Solar MPPT or PWM controllers?

B

Billylll

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Which in your opinion is the best controller for a boat? I'm about to do an upgrade on my boat. I'm currently using a PWM controller looking to upgrade the controller to MPPT.
I'm told for battery longevity PWM is superior but MPPT is better for gatting the most amps out of the solar array?
Bill
 
http://www.solar-electric.com/mppt-solar-charge-controllers.html I think that the MPPT controllers might be better on the battery than the PWM controller, as they control the voltage better, but it might be hard to prove either way.

If you're using 12v panels on a 12v battery, the difference may not be that great, but if you are using higher voltage panels, the MPPT controller should be able to adjust itself accordingly. You'll probably find that the bigger, higher voltage panels are less expensive (per watt) than 12v panels.

On small systems the cost of the MPPT controller might not be justified as the controller may cost more than the panels.
 
Morningstar makes both. I'd contact them and ask what they recommend, though with the voltage difference I think they'll suggest an MPPT controller.

Tel: +1 215-321-4457 Fax: +1 215-321-4458
E-mail: inforb2@gr5tmorningstarcorp.com
Website: www.morningstarcorp.com
 
I have a Morningstar 45 amp PWM unit now and have ordered a 60 amp MPPT unit.
I was wondering if anyone had done a comparison?
Bill
 
It's an ego thing. Your not going to outlive either controller and the difference in performance on a normal boat system doesn't amount to squat. Nice thing to talk about when your picking **** with the chickens though. :>)
 
quote:
Originally posted by OLD HOUSEBOATER

It's an ego thing. Your not going to outlive either controller and the difference in performance on a normal boat system doesn't amount to squat. Nice thing to talk about when your picking **** with the chickens though. :>)

Click to expand...

Define normal?
When I purchased my PWM controller MPPT controllers were not available so I have already outlived one controller's technology, what was that comment about anyway OHB?
Did you have something constructive to add to the conversation or did you get up on the wrong side of the bed this morning?
Bill
 
I will be using MPPT and running the panels in series. Not sure which brand of charger I'll be using. Are you running the panels in parallel?
 
A "normal" system is one in which the end needs of the boats usage are served within the panel space available. The simplest controller that will do the job within the confines of the operating systems requirements is the way to go.

Some of the "Geeks" on this forum have the mindset that my specs are better than yours so I WIN.

I did wake up with a headache.
 
I have 3 24vdc panels in parallel, one is 200 watts at 24VDC and the newest what I'm replacing were (2) 130 watt panels with 200 watts each at 24VDC.
OHB give it a rest or keep it up................
Bill
 
Dan what size panels and how many feeding a 12 or 24VDC battery bank?
Bill
 
I am still contemplating. I am thinking no more than 3 200+ watt panels into 2 8D AGMs. I may expand the bank to 3. This year I installed the LinkPRO monitor so I will have a better idea of our usage. As the Summer goes forward I will do some experiments in an attempt to refine my estimates. However, since all of the refrigeration is shut down, it will be empty when I fire them up. I will let them stabilize at temperature but being empty is not representative of the real world.
 
Similar set up here Dan, (3) 8D Lifelines. Think you can not exceed certain input voltages to charge a 12VDC battery system. Since my panels are all 24VDC they will probably stay in parallel.
The voltage output of the panels fluctuate with heat (goes down).
Bill
 
quote:
Originally posted by OLD HOUSEBOATER

You already knew the answer before you wrote the question. So why the post?

Click to expand...

Go find someone to play with OHB.
What are you even talking about, what I read today from Willies post/ link?
Bill
 
Bill Outback Flexmax 60 does not seem to list an limitations. The only limit is a max voltage of 150 and it has auto shutdown. I believe Schneider has a 60a charger that has similar capabilities. Looking at Morning Star nothing jumped out at me.
I am hoping to use a configuration like this to keep the solar side wires to a minimum gauge since they will be the longest. Before I make a purchase I'll discuss it with the techs at the charger shops.
 
Something I've observed with charge controllers is they're rated in amps OUTPUT to the batteries. A 60 amp controller would give you 720 watts at 12v, but 1440 watts at 24v, for the same price. So it might make sense to reconfigure the batteries to 24 or even 48 volts. The whole system would be more efficient. BUT Yeah I know this brings up a whole host of problems...

Inverter... You'd probably have to upgrade to a 24v or 48v inverter. No small change but if you're thinking of upgrading anyway...

How to run all those 12v gizmos (not to mention the engine): That would require a smaller battery bank configured to 12v, maybe a single 8D or a couple golf batteries. Charge 'em with another MPPT controller off the main battery bank. WHEN I get around to upgrading my system this is probably what I'll do:

My "proposed" system (for MY boat): Probably 8-240w panels for about 2kw configured for 48-100v. A 48v, 60 amp MPPT charge controller (2880w, capacity for up to 4 more panels). 8 golf batteries in series for 48v (I like golf batteries). A 48v, 3000w inverter/charger for AC (with any luck it'll run the airconditioner, too). For 12v service I'd have two more golf batteries or an 8D for 12v service and emergency starting, charged off the main 48v bank with another MPPT controller (yes you can use an mppt controller to step down a higher voltage).

Anyway that's the "plan". Once the current battery bank croaks I'll get serious about it.

Will it work for you? I have no idea.
 
Our house is a 12V system. It shares the 12V bank with the inverter. So, we are stuck with a 12V system. If I had room I would install a separate bank for the house and the inverter. But this boat is almost 30 years old and I really do NOT want to pull all of that cable around. That would be very expensive.
 
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