Need help with charging...

anbusanbus Registered Users Posts: 7
Hi guys, i am new to this forum.I need your knowledge.

I have 3 modules 100 watt each. 18Voc/6A Isc

Phocos CNX 40A my charge controller.

4 12V 100Ah lead acid bateries.

I had connect my modules parallel, so i have 12volt/18A at the charge controller.
My baterry bank is also wired in parallel,so i have 12Volt/400Ah.

My question is whether the 18A from my pv array are too high for my baterry bank.Will this affect their life, or the charge controller takes care of it?

What should be the proper Amperes 'passing' into the baterries for a proper charging?

(My inverter is Cotek SK-12 1500watt)

Waiting for your answer...


  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Need help with charging...
    anbus wrote: »

    My question is whether the 18A from my pv array are too high for my baterry bank.

    No, too low.
    First off, it is rare that your panels will actually put out their full current. On average, it will be about 80% efficient so: 300 Watts @ 80% = 240 Watts / 14.2 Volts (for charging) = 16.9 Amps.
    But a 400 Amp/hour battery bank should be charge at a minimum rate of 5%, which is 20 Amps. For preference, 10% would be better.

    Your charge controller will limit the current and Voltage to the batteries: a 40 Amp charger means no more than 40 Amps will go to the batteries no matter how much Wattage is available from the panels. It will have Voltage levels set to reduce or shut off the current (depending on the charger) as the batteries hit the appropriate charge level. I've never heard of that particular controller so I can't give you any more definite details.

    In short, what will ruin your batteries in this set-up is chronic under-charging.
  • icarusicarus Solar Expert Posts: 5,436 ✭✭✭✭
    Re: Need help with charging...

    I suggest that your read and understand the following links:
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