UPDATE--more test results in the "oh no" thread--a new meaning for MPPT?Reported initial results today at the end of the "Oh No MPPT" thread

How about a link to that thread there bubba? :)

here's the deal for me. I have the ' Technology Comparison' from Morningstar PWM charge control/MPPT charge control ~ "Typically recommended for use in smaller systems where 'boost' benefits are minimal' MPPT ~ 170w or higher to take advantage of 'boost' benefits more. Me thinks the 'go cheapo folks' are correct for less than 170w as per MS. All will no doubt agree that for large arrays the real (whatever that is is) MPPT is the right way to proceed.Added side note; I have the 20a CMTP02 ready to be tested soon.

What am I hearing here... I know I need lets say 14.4VDC @ 20AMPS per battery to be able to recharge that battery from a 50% charge state to a 90% charge state or more in a three to four hour time frame..I think I am hearing that the PANELS are usually rated at 5-7AMPS of usable DC current available which is a big killer of getting the batteries back to a 90$ charge state but by running higher DC voltages from the panels will produce alot more current than the rated 5-7AMPS and possibly end up with 14.4VDC charging DC Voltages at a higher DC Current rate.i.e. the controller will run at max with much the higher DC Voltages coming from the panel and produce higher DC current then using BUCK BOOST couple this back to the 14.4VDC at a higher DC current. I know I am not explaining this right but is something like this going on with the controller you are testing. My recent planning is looking at two 100WATT or 120WATT portable panels coupled with a permanent 120WATT panel mounted on my POPUP roof. The normal rated DC output of the these panels specs using the standard type controllers will not produce a usable 14.4VDC at a high enough DC CURRENT to re-charge my batteries in the short 4-5 hours of the panels being in high sunlight in ONE DAY...Think I am hearing something different now from these tests being performed.Roy ken

Just boil it out.PWM, amps, watts to battery.MPPT, amps, watts to battery.

RoyB wrote:What am I hearing here... I know I need lets say 14.4VDC @ 20AMPS per battery to be able to recharge that battery from a 50% charge state to a 90% charge state or more in a three to four hour time frame..I think I am hearing that the PANELS are usually rated at 5-7AMPS of usable DC current available which is a big killer of getting the batteries back to a 90$ charge state but by running higher DC voltages from the panels will produce alot more current than the rated 5-7AMPS and possibly end up with 14.4VDC charging DC Voltages at a higher DC Current rate.i.e. the controller will run at max with much the higher DC Voltages coming from the panel and produce higher DC current then using BUCK BOOST couple this back to the 14.4VDC at a higher DC current. I know I am not explaining this right but is something like this going on with the controller you are testing. My recent planning is looking at two 100WATT or 120WATT portable panels coupled with a permanent 120WATT panel mounted on my POPUP roof. The normal rated DC output of the these panels specs using the standard type controllers will not produce a usable 14.4VDC at a high enough DC CURRENT to re-charge my batteries in the short 4-5 hours of the panels being in high sunlight in ONE DAY...Think I am hearing something different now from these tests being performed.Roy kenBesides the advantage of the MPPT control, a user will get usable current from the modules on the shoulders of that 4-5 hours a day. My 235w module is still trickling at sundown.

Testing the ??MPPT ?? CMTP02 Controller UPDATE

17 Replies

BFL13
Explorer II
Sep 10, 2013
added some test results in other thread. Possible new meaning for MPPT too.
Old___Slow
Explorer
Sep 10, 2013
RJ,

I've always found you right on the 'Money'

O$S
RJsfishin
Explorer
Sep 10, 2013
I keep forgettin I dint want that controller in the first place, won the bid accidently. Refund sounding better all the time.:)
Old___Slow
Explorer
Sep 10, 2013
RJsfishin wrote:
Ok, sorry I started that thread, but the worst part is I never got that MPPT controller ! This is the first time I ever had any trouble w/ shipment, local or overseas. They want to give me a refund, but I told'm I want what I ordered.
Now they want me to wait another week before they settle. But it seems like I'll never see anything but the refund.

Rich,

Your one of my main men. Some call me old moldy. I guess for a reason. Great to save a 'buck'

Now RJ, I just looked on Ebay. One seller shows the MPPT 15a like you ordered @ $12.88 another shows $13.86 Please, you might just go after one more. My 20a arrived in 10 days. This happens to be one of the high volume controllers sold. I don't fine anyone saying they have a throw away from this model. I'll try to get out to the shop tomorrow and hook my 20a to a 24/100w panel.

Floyd
o$S
JiminDenver
Explorer II
Sep 09, 2013
Rich

You may be the lucky one.
RJsfishin
Explorer
Sep 09, 2013
Ok, sorry I started that thread, but the worst part is I never got that MPPT controller ! This is the first time I ever had any trouble w/ shipment, local or overseas. They want to give me a refund, but I told'm I want what I ordered.
Now they want me to wait another week before they settle. But it seems like I'll never see anything but the refund.
Old___Slow
Explorer
Sep 09, 2013
Nice to read some of the HiTech Posts.

But Hey, I'm the batt boy and not the batter. Hopefully at or near the end of this thread, or the other one running, we will all know 'Exactly what is MPPT?? '(in fact, like science)' If we know the real maybe the fake will also be known?
mena661
Explorer
Sep 09, 2013
pianotuna wrote:
Hi mena,

Here you go:

mppt thread BFL13

Thanks but my post was for others not familiar with the other thread. :)
MEXICOWANDERER
Explorer
Sep 09, 2013
Hey BFL13, "Watts Up?"

Watts POTENTIAL on the incoming versus Watts DELIVERED on the outgoing is the polygraph for maximum potential delivery capability. Another way of looking at it is if the panel has a lot of lead in its pencil and no one to write to despite the need of the battery bank to be charged, then you have a shovel leaner of a controller. This is of course assuming a person knows what they are doing in the wire and connection department, and you do...

Short the panel and read the ultimate potential I available. This will give you are pretty good idea if the panel itself is not shirking. The OCV will verify potential.

Comparisons between potential and actual delivery are the key to determining efficiency. Do a volt drop test throughout the system, from panel to battery. Then multiply by amperage at that point in the circuit.
RoyB
Explorer II
Sep 09, 2013
BFL13 Thanks for update - I am seeing some new ideas to me at any rate. There just may be a way for me to use my three solar panels and get my batteries re-charged back to 90% charge in a short one sun day run... I know you can't make things out something that doesn't exist unless you get to use magic beans or flux capacitors.

Watching both threads with interest...

Roy ken