Solar Panel Mix and Match?

[Tday01]

I recently broke a Kyocera KD135SX-UPU on my 5 panel array. I am finding it hard to source here. Is it possible to mix and match with other brands / sizes?

Thanks,

Tony

[zeehag]

electricity doesnt understand brand names.
mine are a mixmatched unset--they have functioned well for a long time--over 4 years, so far.

[Sumner]

What kind of controller do you have? MPPT or PWM? The MPPT will be more efficient if the panels are close to the same operating voltage and the same cell type. Are your panels 12 volt panels (operating at 17-18v)?

Sum

[zeehag]

my controller/regulator is a pwm by bz industries...now that i know it better, i actually like it...

[hellosailor]

Tony, is your array series? Parallel? Combo? Voltage?

In theory you can mix and match and as long as the odd panel is somewhat similar, as many will be, it will work better than having nothing. Depends on what your whole setup is though, there's always some exception to a rule.

You need to fill in the blanks to get a real answer.

[senormechanico]

If they're in a parallel string, it won't matter much.
Series, you need to be a lot more matched.

[Tday01]

Just got back to internet!

The controller is MPPT. They are 12 V panels operating at 17V. I think it is parallel.

Tony

[daddle]

Parallel must be okay if all the panels are manufactured with the intention of charging 12V (nominal) batteries. With or without an MPPT. I.e. nominal 18V panels. As an ex-EE, given my limited understanding of the electronic behavior of solar panels (the equivalent circuit of current source, resistive elements and possible bypass) I would not run different panels in series without some professional advice.

[Sumner]

Originally Posted by Tday01

Just got back to internet!

The controller is MPPT. They are 12 V panels operating at 17V. I think it is parallel.

Tony

You should be fine with any other 12 v. panel that is operating near the same voltage as the others.

We have a ....



http://purplesagetradingpost.com/sum...justable-1.jpg

.... 40, 60 and 100 on our Mac on an Blue Sky MPPT and it works great.

On the Endeavour...



Endeavour 37 Electrical Mods Index

...they are all 80's on another Blue Sky MPPT,

Sum

[noelex 77]

Originally Posted by Tday01

Just got back to internet!

The controller is MPPT. They are 12 V panels operating at 17V. I think it is parallel.

Tony

Look for the same Vmp (ideally work this out for a realistic, say 40degC panel temperature). The closer the better, but make sure it's within 0.5v.
Many panels will match this criterion.
If you are unsure post the panel you are considerng an I will look up the specifications.

[hellosailor]

"Look for the same Vmp"
Because: the MPPT controller "tunes" itself to match what it sees as the Vmp of the solar panels, and if your panels have different Vmp values, the MPPT cannot work at peak efficiency. It will still work, but if I had to guess I'd guess it could lose 5-10% power if the Vmp differences confused it badly enough to really mess it up. And I'd guess that the impact would be less than that, since the four other panels would tend to swamp out any minor differences from the fifth, making a single-digit loss more likely. (Now, ask me to guess which drawer your socks are in.<G>)

If you have to wait a bit to get a good match...how's your power holding up meanwhile?

[Tday01]

Thanks for all of the replies. Power is sort of holding up. Five panels would just exceed the boat draw, now we just lose.

We have been cruising San Blas for the last month, so no shore power to keep everything up.

The panels are nothing to the hassles we have had with our battery charge