Battery Status heads up display

[Diesel Pro]

Current plan is 8S 24v 280AH using a JK smart BMS with bluetooth. I'm also considering a secondary heads up display display. Something that a friend or family member can look at and tell me what the status is if they do a check in. I'm wondering if I should do the whole shunt/meter thing or if I would be best served trying to run something off the JK BMS. Seems simpler to use the JK BMS but this is getting beyond me as to what to use.

Something like this. And of course which version, CAN, RS, adapter?

10.0US $ 1% OFF|Jikong BMS RS485 CAN module and LCD display Adapter|Battery Accessories & Charger Accessories| - AliExpress

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[MisterSandals]

Something that a friend or family member can look at and tell me what the status is if they do a check in.

To make it "more" idiot proof, I would want to know something simple like battery voltage. This is a pretty foolproof measurement and will tell whether your system is fine or not.

Even if you were told the SoC, since they can drift, you'd want to know the voltage anyway.

 

[Diesel Pro]

Am I on the right track here thinking that the BMS data should be simple and as accurate as anything once properly calibrated? No need to add a shunt/coulometer?

I'm assuming that the JK BMS monitor I need a display and either a CAN module or RS485 module and should be good to go?

 

[brucemunro]

I'm in the same boat (building a 16S 48V EVE 280K system for our Motorhome that arrives in June). I just ordered the
JK-B2A24S20P-CAN as I'd like the future flexibility for CAN-Bus. HANKZOR store (on Aliexpress Chat) confirmed that the RS485 module will work also so I have both options open. On the display, I ordered their simple display and was looking for more information on what is shown but can't find much. I like that it has the BMS On/Off switch but would like more on the display modes. It seems to offer SOC, Voltage and Current displays, hopefully with a discharge or charge indicator. Time Remaining and Charge delivered/time to go etc may all be either on the App or provided by a seperate Coulombmeter or Shunt.

From: https://www.aliexpress.com/item/100...o.store_pc_groupList.8148356.4.55d17062lyXAgL

I plan to have plenty of time to run it up and test in March in time to allow ordering (if needed a seperate system). I really like the look of the Junctek KG140F ahead of the more basic Shunt style displays as it provides the App and a longer RJ11 style cable for the display to be seperate to the sensor and "brains" box. Not really budgeting for the Simarine or Victron display solutions, though that could be a future upgrade....

56.0US $ 50% OFF|Kg140f High-precision Coulomb Counter Lithium Battery Battery Car Battery Indicator Lithium Iron Phosphate Capacity Detector - Battery Testers - AliExpress

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Not advertising, just sharing my research, hope this helps

 

[Mike Jordan]

Raspberry Pi running Venus OS, with a Victron Smart shunt, displayed on a hacked laptop monitor. I got $50 into a $600 retail set up
(smart phone too, screen shot pictured) You can see it anywhere in the world if you have an internet connection. No family member interpretation needed

 

[brucemunro]

Raspberry Pi running Venus OS, with a Victron Smart shunt, displayed on a hacked laptop monitor. I got $50 into a $600 retail set up
(smart phone too, screen shot pictured) You can see it anywhere in the world if you have an internet connection. No family member interpretation needed

Thanks Mike, will research more into this.

 

[RossA]

I'm curious if your JK BMS current readings are accurate. I don't really have any way to measure what the batteries output is except for my JK BMS. What I'm concerned about is that my batteries voltage has been dropping WAY faster than I would have expected from these cells. I bought 8 304 AH EVE cells from Docan Power. The cells visually look really good. I hooked them up with balance leads to the BMS and then to an inverter. Slowly charging them with my 24v inverter connected to a wall outlet allowed my BMS to slowly balance all of the cells, even at a high state of charge. So I've been running my LV2424 Hybrid inverter off of the cells for a little while now, just to measure capacity and make sure things were working properly.

I've watched the voltage a few times a day. My JK BMS claims that the inverter is using roughly 18w continually and that I've used about 80 AH since I fully charged the batteries up to 3.55v per cell. What is shocking to me is the fact that I'm now down to 26.08v. Based off of AH I should still have 224 AH and be at 73% SOC. Based off of voltage I'm at like 35% SOC. Thats a BIG difference. I'm wondering if the inverter draw is actually much larger than the 18w and my batteries are just getting drained a lot faster than what my JK BMS is seeing.

Any ideas?