I have an AiLi battery monitor. It works great with my DC system but when I wired up an inverter, the battery monitor does not register. It's weird because the both the positive and ground of the inverter both goes to the main battery. So in theory they should be both hooked up. Any ideas?
AiLi battery monitor wiring issues with inverter
- Thread starter alex01
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FilterGuy
Solar Engineering Consultant - EG4 and Consumers
A few things:
* Could you provide a diagram of your set-up?
* Check all the wiring. This is what you should find at the shunt
At the other end of the cable use a volt meter to see if everything looks correct.
Does the monitor light up but not work? if so I would look closely at the V sense lines. If not, I would look closely at the Power +/- lines.
* Could you provide a diagram of your set-up?
* Check all the wiring. This is what you should find at the shunt
At the other end of the cable use a volt meter to see if everything looks correct.
Does the monitor light up but not work? if so I would look closely at the V sense lines. If not, I would look closely at the Power +/- lines.
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FilterGuy
Solar Engineering Consultant - EG4 and Consumers
I just re-read your post and something caught my eye:
"both the positive and ground of the inverter both goes to the main battery. "
The shunt should be between the battery negative and *all* charge and load sources.
Edit: Updated image
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I'm a little confused with that diagram where it says to all load and charge sources on both sides.
Right now my P- only has one wire that goes to the chassis ground. Then B- is a common ground for all my appliances and battery. I thought that was ok from the instructions.
The meter works perfectly for everything except reading the draw from my inverter. But it's strange because there's nothing special. The inverter just connects to battery which is common ground to B-
Right now my P- only has one wire that goes to the chassis ground. Then B- is a common ground for all my appliances and battery. I thought that was ok from the instructions.
The meter works perfectly for everything except reading the draw from my inverter. But it's strange because there's nothing special. The inverter just connects to battery which is common ground to B-
Bob142
Build more, learn more.
Check out the info I posted in another thread about the Aili. Maybe it will help:
diysolarforum.com
AiLi Battery Monitor
After seeing Will's youtube feature on AiLi Battery monitor I ended up getting the 350A one and fitted it today to the caravan. It works very well but I have a question I'm hoping someone can answer. Due to a small current flow to the hard wired CO/gas alarm the backlight of the AiLi screen...
diysolarforum.com
FilterGuy
Solar Engineering Consultant - EG4 and Consumers
Please provide a diagram of your set-up.
Is the inverter negative on the B- or P- side of the shunt. If it is on the B- side of the shunt, the shunt can not measure current going to/from the inverter.
Yes, the P- will typically go to chassis and, in you case it sounds like that is also the negative return for all of your devices except your inverter. That means the shunt is measuring the current to/from all of the devices except the inverter.
As a side note: chassis ground is not typically considered a good path for the negative connections to appliances/devices. If I am understanding your set-up you are putting a heavy gauge wire between the inverter and the battery negative. That is good but it needs to be to the P- of the shunt, not B-
Edited to add comment about gauge
You may want to consider adding a negative return wire for all of your other devices as well. (They should be the same gauge as the positive wire to the device) You should at least consider doing it for any high current devices you might have on the circuit.
BTW: In my drawing above, I notice I show the fuse on the negative side. That works but I typically put the fuse/breaker on the positive side. (I started with a drawing I had from helping another guy that had the fuse on the negative.) Here is how I more typically would do it:
Notice that the tiny positive wire to the shunt is fused seperately. The main fuse would not even notice a short on the tiny wire going to the shunt. Without the device fuse the tiny wire could become a very smoky fire-prone fuse.
There have been complaints about not showing proper fusing in diagrams so I am trying (and typically failing) to remember to do that. Whenever you see a diagram from any of us, don't assume the fusing is correct. If you are not sure how something should be fused, ask.
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That's really helpful, thank you! I think that's my problem, my common negatives is connected to B-. I'll change that to P- tonight and see if that works. For return negative, would you connect that back from P- to the battery in addition to the chassis ground?
