₦airaland Forum

chris81964:
I imported them from the US. I might have a few that arrived in Nigeria last week.

Are they for sale? I'm interested

makavele:
And that thing about voltage headroom . . . has only been discussed as user preference . . .
There is no hard fact or evidence that backs it up 100% . . . it is not etched in stone . . .
You can as well have a VOC of 250V on a 12V battery bank . . .
An MPPT controller will still do the conversion and downsizing very well . . .
There would be losses of course, same for a 45V Voc too . . . There will always be losses in the system.

So I've decided to return my hybrid inverter to get a MustPower 3kva and Fangpusun 100/50 MPPT controller. My calculations show that whether i do 2x2 or 1x4 for four 300W panels, the resulting current output will still be the same for the charge controller. Is this correct?

Where can I get PV cable for sale? Or can I just use regular 4mm² wires? This is for connecting the panels to my hybrid Inverter/Controller

NiyiOmoIyunade:
You have a 24v nominal battery bank.

A 2×2 nominal setup for your 24v panels combined with a good MPPT controller will ensure that the controller has sufficient 'headroom' to provide a output amps 'boost' by converting the excess voltage coming from your 2×2 series panels into useable amps going to charge your batteries or power your loads.

If properly setup you may expect 15% to 30% more power generated from thesame quantity/wattage of panels using an MPPT vs. a PWM controller in this your proposed 2×2 config.

Some watchouts - you have 2pcs 200ah batteries so you need at least 4pcs 300w panels except you plan to supplement solar charging with Gen or PHCN on a regular basis. I daresay you need at least 6 to 9 panels (yes 9 because I prefer you to do a 3×3 config to lock in that 'mppt headroom' I mentioned earlier) to really give you energy independence but how many panels you need will depend on your loads/power consumption sha.

If you do not plan to expand your battery bank or solar panel size much in the next two years then you can get by with a solid PWM controller and stick with your 300w panels all in parallel (1×1 config) - the 300w panels I have come across usually have a rated voltage/VmP of 35v to 36v - on a good day this will be sufficient to provide PWM charging to a 24v battery bank - if however you look at the panel specs and you see like 30v rated VmP then please buy your MPPT CC peacefully and do 2×2 or 3×3 series connection for your panels for better results. Be sure to buy a proper capable MPPT because they really are not born equal.

Overall for upgrade flexibility and overall ease and benefits I guess you should go with MPPT over PWM - you need to get so many things right e.g panel specs & config, cable gauge & length e.t.c to really enjoy PWM whereas MPPT is kind of more forgiving of mistakes (allows you to be lazy) and you will still get good results. Besides a solid American or European PWM controller costs just a little less than a decent chinese MPPT aka Fangpusun or EPSolar MPPT.

If you do choose MPPT please go for one that allows you to do a 3×3 panel config and then steps down the voltage to what your 24v nominal battery bank can handle - you will get best results that way.

Thanks Niyi

mcTrinity:
your first paragraph actually answers the question as to the advantage of MPPT over PWM.

Nevertheless, a 3x3 configuration would be very inefficient on a 24v system. 3x3 is good for a 48V system.
Remember MPPT conversion efficiency is best when the PV volt is not too far from the battery volt. for a 48v system, the conversion efficiency is better when the PV volt is between 75-95V. for a 24V system, the PV volt should be around 45-60.

with MPPT, the best configuration for a 24V system should be maximum of 2 in series (looking at 250-300w panel)

Also, since the load is just about 300w and it's just 2 batteries, 4 panels will be enough: 2x2 on MPPT or 1x4 connected either directly to the hybrid inverter or through a PWM controller.

Nevertheless, since it's a small setup, PWM will suffice. They work better in small setup compared to MPPT.
To me, MPPT on small setup is a waste. There are gurus that can explain better.

MY PERSONAL OPINION

Thanks
Cheers

I appreciate you guys taking the time to explain in details. Thanks

mcTrinity:
your Inverter has a 60VDC Voc max. so there's no way you can do 2 panels in series. for 2 batteries @260-350w load, you can use 3-4 panels, all connected in parallel.

If I get an external MPPT controller with high enough VOC, what advantages will a 2x2 setup for the panels give me, as against the 1x4?

Dam5reey:
You need minimum 4 panels, and also get an MPPT controller... The inbuilt controller is meant for support if you do have constant power..

Could you please explain this a bit? The user manual says there's an MPPT controller in it already.

mcTrinity:
your Inverter has a 60VDC Voc max. so there's no way you can do 2 panels in series. for 2 batteries @260-350w load, you can use 3-4 panels, all connected in parallel.

Thanks man!

mcTrinity:
I'll spare the mathematical explanation and do plain English explanation (Lolz).
whether you might need more panels depends on whether you're a heavy user. The two 300w panels (in parallel) might be okay since its just two batteries.

nevertheless, you can add another 2 panels and do 2x2 connection.. but you MUST confirm the Voc of the panels and cross check it with the maximum Voc of the inverter to avoid "stories that touch"

on the issue of future battery upgrade, you need to be very careful. it's not technically healthy to add old batteries to new batteries. Technically, you can still add within 2-3months (I stand to be corrected). personally, if my clients don't upgrade within 6-8weeks (I. e. 2months maximum), I don't upgrade again. they'll simply manage their existing bank or add solar system

THE ABOVE IS STRICTLY MY PERSONAL OPINION.

thanks

Attached are the specs for the new 3kva hybrid inverter and the 300W panels. My batteries are new (less than three weeks, i just changed them) and the total daily load is between 260W and 350W - no AC, no fridge, no cooker

Hello guys, I'm a new member. I've been using an inverter (Luminous EcoVolt 1500) for about a year now and I've decided to go solar because NEPA has become awfully unreliable and i cant get my batteries (2 x 12V 200AH connected in series) charged enough.

I bought a 3kVA hybrid inverter that claims to have an inbuilt Solar charge controller supporting 50A max, and 2x 300W 24V panels. What's the best way to arrange the panels to get my batteries charged in the shortest possible time? Do i need more panels?

If I want to add 2x more batteries in the future, will the system be able to accommodate it and what will need to change?