How best to do it

[eastpoint turbine]

 Hi to all ,I have six 24 volt solar panels all not the same wattage  but close. i want to know the best way to wire them up for a 24 volt system
i have 600 Ah battery ,  Magna sine 4024 psa inverter   i do not have a charge controller as yet  will be about 6 to 7 weeks before i get one.
   Should i wire all the neg together to the batt neg  and all the pos to the batt pos?  I do not understand much about sets and strings .  Advise would be deeply appreciated
ps the controller on order is the midnite classic 150
    Jason

[Westbranch]

WAIT for the controller, DO NOT connect them directly to the bank or you will some bad things to it and probably have to replace it...

[eastpoint turbine]

Thanks for the reply  but i erred in my first post  i wanted to say i Already have 4 panels connected and working  and wanted to know  how best to add 2 more   
  Very sorry for the misleading post 
Jason

[Westbranch]

what controller do you have now?

[eastpoint turbine]

As i said i do not have a controller  4 panels are wired directly to the batt

[Westbranch]

back to my first post....  don't do that... you can damage the batteries by hitting them with too much voltage!

Are the panels in series or parallel?
What are the specs of those panels? Voc Vmp Ioc Imp?

[eastpoint turbine]

Thanks for taking the time with me   as you asked
voc=37.6                             vmp=30.4
isc=9.09
these are the specs on the panels which are wired in parallel. as i write this now  the panels are putting 25+ amps into the batt ,  these were wire so for the past 6 to 7 months
  Some don't agree with wiring direct to the batt  others say it's ok, depending ? i want to add 2 more panels  someone told me not to wire more than 3 panels to a string   so with 6 panels how should i go about it

[Westbranch]

If you go here http://www.midnitesolar.com/sizingTool/displaySizing.php  and plug in your specifics, you will determine the array configuration,  looks like 3 in series in 2 parallel arrays

[Vic]

Hi eastpoint,

First,  more than two strings of PVs must have a DC rated circuit breaker of fuse for EACH string.  In your case, now,  each PV module is a string,  so your existing PV array should have four breakers/fuses,  and when adding PVs,  each new string needs a new fuse/breaker.

And if you have no formal Charge Controller,  you are it.  Your present configuration of strings of one PV is probably the best -- it allows the most current from the array.

But,  YOU must watch the battery voltage,  and temeprature,  and remove the PV connection to the battery when voltage is at the correct point.  This point depends upon the battery that you are charging.  If you have a DC Disconnect/circuit breaker between the PV fuses/breakers,  it will make the process of connecting and removing the PV power from the battery.

If you could possibly borrow a Charge Controller form someone while you wait for your Classic,  you would be far ahead,  as damage CAN occur to batteries when there is a charge source that is not controlled by barrery voltage,  and current demands on the batteries.

It is safest to just do the Bulk part of the charge if you have no CC,  and perhaps weekly,  try to do a manual Absorption stage.

If your batteries are Sealed -- AGM or Gel -- then management of voltage and for Gels,  charge current can be very important.

It is ALWAYS best to use a good CC to manage battery charging.  If you have grid power or a genset,  using your Inverter should be safer,  once the correct charge set-points are entered into the inverter.  Many,  DO suggest connecting the PV array directly to the battery in the event of a CC failure,  but charge management can require several hours per day in this case. 

When you get your Classic,  then,  strings of two PV should be fine.  Three per string should be OK -- a bit high on a 24 V battery, but should be fine.  Opinions,   Good Luck,  Vic

[zoneblue]

The danger of putting 1KW into your bank continuously is this:

1. large quantities of hydrogen and oxygen are created, creating a explosion risk.
2. positive plate grid corosion, permanently reduces the cell capacity.
3. boiling the electrolyte dry can do some real  bad things to the exposed plates, like chunks of plate flaking off, fall to the bottom of the cell and short the cell out.
4. thermal runaway, temps increase, voltage increases temps increase, meltdown, boom!
5. If they are AGM, they are or will be toast as soon as the valves pop at around 30 volts.

If they are wet/flooded, then add water diligently. Manually disconnect them as mentioned above when they reach the absorb set point, (28.8V for mine) look up what yours should be.

You have in your possession some mighty dangerous gear.  Get a controller!!