Renogy 500A monitor not registering alternator charge

Hi All,

Firstly this is my first post, but I decided to skip the newbie corner and jump straight into the ddep end:

So I have a Renogy system; 2x100aH batteries, 50A DC-DC charger, 2000w Inverter charger & 300W solar in my van.

The issue with my 500A Battery Monitor is that it registers current & therefore charge percentage for loads, solar charging and AC hookup charging, but not charge from the starter battery.

I am sure current is going in as a) the app tells me it is b) after a 2hr drive the voltage had jumped from 13.2v to 14.1v when i stopped.
I’m at a loss because I believe it is wired correclty:
Any thoughts would be greatly appreciated!

@Monarch_of_the_Glen I had this problem after wiring my battery monitor into my system…it turned out that I had not connected the negative wire from the DC-DC charger to the “Load” connection on my shunt.

I hope this helps.

Hi Wey,
Thanks for the response.
What do you mean by the load connection? Is this not the P- connection that is running from my busbar and then in turn onto the DC charger?

I had what I thought was a breakthrough yesterday, in realising the battery was grounded on the other side of the shunt, which could’ve been stopping the reading, but I just dug out where the ground connection was made… and the geniuses have screwed the ground wires into a painted hole… one step forward, two steps back.!

I’m not sure if they’re all marked in the same way, but my shunt resistor is marked with “Battery -” which connects with one heavy duty wire, to the battery, and “Load -” to which all of the negative services and/or busbar (including the negative charging wire from the DC-DC charger) is connected to.

I made the mistake of connecting the DC-DC negative wire to the battery side of the shunt instead of the load side, which meant the shunt couldn’t measure the amount of charge current into the battery!

Hey @Monarch_of_the_Glen . Did you figure this out? sorry to bump an old post but i’m having exactly the same issue ! Any help would be greatly appreciated, its been driving me mad haha . Thank you !

I did get it sorted but it was a while ago and I fixed a few issues as described all in one go so it was hard to place one specific culprit.

First running a negative from the starter to the charger was definitely important despite what the installer told me (ie grounding was fine).

Secondly they had earthed the batteries to the chassis on the battery side of the shunt which is why I think it was charging but not registering on the shunt.

Is this the same for you?
Ultimately I unhooked everything’s and reconnected one by one. And used my multimeter to check the currents through each section.

They’d also told me it wasn’t a smart alternator when it is so that was another of my problem.

Shout out to Fastlane autocare in St Helens for making the first 6 months of van life entertaining!