7 Mistakes For Off-Grid Solar Power Systems - Avoid These!

In this video, I'm going to show you the 7 common mistakes beginners make when building their own off-grid solar systems. Avoid these pitfalls to ensure your DIY solar project is efficient and reliable.

One common mistake is undersizing your system. Many people underestimate their battery and solar panel needs, leading to insufficient power. Perform a thorough load analysis before starting your design.

Another mistake is using a low battery voltage for high-power inverters, which can lead to higher costs. For instance, a 3000W inverter on a 12V system draws 250A, requiring expensive, thick cables. A 48V system reduces the current, allowing for cheaper, thinner cables.

Under sizing wires is another frequent issue. Incorrect wire insulation ratings can cause overheating. Use welding cables if possible or refer to a wire thickness table for alternatives.

Using incorrect fuses for voltage and ICC can compromise safety. A fuse rated for 32V cannot be used in a 48V system. Ensure the fuse can handle the maximum current in case of a short circuit.

Cheap lugs can lead to poor connections and potential failures. Always use branded materials from reputable companies to ensure reliable connections.

Non-branded fuses and breakers often lack proper testing and safety data, compromising system protection. Use high-quality, branded fuses and breakers from trusted manufacturers like Blue Sea Systems, Littlefuse, Bussman, Siemens, or Schneider.

Lastly, not respecting the discharge rate of a battery can significantly reduce its lifespan. Different battery types have specific charging and discharge rates. Follow the manufacturer’s guidelines to ensure optimal performance and longevity.

[junkerzn]

I liked this one! I couldn't find anything serious to critique this time. I'd just add, on spec'ing cable amperages, even if the insulation can handle high temps you still don't want high temps in your system for a variety of reasons. Most prominently, voltage drop and thermal cycling causing connections to loosen over time.

Under-sizing cables is mainly a legacy 12V issue where people with 12V systems just couldn't afford super-huge 4/0 cabling to handle the currents they wanted to work with. It is entirely unnecessary on a 24V or 48V system. So always use 60C or "AWG for power transmission" tables in higher-voltage systems.

-Matt

[timothyalanogrady]

Hello and thanks for letting us learn with you . I bought your book. And I'm been reading it and leaving a lot .

[sadiqyusuf]

Educative, i have learnt alot from you battery discharge explanation. It will sure help when i choose batteries for a setup.
Thank you sir.

[owolabiadeteye]

Thanks big boss for your devoted and educative lecture . Best regards . To carry out load analysis on a system with Switch mode power supply ( SMPS), Can one use the Amp and Voltage rating on the SMPS for load analysis. e.g adapter for laptop charging

[sjain]

Excellent information of Solar system design

[herbertvonsauerkrautunterh]

I just get the biggest of everything I can. I have a 12kw transformer inverter in fitting soon and currently 20kw of 48v battery. The inverter in using now is only 5.6kw. not enough. I will need to up size the battery to at least 50kw to make it worthwhile. I also have one victron rs450/100tr charge controller to start with.
I'll be going with 120mm2 cable and 300a nt2 blade fuse.
During any blackouts I can sell energy to the neighbours. At a free market rate of course😂

[jimfields]

Seems most videos concentrate more on either 12v or 48v systems. A detailed 24v split phase system video for temporary home backup would be awesome.

[icarus_ap]

melting cable, I learn this the hardway

[iohann.bab.]

I have a question who inverter companies don't give a good answer, they said you can charge your battery bank with external generator connecting to your inverter charger, what kind of wave they don't say, pure shine or square or modify, I think only pure shine, but most generators in the market still use square or modify.

[rafiullahhaqmal]

Good day sir,
I have 2 250W solar panels and one tall tubular 12v 240ah battery and a 30A charge controller,
I am using an egg incubator which runs 24/7 on AC 1000W inverter charger, my charge controller shows my usage 7A on average, sometimes it's not sufficient for my incubator and it turns off, so what could be the problem, please help on this regard.

[FrankDeGooijer]

Hi I have a 24V 240AH traction battery. Which converter can I connect to this and how many panels do I need at least to charge sufficiently?

[Lolo_BANGGE]

Hi @Cleversolarpower, this is Grandpa Emil, one of your avid subscribers in the Philippines.

Will it be possible to make a YT video about the proper way of charging and discharging powerstations? I am currently using a Pecron E1500LFP and since I pretty much would like to make the batteries last longer, I would want to know the proper way of charging/discharging/storing it.

There are several schools of thought on this matter which, instead of helping me, sadly, it made my brain explode:

(1) Some experts suggest to maintain at least 20% of its battery capacity before charging/topping it again for the next use. In relation to this, will it affect the one (1) cycle count if, say, I re-charge it back to 100% from 20% remaining viz zero percent because from what I've read, generally, a cycle is depleting the battery from 100% to 0%.

(2) On the other hand, some would advice to charge/top it to just around to 80% (not 100%) before its next use.

(3) Still, other experts would suggest that when storing LFP powerstaions, charge it between 40% to 50%. Then use it after 3 months of storage to maintain its battery life (roughly 3500+ battery cycles).

That said, based on your experience and hopefully thru actual tests concerning the same, can you please provide us in one of your future videos the proper way of charging/discharging/storing powerstations with LFP batteries or any other battery chemistry, for that matter? Thank you.

[erroneouscode]

Why is it that everyone that does such explanations with using a 3000w inverter on 12v and suggesting cable size and fuses etc with the equation of 3000/12 fails to take into account that battery voltage when low or reaching BMS or inverter cut off may fall to 10v or even 9v. Cable, fuse, and even your 1.25 safety factor margin are out the window without taking the lower voltages into account. It's simple to say don't build such high powered 12v systems but there's situations such as in smaller recreational vehicles where 24v or 48v does not make sense.

[Snerdles]

Only use lugs that cost at least one dollar...

"I think I have an idea for profitability!" - knockoff amazon seller