Problem: three 48V solar instalations and one 48V battery bank

[kermitas]

Dear community,

I started this new thread to resolve problem described in my second thread (http://www.solarpaneltalk.com/showthread.php?t=1754, thank you Mike90250 for your help).

Here is hypotetical situation :
- I have three 48V solar instalations (really it gives more than 48V, lets say 55-60V)
- all three instalations are differently located to the sun (when one gets full sun, second one is in half-shadow, and third one is in fully shadowed)
- I want to accumulate all power in one 48V battery bank (for example four accumulators)
- I want to use MPPT charge controllers

Do I have use separate charge controllers, one for every instalation ?

What about bad interaction between controllers ?

- when one controller will give power and second one will also give accumulators can get to much energy in one time
- when one controller will give power and second one will do accumulators probe and receive information that it should go to sleep mode because accumulators are fine (and true is that there are not)

In first one we can give to much power to accumulators and destroy them after few years.

In second one when every collected energy is important ... second controller states that accumulators are fine and stops charging.

Maybe shoud I connect all three instalation serially ??
But votlage will be high (potentailly 3*60V = 180V) !!!
One istalation will hive 7A, second one will give 4A and last one will give 1A - I don't what is real A received.

Maybe shoud I connect all three instalations parallely ??
But what would happen when one one instalation will get good sun and give 60V 7A and second one will be in shadow and give 47V 2A ??
Even if I use blocking dioded will power from this second one installation be usefull ?? Or maybe it will be wasted ??

---

I am waiting for ideas how you will resolve problems with those three pv instalations. What is important to me is to use MPPT charge controllers because I am planning to over-voltage every of my installation (I have a lot very bad days here with no sun).

Thank you very much,
Arthur.

[Mike90250]

1) I don't understand word " akkus ".

You can use one PWM controller, and panels in parallel

OR

You can use 3 MPPT controllers, one for each array, a charge controller can get fooled when part of an array is shaded. Charge controllers have blocking diode inside.

DO NOT connect the panels serially. You will get very little power, and burn out the charge controller from the high voltage.

There will be little or no bad interaction between 3 charge controllers. you have said only 1 panel will be in good sun at a time, so you will not over amp your battery.

[kermitas]

1) I don't understand word " akkus ".

You can use one PWM controller, and panels in parallel

OR

You can use 3 MPPT controllers, one for each array, a charge controller can get fooled when part of an array is shaded. Charge controllers have blocking diode inside.

DO NOT connect the panels serially. You will get very little power, and burn out the charge controller from the high voltage.

There will be little or no bad interaction between 3 charge controllers. you have said only 1 panel will be in good sun at a time, so you will not over amp your battery.

Thanks Mike.

'Akkus' chagned to 'accumulators'.

Two of my instalations can have almost the some location (one can be very little shadowed by little bushes).

(I used three possible localizations - 'full', 'half' and 'zero' to the sun - just for example.)

I didn't know that having more than one pv instalation can make so much problems .

As I counted I can make pv instalations at (in order that I am planning to build use) :
- four fences *
- one big wall *
- roof

* - very good direction to the sun

Thanks,
Arthur.

[photovoltaik]

Nice post... interesting !

[Mike90250]

Nice post... interesting !

Mod's are keeping an eye on folks posting, that contribute nothing to the conversation. just in case you are building post count for spam....

[Sunking]

Mod's are keeping an eye on folks posting, that contribute nothing to the conversation. just in case you are building post count for spam....

I was going to warn you about this joker, he showed up on another forum I moderate, ran up post count, then SPAMMED every member with PM. Kill it now before it grows up.

[DeltaFox 25]

Hy Mike could he use a sun tracker , then his 3 panels would have power all the time.?

[Mike90250]

A tracker could be used, but if he has enough panels to meet his demand, why add a easily broken gadget to the mix?