Mixing Panel Types and Voltages

[AWEATON]

I currently have a system with two 255watt 24volt Renogy Polychrystaline panels.  I want to add to that but the panels I bought are no longer available.  What I would like to know is this: Is it possible to mix Polychrystaline with Monochrystaline type panels?  Is it possible to mix voltages with 12 and 24 volt panels in the same system?

Thanks,
Allan

 

[Trebor English]

The original two panels have a charge controller.  You can add more panels of any kind or any voltage with another charge controller.  

Parallel mixing might work if both types have the same number of cells and the same type of cells.  Series mixing might work if they are the same current.  A separate charge controller for the new ones is your best option.

 

[AWEATON]

I currently have a system with two 255watt 24volt Renogy Polychrystaline panels.  I want to add to that but the panels I bought are no longer available.  What I would like to know is this: Is it possible to mix Polychrystaline with Monochrystaline type panels?  Is it possible to mix voltages with 12 and 24 volt panels in the same system?

Thanks,
Allan

Thanks for the reply Trebor.  I have more batteries than the current system can keep charged.  If I split them up into two groups with another charge controller, could I then wire the batteries into my existing inverter?

Thanks,
Allan

 

[Trebor English]

I wouldn't split up the battery bank.  The original controller can supply 25 amps and the new one can supply 20.  The battery bank will get the sum of the two.  That way all batteries charge and all participate in powering loads.  

Without a doubt one charge controller will be different from the other.  That doesn't matter.  When the battery bank is tapering down to 3 amps it doesn't matter if that comes 1.5 amps each controller or 3 from one or 3 from the other.  The lead sulfate converting to lead and sulfuric acid doesn't care.

 

[AWEATON]

Thanks for the reply Trebor.  I have more batteries than the current system can keep charged.  If I split them up into two groups with another charge controller, could I then wire the batteries into my existing inverter?

Thanks,
Allan

 

[AWEATON]

That's good news. I didn''t say in my original post, but all 6 of my batteries are 12v 125ah AGM, all the same age and same manufacturer (VmaxTanks). My controller is a 40amp MPPT 100volt input. (Epever) So it sounds like this should be a pretty easy upgrade. I appreciate your help.

Thanks
Allan

 

[frater secessus]

Yes, the two controllers can feed power to the house bank no matter how their respective panels are set up.  I'd set both controllers to the same setpoints (absorption, float, etc).  

More info on multi-controller charging.

 

[DLTooley]

Yes, the two controllers can feed power to the house bank no matter how their respective panels are set up.  I'd set both controllers to the same setpoints (absorption, float, etc).  

More info on multi-controller charging

 

[Trebor English]

I'd set both controllers to the same setpoints

My point was that same brand controllers, exact same programming, same battery, there will be behavior differences.  Spend zero time and energy trying to make them the same.  It doesn't matter.  If you get a different controller this time, the difference doesn't matter.  Don't limit your panel voltage choice or controller choice to what you had before just to try to make them charge equally.  

You do want all 6 batteries to charge the same, exactly the same.  That's different.

 

[John61CT]

Do **not** split the bank, very important.

The only "matching" of panels needs to be when you have more than one per controller, match within that set, ideally same model panel.

The multiple chargers, SCs, whatever connected to your bank don't need to match at all, and no problem with them running concurrently.

Each should output suitable charge specs as per the batt mfg.

They don't need to have the same setpoints, but if that's easy would make sense.