More battery or more panels?

[sdold]

Steve I think you have a typo and meant if you wire the panels in parallel would need fuses.

I did, thanks for catching that.

[littleharbor]

I would get a 30amp unit. There are a number of good ones but none are really cheap. Midnite and Blue Sky make then. Possible the cheapest is made by Victron. Some people swear by Renogy but I think they are at the bottom of the quality scale.

Watch out for the low max voc. of Blue Sky charge controllers. There's no practical way to series wire panels in a 24 volt system for max MPPT input voltage without going over their 57 volt max voc. Ex. 2-72 cell (24 volt) panels. Approx. 90 voc. 3 -36 cell (12 volt) panels, approx. 63 voc. 2-60 cell panels, approx. 72 voc. This low voc. limit on these controllers never made sense to me. They are fine for using 24 volt panels for a 12 volt system but even the model number, "Solar Boost 3024i" indicates it's intended for a 24 volt system. They do seem to be well built quality units otherwise.

Output Current Rating 30 Amp maximum, automatic 30 Amp current limit Nominal Battery Voltage 12 / 24VDC PV Input Voltage 57VDC maximum

[SunEagle]

Watch out for the low max voc. of Blue Sky charge controllers. There's no practical way to series wire panels in a 24 volt system for max MPPT input voltage without going over their 57 volt max voc. Ex. 2-72 cell (24 volt) panels. Approx. 90 voc. 3 -36 cell (12 volt) panels, approx. 63 voc. 2-60 cell panels, approx. 72 voc. This low voc. limit on these controllers never made sense to me. They are fine for using 24 volt panels for a 12 volt system but even the model number, "Solar Boost 3024i" indicates it's intended for a 24 volt system. They do seem to be well built quality units otherwise.

Output Current Rating 30 Amp maximum, automatic 30 Amp current limit Nominal Battery Voltage 12 / 24VDC PV Input Voltage 57VDC maximum

Thanks for the info.

[Sunking]

Watch out for the low max voc. of Blue Sky charge controllers. There's no practical way to series wire panels in a 24 volt system for max MPPT input voltage without going over their 57 volt max voc.

What does that tell an informed consumer?

Answer, it is Chi-Com junk not made to work in a real world.

[littleharbor]

What does that tell an informed consumer?

Answer, it is Chi-Com junk not made to work in a real world.

Blue Sky controllers are not chi-com. US made.
Blue sky controllers..jpg

[georgia088]

Ok, I’m a little confused. Should I be wiring up my panels in series to provide a higher voltage to the charge controller if I’m going to get an mppt? Also, I see you are calling blue sky chargers junk and some think the Renogy is junk.... so what would be my best bang for my buck for around 400 watts of panels?

[SunEagle]

Ok, I’m a little confused. Should I be wiring up my panels in series to provide a higher voltage to the charge controller if I’m going to get an mppt? Also, I see you are calling blue sky chargers junk and some think the Renogy is junk.... so what would be my best bang for my buck for around 400 watts of panels?

If I was spending the money I would get the MidNite solar Kid. It is less than $400 and for a 30amp MPPT CC it has a lot of bells and whistles that can be set to charge a wide verity of battery voltages along with having an 150V DC input rating

[Sunking]

Blue Sky controllers are not chi-com. US made.
Blue sky controllers..jpg

OK my bad, point is the input voltage is not practical.

[littleharbor]

OK my bad, point is the input voltage is not practical.

Yes, not to be confused with the "Make Sky Blue" chi-com crap.

[AndrewCoates]

300W at 18V is 16.7Amp, so you would need at least a 20Amp MPPT charge controller.
If you want to have some margin or go to 400W solar, then 30Amp would be better.
Some will support a single battery type, some will support different ones, Consider that if you want to future proof your system.

After looking at the cost differences between the EPEVER product and what I paid for my first solar controller "US product" I figured what the heck! I gave it a try. And I gotta tell ya, I am impressed with this EPEVER MPPT 30 amp charger!