12v battery/ 12./24v MPPT ~ 24v PV Panel

Hi,

Switch off the panels. Move leads on controller to the 24 volt battery, switch on panels.

For twelve volt--repeat as above but connecting to 12 volt bank.

2oldman wrote:
Your controller?

If that is your controller, then no, it's only rated for 12v. At least that's how I read it.

That is it, without the "Well See" logo ~ I paid $49.95 plus $11.90 S&H from www.tektrumcorp.com.

If I am not going to blow up something, I'll try it later on the RV batts. If (and if means perhaps yes) it will output 12v or 24v charging from the 24v panel, that sounds good to me. Then maybe I'll like the MPPT and for go the use of the PWM I have coming. Knowing me, I'll try them both.

Thanks for the post. And all others also get a thanks.

Floyd

If the unit is the one above in 2oldman's link then the way I read the specifications. You are good to go it should auto sense and work on both voltage ranges

Connect the battery (load side) first so for the RV connect to 12 Battery then connect the panel - if should do it's thing

Second disconnect the above and connect the unit to the 24 volt battery then to the PV panel it should auto sense the operating voltage and be good to go

No way to do both at the same time

Your controller?

If that is your controller, then no, it's only rated for 12v. At least that's how I read it.

My 12/24 PWM controller is like that. You connect to battery first, its little brain notices whether voltage us under 17v, if so it says must be a 12v battery and sets for that. If it sees 17 or more it says must be 24v and sets up for that. Now you can connect the array.

Now here is the fun part. With my PWM on a battery it will get Isc of the panel. Isc on a 120v 12v panel is 6.7a approx., and that's what you get. But if the panel were 24v Isc would be half that so lets say 3.35a. Now all the 12v batts will get is that 3.3a

BUT if I had 24v batts and my 12/24 controller and a 24v 120v panel, I would still only get that 3.3a but now that is just as good on the 24v battery as 6.7a was on the 12v battery.

Now the interesting part--what if that controller were MPPT instead of PWM? Aha. Now with the 24v panel and the 12v battery, you will get something like that 6.7a instead of just the 3.3. In fact you could get 10% more than 6.7a because it is that magical MPPT. (maybe 7.37 amps)

Just try it out and see what happens. :)

More info' on the MPPT As for a the maker,it's made in China:@ On the face, MPPT15 Solar controller CE~RoHS. On the back12v/24v-15a Be sure to connect the battery first then the load and the solar panel last.
The Batts, Scooter, 24v sealed lead/acid, okay for air transport. The RV batts are 12v flooded lead acid.

Hmm, it is me the O&S. Well, I have a 12/24v 15a MPPT controller and a 24v Panel. I bought ithe two for use with my 24v e/scooter which is 24v. Now, I would like to use the 12v/24v/MPPT and the 24v panel to charge the RV 12v Batts.

What brand and model MPPT controller do you have? There are a lot of MPPT controllers that can charge both a 12 and 24 volt battery bank

Becareful though. Most solar controllers are set up to charge using a lead acid battery type charging profile. I doubt your scooter has a lead acid technology battery and no clue if a lead acid technology charging profile would work with it.

Most MPPT that charge different battery voltages will auto detect the correct voltage. But you need to connect in the correct sequence as described in the manual. Otherwise if it is in the description it will work fine.

May as well post the full controller make and model number.

You cannot charge 12v and 24v battery at the same time. One or the other.

I must be old and slow too, because I'm having a hard time understanding the question.

I guess you're saying: can you just simply hookup the controller to either a 12v or 24v battery? If the manual says so, then yes. I do not know if your controller outputs 24v, or if that just means it will accept 12 or 24v of input.