I've been looking for a deal on this for a few days and just noticed that this listing works with the 15% off eBay coupon.
If you have a battery system to monitor, this is supposed to be a great solution based on what I've read online. Pair it with a raspberry pi and VE.Direct to USB cable and you should be able to get live battery readings in Home Assistant.
Good price. Do they make them lower capacity as most people don’t need 500 Amp. Might be cheaper if they do. A battery monitor is a far superior way to keep track of battery use than just voltage.
500 Amp is the smallest, most shunts of that type are around that rating, though Victron do 1000A and 2000A as well (I use the 1000A myself). That's a very good price, and a well known seller as well - they do a LOT of victron stuff and also have physical stores.
There are plenty that are 100 Amp, 200 Amp etc, but there's no harm using a higher capacity one. It's just any brand that makes them in various capacities the lower ones are cheaper.
Dont be a smart shunt!
Mate, there's dumb shunts everywhere
I use these every day at work, awesome product, great price.
What sort of batteries do you guys use?
Eneloops of course
I use this in my 4wd in a 12v lithium setup and can confirm it's a decent piece of kit compared to others on the market. I have it paired with its companion LCD screen in the cabin for times when only a quick glance is sufficient and I use the bluetooth app for when I need a detailed analysis of my 12v equipment.
I don’t believe you can attach a screen to this model. You must have a BMV-712.
I much prefer one that has a gauge rather than have to look at my phone. Bluetooth is ok if you want charts, graphs and a history, or have a system where everything is connected to one smart panel that controls it all. I prefer having device with display. Though if I were planning a setup from scratch I might then go for the centrally controlled type.
Correct, I have the BVM-712.
Imo they should make the app for Android Auto and Apple Car. So much easier to have a quick check. Same with the 12v fridge apps.
I just bought one at same price and fitted to my camper trailer. Works pretty well but Bluetooth signal can be average depending on where it is fitted.
Yep, the BMV-712 has a far better Bluetooth range.
Can someone kindly explain what a shunt is and does? And in which circumstances it’s useful or even necessary vs just nice to have?
I’m looking into a Lithium battery setup for camping, battery will be external, not installed in car. Wouldn’t my MPPT inverter show me battery state?
It will show how much charge your battery has. It's placed in the circuit & will see input & output charge to give you an accurate reading.
Different battery types are best only discharged to a certain level for the best balance of cost/life/capacity. For lead acid (LA) that's 50%. Generally for lithium it's down to 20%. So a 100Ah battery will only have 50Ah (LA) or 80Ah (lithium) usable capacity. Better battery selling sites will quote a number of cycles at a certain discharge level. For example 200 cycles at 50% for LA. 2000 at 80% for Lithium. There are other types in between like AGM or Gel. You can discharge lower, but that will shorten the life of the battery.
The crude way to assess how much of your battery you've used is voltage. LA, for example is 12.2 volts (50%). A battery monitor is a gauge (or in this case it's bluetooth to a phone) connected to a shunt (on the battery). This much more accurately measures what's coming in and going out of the battery and gives an Ah or percentage figure. Also tells you how much power is going in or out that instant so you tell how much power a device is using. They're not essential, but very useful, particularly if your battery capacity is borderline and you're in danger of exceeding the sensible depth of discharge.
Thank you, very helpful.
Will a Lithium battery give any voltage indication of being about to be discharged too much or is this only possible/more accurate using a shunt?
Here's a rough example for a lfp: at 13.3v the state of charge is approx 90%. Turn on an 1200W airfryer the voltage drops to 12.4v (at rest, this would indicate <20% charge). When the airfryer is done, the battery returns to 13.17v after a few minutes (approx 60%). So you can tell using voltage, but you'll need to infer what's happening when it's under load.
Here's the first thing I found on Google showing this. If you look at the chart called 'What is LiFePO4 Voltage Chart' at the 12 volt column it shows 20% is 12.8 volts (which highlights another benefit of lithium - the voltages are just a little higher so your water pump runs better). 12 volts is 5%. I wouldn't go any lower than 12.5%.
What tends to happen is when you're using something the voltage goes down (of course), but if you turn that device off, the voltage will bounce back up a bit. So in practice you can go a little bit lower than the limit you decide on.
You can get really cheap battery monitors on ebay etc. Either generic or brand name ones. I got a Renology one which is ok, but in retrospect I should have got a better one. My preferred brand is Votronic, but they're more expensive. They have nice looking displays and compact, well spec'd equipment. They just don't do the all singing bluetooth stuff Victron does (which I don't want).
https://www.jackery.com/blogs/knowledge/ultimate-guide-to-li….
@wfdTamar: Thanks again, and watched some videos. Still, how does a shunt ‘know’ what battery capacity it need to reference to estimate all else? I get that I can set it to the battery capacity max but how does it ‘know’ what the battery capacity is at any given time, simply monitoring Amps drawn and guesstimating?
@MerlinKlendatu: That's my understanding and you tell the shunt what size the battery is and it just monitors the amps in and out to determine the SOC.
@MerlinKlendatu: You tell it on the display or in the app (as for this Victron one). You make sure the battery is fully charged then you press a setting that tells it (for example) ‘this is the 140Ah battery fully charged’.
Thanks, purchased.
Good beginner video, installation, app, demo, etc: https://www.youtube.com/watch?v=_GjcGZsK4fI
Shows how good the Victron app is. If you're happy to look on your phone/tablet and found that info useful (over what you you might get on a display) that alone is worth paying more for.
Here's an example of a cheap one ($70) that is ok. The Renogy one looks the same.
Yeah that one should be sufficient if you don't need the connectivity and just want basic monitoring
The reason I went for the Victron one was its ability to connect to home assistant (via Venus OS and the VE.Direct cable)
Essentially with my set up the readings off the shunt will automatically engage or disengage charger/load circuits and trigger various automation via home assistant
I use Renogy unit on my van. Providing me with suitable information, eady to use.
yeah this one is an unbranded renogy one, ive got one and it works well if you dont want an app
Went victron for my off grid system and never look back, good stuff. Might grab another shunt as it can be set as a dc meter. Worth every dollar
Tempting but the LiFeP04 battery I just bought has a bluetooth BMS that shows SOC, amps, volts etc so the only benefit I can see is you can see historic info with the shunt app but not with the BMS app I have.
This is awesome but be warned that the Bluetooth sucks.
If your shunt and charge controller are not together, or separated by steel or other metals, the ve networking may not work.
Also, getting a reading can be hard unless you are very close to it.
I bought one and put it in our camper trailer and it gave us all the above mentioned issues. I regret not getting the bmv which sounds like it has better Bluetooth.
You can't add the bmv remote module to a smart shunt.
If none of these things matter to you then go nuts, it's great .
"Pair it with a raspberry pi and VE.Direct to USB cable and you should be able to get live battery readings in Home Assistant."
Can confirm this works flawlessly.
I have a small router with sim card connected to the Pi running Venus. All data from battery monitor and solar charger displayed in Hone Assistant via MQQT. Works great