AiLI battery monitor on solar does not show it's charging

[free01]

Hi all!
I have had the AiLi battery monitor installed on my RV now for going on 3 years and it's been amazing. Up to this point I have used it only with shore power, when we dry camp and use a generator everything works perfectly, the Volts, Amps, Ah and % has been dead on (based on my volt meter testing). I have two Trojan 6v T-105s wired in Series which has performed fantastic. Now I have entered into the Solar arena, and I have a 100w DOKIO 18v portable hard sided solution I wanted to try out, hoping to reduce generator usage when dry camping, and specifically when we leave our site. When I connect the alligator clips to my +positive/-negative going TO/FROM the RV I do see my 'volts increasing' on my AiLi inside the RV however my symbol still shows the down - arrow, which means it has a negative draw. Additionally, on the AiLi my % is still decreasing as well as my Ah which when I charge from shore power I always see a + up arrow indicating I've got a charge going back into the batteries, my percentage always increases along with my volts and Ah etc. Last data point, on my solar PWM charge controller it shows roughly 1.4-2 Amps going back into the RV. I do realize at this point in time that is not a lot, but on the RV my parasitic draw is only .126 which is much less Amp than should be going back into the RV.

Anyone else use a portable Solar kit and connect directly to your batteries like this? Any thoughts on how to fix this, or other suggestions from you experienced folk?

 

[sunshine_eggo]

Because you have bypassed the shunt. You attached the charger to the battery. The shunt can't "see" any of the current going into the battery.

Negative charge lead should go on the side of the shunt opposite the batteries.

 

[free01]

Because you have bypassed the shunt. You attached the charger to the battery. The shunt can't "see" any of the current going into the battery.

Negative charge lead should go on the side of the shunt opposite the batteries.

Hmm... so you are saying, I should take my negative and attach to the negative on the actual shunt? I had not considered that, and... since my shunt is attached to my A-Frame of the travel trailer I sealed it up inside a weatherproof box, so that would kind of stink. I would need to come up with a quick attach for the shunt negative then. With this in mind, is it a good idea to connect two quick disconnect SAEs, one to my positive and one to negative on shunt and then use a SAE from charge controller directly to my new SAE quick disconnects?

 

[mikefitz]

Connect the negative from the panel to where all your other negatives connect , there must be a common point some where that's accessible.

Clips or lose connections on battery terminals can create sparks, T105s gas significantly, you have a good chance of exploding batteries.

 

[free01]

Connect the negative from the panel to where all your other negatives connect , there must be a common point some where that's accessible.

Clips or lose connections on battery terminals can create sparks, T105s gas significantly, you have a good chance of exploding batteries.

Hmm... so you are saying, I should take my negative and attach to the negative on the actual shunt? I had not considered that, and... since my shunt is attached to my A-Frame of the travel trailer I sealed it up inside a weatherproof box, so that would kind of stink. I would need to come up with a quick attach for the shunt negative then. With this in mind, is it a good idea to connect two quick disconnect SAEs, one to my positive and one to negative on shunt and then use a SAE from charge controller directly to my new SAE quick disconnects?

Because you have bypassed the shunt. You attached the charger to the battery. The shunt can't "see" any of the current going into the battery.

Negative charge lead should go on the side of the shunt opposite the batteries.

I think I may have found a diagram that shows what you are talking about... This look about right?

 

[free01]

Ok - posting a follow up in case someone else comes across this thread and wants the power to run back through to your battery monitor. Shout out to sunshine_eggo for diagnosing my problem! In my setup, I have two 6v Trojan T-105s wired in series, and a AiLi Battery monitor wired using a shunt as designed. My portable solar charges my batteries, positive to the positive battery terminal and negative connects after the battery onto my negative/ground shunt connection. I realize my amps going back in is low right now but it is cloudy. I will also wire a quick disconnect to my shunt and battery, but at least I have validated everything works as expected now. The problem I was trying to solve is that my AiLi was not reading any charge going back into the batteries. With this change, now it does as seen in the AiLi with the + up arrow. Again, thank you to this group!

 

[sunshine_eggo]

The (-) charge lead can be attached at any convenient point that ensures it passes through the shunt. if your frame is grounded to that side of the shunt, then you could attach to any suitable point on the frame.