Mixing different solar panels, i.e., voltages?

[Don101]

Hi, I'm a little new to solar, although I have some Harbor Freight panels. I'm wanting to purchase a 245 watt, 37.8 volt panel. Question is: could two (2) of the H.F. panels be wired in series (they are 21-22volt panels) and wired together in parallel with the 245 watt panel? Or even 2 to 3 sets of 2 H.F. panels wired in series parallel with the 245 watt panel?
Appreciate any help, thanks!

[SunEagle]

Hi, I'm a little new to solar, although I have some Harbor Freight panels. I'm wanting to purchase a 245 watt, 37.8 volt panel. Question is: could two (2) of the H.F. panels be wired in series (they are 21-22volt panels) and wired together in parallel with the 245 watt panel? Or even 2 to 3 sets of 2 H.F. panels wired in series parallel with the 245 watt panel?
Appreciate any help, thanks!

Hello Don and Welcome to Solar Panel Talk.

My brief answer is no.

The reason is that those HF panels are only 15 watts each and generate very little amps. While you can mix different wattage panels in the same system the differences in the Vmp and Imp ratings can only be around 5%.

So even if you could "duplicate" the voltage of the 245 watt panel by wiring a number of other panels in series there would still be a big difference of the Imp between the two.

[Don101]

Thanks!

Thank You very much for the expert advice! I now know what I need to do without fouling up my system. ...Oh, by-the-way, one other question: since I will be using 200 plus wattage panels, thus, higher voltage going into my charge controller, which is 12/24V. rated. I would have my batteries wired in series (24V) to accept the 24V. from the c. controller, yes? However, I already have a 12V. inverter! What can I do about that, anything? Do I have to buy a 24V. inverter?

Appreciate your help (again!), thanks!

[mschulz]

Thank You very much for the expert advice! I now know what I need to do without fouling up my system. ...Oh, by-the-way, one other question: since I will be using 200 plus wattage panels, thus, higher voltage going into my charge controller, which is 12/24V. rated. I would have my batteries wired in series (24V) to accept the 24V. from the c. controller, yes? However, I already have a 12V. inverter! What can I do about that, anything? Do I have to buy a 24V. inverter?

Appreciate your help (again!), thanks!

Yep when you rewired to 24 volt, your inverter will have to be 24 volt as well.

[Wy_White_Wolf]

Thank You very much for the expert advice! I now know what I need to do without fouling up my system. ...Oh, by-the-way, one other question: since I will be using 200 plus wattage panels, thus, higher voltage going into my charge controller, which is 12/24V. rated. I would have my batteries wired in series (24V) to accept the 24V. from the c. controller, yes? However, I already have a 12V. inverter! What can I do about that, anything? Do I have to buy a 24V. inverter?

Appreciate your help (again!), thanks!

Or you can keep the batteries and inverter at 12v and buy an MPPT charge controller

WWW

[Don101]

Use of a MPPT charge controller?

I asked the question about using 24 volt panels and the need of having the batteries in series equaling 24 V. Thus, would the inverter used have to be a 24 V. also? Yet, one said if a MPPT charge controller is used batteries can be set at 12 V. and a 12 V. inverter, true? And why is this? (I will be using a MPPT c.c.)

[Amy@altE]

Most (not all) MPPT charge controllers can take a higher voltage panel and reduce it to 12V battery. What model charge controller are you using?

[Don101]

Charge Controller

I'm purchasing a Eco-Worthy 12/24 V. MPPT charge controller. I ordered it over this weekend, haven't received it yet. Read many reviews about it and it is a true MPPT controller (many are not!). Hopefully it will serve me well.
This info. you gave is very helpful in knowing the extra expense will not be necessary for the inverter upgrade. Thanks sooooo much!

[SunEagle]

Most (not all) MPPT charge controllers can take a higher voltage panel and reduce it to 12V battery. What model charge controller are you using?

His charge controller is probably the one that comes with those HF panels.

I don't think it can charge a 24volt battery and I also think there is a maximum of 4 to 6 of those 15 watt panels that can be connected to it. Although I could be wrong.

[Amy@altE]

His charge controller is probably the one that comes with those HF panels.

I don't think it can charge a 24volt battery and I also think there is a maximum of 4 to 6 of those 15 watt panels that can be connected to it. Although I could be wrong.

I thought the HF panels were off the table.

[SunEagle]

I thought the HF panels were off the table.

They should be. When I posted he also posted and it looks like he is going to purchase an Eco-Worthy

[Amy@altE]

That EcoWorthy can handle Voc up to 42V, so he can use it with the one big panel for 12V battery.