I’m looking for a way to use excess power from my solar array to charge a secondary lithium battery once my main AGM bank reaches Absorption voltage.
With my main AGM bank, I’m wasting solar power by the end of the day, because the MPPTs (and other charging sources) adapt charge current lower to maintain Absorption voltage.
My priority is topping off the AGM bank to maintain battery health, but I’d love to redirect the surplus power to a secondary lithium battery.
I’ve considered using an Orion DC-DC charger to charge the secondary battery from the AGM bank (the charging sources are all connected directly to the AGM bank/bus bars), but it doesn’t seem like Orion chargers can adapt charge current based on input voltage.
I could just adjust the cutoff voltages so that the Orion only starts charging once Absorption voltage is reached, but my concern is that with a solar array, if the Orion starts charging at full current as soon as Absorption is hit, the input voltage will drop, and then it’ll just cycle on and off repeatedly, which doesn’t seem healthy.
Does anyone know if there’s a way for Orion to adapt it’s charge current to maintain voltage not only for the battery being charged, but also to maintain the input voltage, or if there’s a better way to charge this secondary battery?
I’m also open to suggestions for other victron products or accessories that might allow me to regulate current to maintain input voltage ahead of a DC-DC charger!
Hello @stonge . The idea may be to use a device like a CerboGx to monitor a Smartshunt to provide the SOC of the AGM bank. When the AGM bank reaches 100% SOC you could have a relay on the CerboGX close to switch on the Orion. If the SOC drops to a preset level the relay could open to switch off the Orion. You could simply use the generator start function of the CerboGX to make this happen straight of out of the box.
I need to actually adjust the current of the Orion, and not just trigger it on/off at full current, since I want to start taking advantage of excess solar power well before the AGMs are topped off, but I could still do something based on SOC or system voltage/amperage.
I’ll look into what kind of control options/programmability the Cerbo has when connected to the Orion XS.
Yes,
There is a way to do it but not validated from Victon. I use to use it once as emergency solution with one of my friend’s truck after they understand the installation was not correctly designed …
And they were in the south of Italia waiting to load the truck on a boat to Greece…
The Orion XS is doing the same… I’m waiting the 24V version or 24 to 12 V version … also for testing !!!
I also use it ti set MPPT current up with Node Red…
This may end up needing to be a separate topic, but do you know if you can create feedback loops with node red, for example if one measured voltage goes down, current limit also goes down?
Or are options with node red and Victron limited to more discrete/time-based actions?
