pv panels mixing

[Mauri Meere]

Hi

Right now in my 24volt system, I have 4 Kyocera 3amp 12volt 50watt modules(in series

for 48volt) is there a way to increase the array size by adding a couple of Hanwha 310watt

60cell modules or do I have to abandon the Kyocera's (which are still in good shape).

Thanks

[Rob Beckers]

Mauri, just put the two types on their own charge controllers. For the Kyoceras a simple PWM controller would do. It'll only be 4A into a 48V battery bank. For the Hanwhas you'll need an MPPT controller. Now for 48V you need at least 3 of those panels in series (it takes 144 solar cells in series to reliably charge a 48V battery bank). That means a 150V DC rated MPPT charge controller.

-RoB-

[Mauri Meere]

Thanks for the swift reply.

I should have given you more info. The battery bank is 24volts 250amp-hrs, connected to a Solar EP 2215BN MPPT controller, connected to a Trace U2624 inverter and the 48volt pv array.
I do have a 24volt PWM to use with the existing array that I can configure to a 24volt output from 48volts.
Can I get away with just 2 Hanwhas since the battery bank is 24volts? Can I add another Hanwha in the future?
I assume both controllers connected to the same battery will not cause a problem for the MT-50 remote meter.

Many thanks, Mauri

ps Just saw your reply to my other post. My apologies for creating the confusion.

[Rob Beckers]

Mauri, yes, two Hanwha panels (60-cell each) are enough to charge a 24V battery bank. It takes at least 72 solar cells to do that, so two in series gives you 120 cells to charge with and the EP Solar charge controller will take care of converting the Voltage down to battery value.

You can indeed add a third (in series) to the two at a later date. That would give you around 900 Watt of solar, and into a 24V battery bank that works out to around 32 Amp maximum. The controller will clip at 20 Amp, so on a really sunny day you will not use the full potential of the extra panel. On cloudy and winter days the extra panel will pull its weight though.

Three 60-cell panels in series is the maximum for this EP Solar controller, it has a maximum of 150V for its PV input, and each panel can reach about 45 Volt on a really cold day.

-RoB-

[Mauri Meere]

Hi Rob
Thank you for that ....my plan/design is slow moving forward.

Can you comment on my last statement in my previous message...'I assume both controllers connected to the same battery will not cause a problem for the MT-50 remote meter'. Since the MT-50 is connected only to the 2215BN controller.

[Rob Beckers]

The MT50 will only display information about the controller it's connected to. So you'll see PV and battery Voltage that the 2215BN sees, and the currents. It won't show anything about the other controller.

-RoB-

[Mauri Meere]

I want to make sure I understand the last post correctly.

The MT-50 displays the reading from the PV that the 2215BN are connected to and also the battery readings that the 2215BN is connected to which include the contributions from the PWM in parallel with the 2215BM.

[Rob Beckers]

There's just one battery Voltage, regardless how many things you connect to those batteries. Charge with lots of stuff and the battery Voltage rises, put heavy loads on and it lowers. Each charge controller sees/measures the same battery Voltage (barring measurement errors and line losses).

-RoB-

[Mauri Meere]

Thanks Rob for the verification.