getting closer this time, I hope...

[whazzatt]

In the past I started by asking what options my equipment afforded me. Now I'm going to specify a small load first. Five 4 watt lights running for six hours per night, so 120 watt hours. Add a but for inefficiencies, so 140 watt hours. Two day autonomy (I'm in sunny South Africa) so 140*2*2 = 560.

560/24=23.3 so make it 24 Ah needed for battery bank.

Looks like I can get four 12Ah 12V batteries at a good price; my reading makes me think I can put two in series for one string, and another two in series for another string, then connecting in parallel, making 24Ah at 24V.

Now to the panel and the CC. I was given a 130W panel with the spec sheet (link) saying it's 24V. Already have a PWM 10A charge controller. I know from a previous topic I tarted that the panel will only operate at 90W with the PWM on the 24V battery bank. I'm happy with this.

I used a site to calculate that the 90W from the panel will take 3.5 to 4 hours to charge the batteries from 50% dod assuming good light. An additional thought here is to double the Ah and get two 45 Ah 12V batteries, connect them in series, which would presumably charge in 7-8 hours?

To connect the 12V lights to the 24V battery bank, I expect that I'll need a 24V to 12V converter of some kind.

Any confirmation or correction of my thinking welcome...

Back of panel:
2 info back of panel.jpg

[Mike90250]

That's a nice 41V 4A PV panel
What else have you got, or what are you trying to do ?

[SunEagle]

IMO those panels have high Voc and low wattage ratings which would complicate any large wattage installation (on or off grid) due to the multiple strings needed to stay below the MAX DC voltage rating of any type of inverter.

They may also be obsolete and no longer supported by Tenesol.

[whazzatt]

Removed due to posting and editing issues.

[SunEagle]

Something went seriously wrong with my first post! Let's try this again:

I have asked questions about my equipment and 'options' they provide me before, but it got messy so I am going to have another go here after having done a lot more reading

A couple of your posts went to the Mod review process before they become available for everyone to see. I am not sure why but it usually happens when you attach a link or document that is not recognized as being safe.

[whazzatt]

Removed due to posting and editing issues.

[whazzatt]

Removed due to posting and editing issues.

[whazzatt]

Seems like I can't copy-paste ANYTHING into the posting boxes. I originally wrote the first post elsewhere and copy-pasted it in; tried from two different word processors, no luck. Had to write it all from scratch while in the forum posting box.