.

    It was most economical for me to purchase a lot of 10, some spares for myself, family members, and colleagues.


  4. John

    Hi Brian
    Thank you very much for sharing this. I found out today that my DR400G had not been working since August. You blog helped me to make the diagnosis that it’s also a battery issue. My unit wouldn’t turn on (no lights) and I originally suspected if it’s a power supply problem or main board failure, then prompted by your blog, I disconnected the battery and hook it up to the power supply again, and guess what it fires up all fine again. So now I’m off to find a replacement battery.
    Btw, I live in Vaughan/GTA area, do you by any chance live nearby and I can buy one of the spare batteries you have? 🙂
    Best regards, John

  5. Kayax

    You SAVED my unit – THANK YOU!

  6. MIchael Wilson

    Yep, awesome post. I just re-fitted a new battery in my unit as per this guide and it’s working like a charm! FYI, I got the battery from here:

    It was longer than the stock standard battery, but thinner. Pretty much took up the vertical width of the board, so I had to use side-cutters to make a couple of small snips to little plastic wedges that press against the board in the external housing. Didn’t matter at all though, it fit snuggly and tight once I closed everything up again.

    I can’t fathom why Blackvue does not provide a faulty battery alert on these units once these things die. When you think about it, in either a major accident whereby the power will auto-cut out, or a minor accident where I’d argue most peoples instinct is to turn off the ignition immediately post collision, it would be heartbreaking to find out you lost the recording due to the battery being dead all along, and the buffer of the last 30+ secs of the recording is deleted. I seriously hope they have fixed this in later models.

  7. Marc

    Thanks for the information…I was having “check your SD card” issues and decided I would upgrade the firmware and noted that the date stamp was not functioning properly…Once I read this post I also remembered that the power down message was also not happening. Agreed that this is a major flaw in this product. Hard to explain in court why the date stamp was from 3 years ago…ahhh will a few dollar lipo battery might cost a lot more in increased insurance premiums

  8. pdes

    I even mailed Blackvue when my time and dates went haywire and they just sent me a file to manually correct the time! No mention of a battery problem. So, Just splicing the connectors now! Thanks

  9. Stan

    Very useful info, thanks a lot!
    I’ve found a video where a Russian guy replaced the battery with two supercapacitors (10F, 2.7V each):
    He says that in the heat those batteries die very fast and he got tired of replacing them. So he came up with this solution (which I think I will also try). One thing to note though, he does say that since capacitors come discharged from the conveyor belt, he had to INITIALLY cycle power after the capacitors wouldn’t charge past 2.2V.
    It takes approximately 45 seconds to re-charge the capacitors fully, which is pretty much the same time that it takes for BlackVue to start recording, so it all works out. 🙂

  10. Dannyaquak

    Имеется такая услуга – добровольное медицинское обслуживание .
    Она предполагает, что вы платите небольшую сумму за то, что посещает врачей в течение года БЕСПЛАТНО.
    Однако соцопросы показали, что лишь 4% жителей Питера знают о ее существовании.
    Да потому что частным клиникам намного выгодней сдирать с людей деньги за каждое посещение.
    А если честный врач посоветует добровольное медицинское обслуживание клиенту – это сулит ему увольнением.
    Эта информация уже вызвала много скандалов, после того как информацию об услуге рассекретил один возмущенный врач.
    Его уволили “по собственному желанию”, после того, как он посоветовал ДМО постоянному клиенту.
    Страшно, что официальные положения по ДМО находились в открытом доступе, просто находили на эту информацию только случайные люди.
    Как отстоять свои права?
    О правилах оказания услуги и обязанностях клиник можно узнать, просто вбив в Яндекс фразу: “добровольное медицинское обслуживание”.
    Обязательно обслуживание, а не страхование.


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  12. Andrew

    Hi there, I was wondering if I could get the connector for the battery somewhere? anyone know a part number? I tried to splice the wires and I need it to be a bit longer. Thanks

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