Help with Renogy 50 dc-dc mppt!!

[Just_a_van]

I look to see if I found this question somewhere before I posted this, and I couldn't find it. So let me lay out my question / situation
I have three 100 watt panels going to a renogy 50 amp DC to DC charger/mppt controller. This goes to two 50 amp hour renogy lithium batteries. That are wired together for 12 volt. The mppt has the option for alternator input but I don't use it. my question is I recently purchased a renogy 20 amp battery charger for their lithium batteries. The kind that you just plug into a wall and alligator clip to the batteries. What I want to do is take the battery charger and hook it up to the alternator side of the mppt charge controller so that with my Bluetooth it will track how much I'm charging from shore power when I am.

 

[Just_a_van]

Haha nothing

 

[MisterSandals]

Powering a charger with a charger is never a good idea.

 

[MisterSandals]

the mppt charge controller so that with my Bluetooth it will track how much I'm charging from shore power when I am

I do not think the Renogy DCC50 has a shunt which would be necessary to accurately track charge/discharge (coulomb counting).
If the DCC50 estimates the SoC by voltage, you can connect the shore power charger to the battery and achieve what you are trying to do.
Just so you know voltage is not a good way to estimate SoC (but i am pretty sure we all do it to some extent).

 

[Reed Cole]

Powering a charger with a charger is never a good idea.

It would probably be fine if they connected the AC powered charger to the starter battery first, but it makes more sense to just get a shunt based battery monitor to achieve their actual goal of monitoring current in/out of the battery bank.

 

[Just_a_van]

I do not think the Renogy DCC50 has a shunt which would be necessary to accurately track charge/discharge (coulomb counting).
If the DCC50 estimates the SoC by voltage, you can connect the shore power charger to the battery and achieve what you are trying to do.
Just so you know voltage is not a good way to estimate SoC (but i am pretty sure we all do it to some extent).

It tracks the charged amp hours coming from solar, and it says it does the same thing coming from the alternator. so I didn't know if I could substitute the alternator for an actual charger. Thank you for the heads up I guess I'll just go with a shunt

 

[MisterSandals]

It tracks the charged amp hours coming from solar, and it says it does the same thing coming from the alternator.

Ok, thats a nice feature. I did not know the DCC50 had that.

 

[Kesa32]

You can always get their https://www.renogy.com/500a-battery-monitor/

 

[Just_a_van]

Ok, thats a nice feature. I did not know the DCC50 had that.

The unit stores the data but you need a Bluetooth module to access it via an (somewhat unstable) app

 

[Just_a_van]

You can always get their https://www.renogy.com/500a-battery-monitor/

I thought about that, I was just trying to see if there was a way I could utilize what I had without buying more equipment. I probably will end up getting it though. I'm 99% sure my battery fully charges in a day, but that 1% drives me crazy not knowing

 

[Reed Cole]

Hard to argue against a good battery monitor, at glance you can tell if everything is working properly or not.

 

[riker1]

Strange that Renogy dies not offer this via the RS485 Interface.

or did I muss anything?

But the BT -2 should support this.