Insides of BlackVue B-124 (DIY 11,852 mAh @12.8v / 151.7 W/h + extension battery for under $50?)

[Tomcat]

Due to the corona crisis i didnt order any parts from aliexpress as those would be delayed. Some time ago i did order a 15a 220v to sigarette charger that can supply the 9a hardwire mode but its still stuck at customs in my country so have to wait it out and use the 5a i already have. Also here there is a 22 euro tax free limit. Above that you get some hefty customs/tax fees that makes the prebuild aliexpress batteries almost as expansive as the 165 euro i payd for the nrg that shipped in 2 days. Otherwise i might have bought a turmera or kanavano battery. Those seem to offer really nice capacity at very affordable prices. in the end i went with the 20ah lifepo4 from nrg it is comparable to those from all-batteries.com but also ships here from the netherlands. It has a bms that monitors temperatures which is a wise addition.
I had to make the xt60 extension cable with parts available in dutch webshops. I used proper cable connectors those that you grip onto them to connect everything together but had to use the isolationtape to tie over it as car store that sells the nice shrinking hoses is closed until atleast 28th of april.
After I assembled the cable i tested it it works flawlessly the battery also charges really nicely in both 5a sigarette and 9a hardwire mode. It stops charging when the bms values that are the same as the b124 are reached.




It should give me a 24/7 parking mode for around 5 days.

 

[joe384]

256Wh is great! So you just have it connected to the B124 as an extension?

 

[Tomcat]

Yes im running it b124+b124e+256wh battery. But it also works and charges fine when connected directly to the b124 alone i already tested that.

 

[Progen]

I've been lurking on this subject for the longest... so let me get this straight. In layman's terms to add capacity to the existing cellink setup the easiest way possible:

1. purchase a LiFePO4 battery that is pre-assembled (with a case)
2. solder/clamp a male xt60 connector to that battery
3. connect the male xt60 connector to the Celllink neo or whatever other cellink you have set up
4. set the new capacity to the cellink neo app (by adding the two battery capacities together?)
5. ???
6. Profit?// hope the expansion doesnt light your car on fire?

does the LiFePO4 battery have to have a BMS at this point since youre connecing to the cellink? would it use the existing bms from the cellink unit?
Thank you in advance for any responses and please excuse my ignorance.

 

[torribianche]

To be safe, I'm using one lifepo4 batt that has bms too.



Sent from my VOG-L29 using Tapatalk

 

[Tomcat]

Every expansion batterypack has to have its own bms as to balance the cells when charging and discharging. I recommend one which also monitors the temperature. Even tough your dashcam only draws little current. When charging with 9a in the heat of the summer even tough its split between 2 or more packs you dont want it to become to hot.
Most prebuild packs from all-batteries.com do have a temperature measuring bms. Some even have there own bluetooth apps.

i think you can run more expansion batterypacks in parallel as long as the output voltage stays the same but not in serial as that would double the voltage. I haven’t tested more parallels yet. But the blackvue b124/cellink neo basically dous the same you daisy chain battery packs in parallel for more total capacity.

the 256wh lifepo4 battery i used is enough for me i now only need to charge/drive it once or twice a week. And i can fully use the blackvue downloader app to download parking files to my computer.

I use a 15a charger from aliexpress that can supply the full 9a hardwire charge speed without issues .Everything is fully charged from 0% to 100% in aprox 3.45 hours.

 

[torribianche]

@Tomcat where do you connect your charger to? Home electrical plug?

 

[Tomcat]

Yes i use a extensioncord that i run to the house walloutlet. I only need to charge it once a week. I got both the 180w charger and the 15a sigarette to xt60 cord from aliexpress.

 

[torribianche]

Does anyone know what happens if the extension pack has more juice compared to the main cellink pack? Like for example.. i) Cellink pack is at 10%, extension pack is recently charged to 100%? Will the two pack rebalance? Or just draw from the extension?
ii) Cellink pack is at 0%, while the extension pack at 100%?

 

[Nigel]

Assuming the cells are simply connected in parallel, they will balance out next time they are charged to full. In case ii) the full pack may charge the empty pack for a while and they will partially level out. Ideally they should be connected when at roughly equal charge since power could flow quite fast between them, but in reality it won't due to voltage drops in the cells and cables.