Affordable Charge Controller for AGM Battery

[Amy@altE]

You're very grounded, from what I have seen. Be-dum-dum

That's because I meditate. Ohm.....

[jony101]

For the low voltage panels like a 100 watt panel. expensive MPPT is not going to be efficient. I also heard about MPPT not being efficient with the smaller panels but i had to try it for myself.

As an example I had a 120 watt kyocera panel (max voltage i saw was about 21 volts) , I tried it with both a 20 amp pwm wincong controller (20 dollar) and a 20 amp mppt ecoworthy controller (102 dollars), hooked up to my giant 145 ah agm battery.
with mppt I get about 6 amps
with pwm I get about 7 amps

On the other hand with a larger 240 watt sharp panel (max voltage i see is 36 volts) and same battery.
with mppt i get 12 amps
with pwm i get 7 amps

You can get a cheap 10 amp wincong controller, they were extremely reliable for me for the low price. Just make sure you get a 90 volt 30 amp LED combo meter and connect between you controller and battery so you know exactly how much amps/voltage is going into your battery instead of relying on blinking lights. The wincong works great on agm batteries, thats the only batteries I use.

Only get an mppt is you plan on buying another 100 watt panel, connecting 2 x 100 panels together in series will get you the over 30 volts of electricity that the mppt needs.

[Sunking]

As an example I had a 120 watt kyocera panel (max voltage i saw was about 21 volts) , I tried it with both a 20 amp pwm wincong controller (20 dollar) and a 20 amp mppt ecoworthy controller (102 dollars), hooked up to my giant 145 ah agm battery.
with mppt I get about 6 amps
with pwm I get about 7 amps

On the other hand with a larger 240 watt sharp panel (max voltage i see is 36 volts) and same battery.
with mppt i get 12 amps
with pwm i get 7 amps

You need to get a real MPPT controler and try again. You got robbed buying an Ecoworthy controller. Any true MPPT controller Output Current = Panel Wattage / Battery voltage.

Here is your proof. With any PWM controller Input Current = Output Current. A 120 watt Kyocera panel Imp = 7 amps. If it were a real MPPT controller with their claimed 96% conversion efficiency would be [120 watts x .96] / 12 volts = 9.6 amps. Your 240 watt panel should be pumping 17 to 18 amps.

Rather you want to admit it or not, you got screwed.

[photolimo]

Here is an interesting project from an EE in India. His first attempt is a PWM but version 3 is MPPT. What really caught my eye is that it has an integrated Ah/Wh meter.

http://www.instructables.com/id/ARDUINO-SOLAR-CHARGE-CONTROLLER-PWM/

http://www.instructables.com/id/ARDUINO-SOLAR-CHARGE-CONTROLLER-Version-20/

http://www.instructables.com/id/ARDUINO-SOLAR-CHARGE-CONTROLLER-Version-30/

What do you all think of his work? I wonder how one could improve on its design?

[SunEagle]

Here is an interesting project from an EE in India. His first attempt is a PWM but version 3 is MPPT. What really caught my eye is that it has an integrated Ah/Wh meter.


What do you all think of his work? I wonder how one could improve on its design?

Last year there was someone on the Forum that was building a home in Alaska or North-West US that was also dabbling in an MPPT equipment design. He may have even gone the route of using Kick-start to help fund his design. I haven't seen any new info on it.

I am sure there are many table-top scientists/engineers working on a "new" equipment. But like anything new it will be an uphill battle to get their device to market if the big guys put any roadblocks in the way.

[Sunking]

Last year there was someone on the Forum that was building a home in Alaska or North-West US that was also dabbling in an MPPT equipment design. He may have even gone the route of using Kick-start to help fund his design. I haven't seen any new info on it.

That moron was Electrocudas. He has been ran off all solar forums. He showed up on Mike Holt's site and got Bar-B-Qued and banned in a day. He also showed up on a DIY EV Forum, lasted 3 days with 200 pages of blather from him and got roasted before they pulled the plug. The guy is an excellent Troll, I have to give him that. But on Mike Holt and the EV forum is full of jerk engineers like me who blasted him. Poor guy does not even know Ohm's Law or basic formulas any first year student would know. Pretty comical.

[bcroe]

Here is an interesting project from an EE in India. His first attempt is a PWM but version 3 is MPPT. What really caught my eye is that it has an integrated Ah/Wh meter.

http://www.instructables.com/id/ARDUINO-SOLAR-CHARGE-CONTROLLER-PWM/

http://www.instructables.com/id/ARDUINO-SOLAR-CHARGE-CONTROLLER-Version-20/

http://www.instructables.com/id/ARDUINO-SOLAR-CHARGE-CONTROLLER-Version-30/

What do you all think of his work? I wonder how one could improve on its design?

I don't see a coil on that drawing; there need to be some reactive elements in a buck.
I don't know about his software, but that breadboard reminds me of something I had to
help high school students with. Their 8080 didn't work, because of inductance in the
reference network (ground). Switching circuits need a very low inductance ground
plane reference (unless totally differential), and it just gets worse as the power level
goes up. Bruce Roe

[photolimo]

That moron was Electrocudas. He has been ran off all solar forums. He showed up on Mike Holt's site and got Bar-B-Qued and banned in a day. He also showed up on a DIY EV Forum, lasted 3 days with 200 pages of blather from him and got roasted before they pulled the plug. The guy is an excellent Troll, I have to give him that. But on Mike Holt and the EV forum is full of jerk engineers like me who blasted him. Poor guy does not even know Ohm's Law or basic formulas any first year student would know. Pretty comical.

I would be nice if you had something positive or constrictive to add to this discussion.

[photolimo]

I don't see a coil on that drawing; there need to be some reactive elements in a buck.

There is a coil here that he hand built:
F30MIRPI6C2OB20.LARGE.jpg

[bcroe]

There is a coil here that he hand built:

OK then he's on the right track. I didn't click all the right places. Can't see his wiring,
but with that scope (better than I had in the 60s) he should eventually figure out the
issues with parasitic elements. My switchers look like a copper box surrounding the
elements.

Those toroid cores get pretty expensive at power levels. Bruce Roe

[Sunking]

I would be nice if you had something positive or constrictive to add to this discussion.

OK his terminals and wiring suggest a toy or no real use. There is nothing to invent, LSI circuits already exist to do this and much more.

[mrturner]

hey guys new to this.if I wanted to charge a 130a/h agm with a 200w panel with max voltage of18.3 v what would be the perfect controller to use.

[Mike90250]

hey guys new to this.if I wanted to charge a 130a/h agm with a 200w panel with max voltage of 18.3 v what would be the perfect controller to use.

Are you wanting a voltage of 18.3 at the battery or is that the VMP voltage of the PV panel ?

[mrturner]

Hi that was the voltage quoted on spec sheet of panel

[Mike90250]

OK, so that's about 12 amps the controller needs to handle.

here's 2 name brand models:
Morningstar SL 20L 12V $105
or
Morningstar SK-12 SunKeeper 12 Amp PWM $85