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FilterGuy
Solar Engineering Consultant - EG4 and Consumers
I am not sure what you are asking, but I *think* the answer is no. If I am understanding your set-up, this is what is should look like.
Note: If the main fuse on the battery is small enough to protect whatever gauge wire is going to the inverter, the additional fuse on the positive to the inverter *may* not be needed but it is still a good idea to have if the max current to/from the inverter is less than the main battery fuse. Also, if the inverter does not have some type of over-current protect built in, there should be another fuse or breaker on the positive close to the inverter.
A few guidelines for fusing:
* All current sources should have a some form of over-current protection in them or right next to them.
* The fuse should be rated at 125% of the max power expected on the smallest wire in the circuit the fuse is intended to protect.
* Anytime a smaller wire connects to a larger wire, it should probably be fused.
GVSolar
Solar Enthusiast
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Based on that formula, what would be the appropriate size/rating for the Aili monitor positive fuse? Thx.
FilterGuy
Solar Engineering Consultant - EG4 and Consumers
So.... by the guideline, you would use a .015A fuse.... That is a tiny fuse. When you get down to this small of a current, you can fudge it some. I would probably put in a .5 or .25 amp fuse and call it good. Here is my reasoning:
- Any wire I use to hook this up will handle an amp without burning. Even a 1 amp fuse would blow before the wire burns.
- Any short inside the meter is going to mean replacing the meter. (I am not trying to protect the meter) Furthermore, an internal short might smoke but it is very unlikely to cause a fire at .5 amps.
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rayfound
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P- should be treated as if it were your negative battery post. B- connects to battery, everything external to battery goes on P-.
Thank you!! That simple statement clarifies how to connect very nicely.
xjaywalker
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- May 13, 2020
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Sorry to highjack this post. I just installed the AiLi and double checked all my connections and at first I was able to rest the battery SOC to 100% (they were fully charged) then the display switched to 0.008 A, now it is stuck there. Holding the button for 3 seconds does not work. I disconnected the unit and waiting a minute or so and plugged it back in and it is still stuck at 0.008 A. Any Ideas????
Bob142
Build more, learn more.
Press the button on the left. Does the display show you voltage? Pressing the right button should show your battery capacity in %. If you press the middle button it should toggle between amps and amp hours.
xjaywalker
New Member
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None of the buttons will change from the 0.008 A display. It is stuck
solarstuff
New Member
Could you answer a quick AiLi install Q?
Am I ok installing the inverter to the AiLi battery monitor BUT leaving my 2 MPPT's attached to the inverter?
Or, do I need to attach each of the MPPT's to the AiLi battery monitor as well as the inverter?
I don't have a fuse box or bus bar in themix.
Thanks folks!
Am I ok installing the inverter to the AiLi battery monitor BUT leaving my 2 MPPT's attached to the inverter?
Or, do I need to attach each of the MPPT's to the AiLi battery monitor as well as the inverter?
I don't have a fuse box or bus bar in themix.
Thanks folks!
FilterGuy
Solar Engineering Consultant - EG4 and Consumers
I am not following your description of the set up. Could you provide some kind of diagram?
Bob142
Build more, learn more.
I went back and looked at your pic from the toaster oven thread to double check. Since your inverter negative wire(s) are the only ones directly connected to the battery bank you will be fine connecting the shunt between them and the battery bank main negative terminal. By doing that you've effectively connected the MPPT negatives to the AiLi monitor (via the inverter terminal then the inverter negative wires).
solarstuff
New Member
Thank you Bob, Filterguy! And, is a fuse overkill? I'd be using 12 AWG wire.
Bob142
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Where?
solarstuff
New Member
Oh-sorry...the teeny red wire that powers the monitor and connects to the battery positive.
Bob142
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Max 18 AWG for that wire. And yes, fuse it.
solarstuff
New Member
Bob142
Build more, learn more.
Whatever small fuse you have handy. I believe I used 1A on mine since I had some.
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