$100 Caravan Battery Monitor Install and Review

I bought a cheap battery monitor off aliexpress and found it easy to install and worked well... So I thought I would share the details in case anyone out there might find it useful to see how I wired it into my twin battery system.
The unit that I purchased was junctek brand which is available in aliexpress here: a.aliexpress.com/_mtkv7qw
It's very cheap staring at NZD37 up to NZD100 for 400A i using a display unit (which is the model I installed).
Overall the unit seems to work well, comes with all required parts to install, and the mobile app provides effective monitoring of thr batteries.
Hopefully some of you will find this helpful 😁
#junctek #batterymonitor #batterymanagement #shunt #vanlife #savemoney

[@brianrozgodfrey2830]

Awesome review. Thanks

[@caravanwise]

Hopefully you find this useful if you're considering a battery monitor to get more accurate information on the state and performance of your battery system. Let me know your feedback. Aliexpress product link in the description

[@Marcel_Brouwer]

You followed the instructions from the manual, the only thing is that Juntec did not subscribed a fuse (5 or 7A) in the 12V feeding line into the control box. I would advise to install a additional fuse.

[@caravanwise]

You could be right. The draw on that 12v wire is minute do you think it is a material risk? Perhaps just a 1A glass fuse would be OK?

[@Marcel_Brouwer]

Just a small 1 to 5 A fuse will do@@caravanwise

[@RND-USA]

Hello! Thank you for creating this video! I have a question regarding its usage. Can this be used with cars or car starter batteries? If yes, do I need a larger shunt due to the spike in current caused by the car starting? I want to monitor parasitic drain current, which is under 1A I also have an mppt solar trickle system attached to the battery. However, I'm unsure if I need a larger shunt as my car battery has 500-600 cold crank amps (Honda Element 4.2L, 4 cylinder). I've seen many people using this product in RVs, but I'm not sure if they're using it on their starter battery or on their secondary/leisure battery only. I would appreciate any thoughts you may have on this. Unfortunately, I'm unable to reach the manufacturer or find a buyer’s guide.

[@caravanwise]

Pretry sure that you need the shunt to be rated to the same as your peak draw else it may not measure accurately? Unless the shunt size is a safety precaution? Perhaps more general advice (non juntek specific) might answer this qn for you?

[@RND-USA]

@@caravanwise In general my reading points to wanting to get a model that is closest to the low currents I’m wanting to track. However I’m still not sure if the smaller shunt unit will handle the starting crank amps. I heard back from an Italian camper KZbin that his Junctek can be used on any battery. I’m just waiting to hear back what the smallest shunt size is that can work with cars just to be safe.

[@jethrotull5847]

This meter seems well constructed but has issues. My major annoyance is the application demands “File and Media”, “location” and “nearby devices” Rights.. thereby exporting my data to some Chinese server. I use my meter on my Samsung S6 Tablet docked in the DEX ( desktop extension mode ) displayed on a big tv with all my other important data. I literally had to run a long HDMI cable to the basement and relocate the tablet downstairs just to keep a clean Bluetooth connection, even so.. I still have to search many times for the device if I restart the application ! I’ve tried the app on various phones of android and apple ! The “firmware update” freezes the application, furthermore the “CURVE” page doesn’t dependably work. This device could have been so much better… I bought my meter 6 months ago.

[@caravanwise]

Geez that's a rough ride. I've got 2 android devices using it and no issues at all. You're right about allowing location (set only while in use) this seems to aid connection. Storage permission - you can deny this and app still works. I find if you force close the app when you're done, to open turn on Bluetooth then launch and it works 💯 so not sure why you're having issues. I guess this unit tho is a hobbyist quality sounds like your setup is pretty elaborate maybe your quality expectations are higher than mine for $50? cheers for the comment hope that setting change helps u

[@jethrotull5847]

@@caravanwise it is possible I got a lemon. I’m going to Amazon another and return it if it gives me any misery. Thanks for the file rights thing and for this forum of comments…

[@caravanwise]

@@jethrotull5847 good luck

[@jethrotull5847]

@@caravanwise thanks, listen if you own a late gen Samsung device get a cradle capable of charging, giving usb3 ports and outputting video. DEX mode allows multiple windows open so as you drive you can view google maps, battery conditions, weather radar, and even blood glucose level.. like a cool mobile dashboard! Take care…

[@caravanwise]

I was thinking about what you raised earlier about connectivity issues and did some more testing myself. For the BM in my caravan I can connect from the tow vehicle when stationary but it loses connection once driving along. I tested on my friends caravan with their high end lithium battery monitor and same there - I don't think connectivity is intended for outside a close range and while stationary perhaps

[@NeoVdV]

Hello, I just got this device (the 2023 model) Is there someone who can make a video or send me info on how to install a relay to protect my solar system with Lipo4 batt. What kind of relay (12V array, with 300Ah 12V Lithium battery bank), and how to connect. Thanks in advance.

[@caravanwise]

What are you trying to protect the system from ie overcharge or over discharge? Not sure why you need a relay I didn't need one in my installation this monitor channels the load through the shunt so has nothing to do with charge side. Also, wondering does the device support lithium battery OK once you've set up?

[@NeoVdV]

@Caravan Wise , First, yes I use a 300Ah Lithium. Second, how can it do so via a shunt as there is no switch or limiter inside. Third, all protections.

[@april7_]

Got same type setup 200Ah LiFePo4 only one 200A Fuse in battery and connected as regular battery to my caravan. Worked 2 years now. You do not need any other "protection" in my mind.