Solar help... Mppt or PWM

lawrosa, I know what this controller can do - and, more important, what it can't :)... We've been there before.

You can't compare a generator or alternator charging to solar - they are meant for different scenarios. I'll just note that a regular 7-pin connector from truck and a full charge don't go together well.

Well here is a quick pic of what I got..

Its a pretty good unit IMO for $110 bucks.. It does what it says..



Enter system voltage...




I got 16.11 amps fron an 37 volt 8.7 amp panel.. Not bad.. I had evetything running I could in the camper...

Stove fan, vent fan, every light( All LED), a 100 watt box fan, and the heater fan.. It was hard to kill the batterys.. Battery voltage was showing 12.1 volts with everything running...




Standing in front of panel amps way down...



I set the bulk charge at 14.8volts on this controller.. After it went out of bulk and into float @ 13.6 volts it showed about 3 amps...

So I increased the float to 14.5 volts for float and the amps increased to about 10 amps. I left it there until the amps went down to 3 amps again then change the float back to 13.6.. The unit then went into sleep mode..

I am going to use this as a portable.. I have about 50 ft of 8 gauge and will add a 8 gauge trolling motor plug from the MPPT and mount to front of camper.. I ordered both ends. This will let me plug in the panel and put the panel in the sun..

Trolling motor plug

I also ordered this leg kit.. Its worth it as my machinist buddy said he cant make it cheaper..

Solar tilt kit..

So Free panel
Free 8 gauge wire
$110 MPPT
$50 Tilt kit.
$30 8 gauge connector trolling motor
$10 8 gauge pin connectors..

Im into this for about $200 bucks...

Is it worth it? IDK.. I was happy with my truck alternator charging my batts for the weekend..


Here is my alt charging mod.. I thought I had a post on here about it.. I am a super mod in the DIY sites..

Seems mods here may be deleting my posts.. I dont know..

Charging rv batts from tow vehicle alternator...

Leafy shade is one reason I used series panels with bypass diodes and MPPT. My 3 series panels with 3 bypass diodes each are in effect 9 panel sections. If 2 or more sections have sun the battery is charging. PWM requires an entire panel to be in the sun.

I'm not suggesting that this is a huge overriding factor but it was basically a freebie for me along with other considerations.

So I'd get some charging throughout the day in the above photo.

For wire size reduction search on compression reducing splice or step down butt connector, insulated etc. These provide a much "cleaner" install vs the above Amazon connectors.

Perhaps someone has a good source.

Thanks,

Sounds as if that is a variant on poly.

Don, it's a "multicrystalline" ;) Trina 255W.
One of their better in-house brands. Still, Chinglish.

Mono or poly, it won't do much where the trailer is parked on the photo.

Mono or poly panel?

lawrosa wrote:

How in the world do you connect 6 or 8 gauge wire to that tiny connector..

Got what you paid for, I guess. Though controllers under 30A often have terminals #8.

Use butt splicer. Or splicer-reducer, wrap it into insulating tape. You only need #6 (or thicker) to the battery.

lawrosa wrote:

Not sure what size terminal will fit..

If this controller is anything like others in the industry, you don't need any "terminal" or those lugs in your link. Loosen the terminal screw on controller, put the stripped end of cable in, tighten the screw.

Well I got 8 gauge pin connectors.. They should work fine..

Had it hooked up as a test today. I turned everything on in the camper I could.. I was netting 16 amps.. Not too bad..That was 14.8v bulk setting

When it went into float The amps went down to 2 or so. So I adjusted the volts in float from 13.6 to 14.5v which is the highest it goes.. The amps jacked up to 10amps.. I let it sit there until the amps reached about 3 amps then put it back to 13.6. The mppt then went in sleep mode and batts showed 13.8 volts..

I should of ran a load to see where they where at after surface charge removed..

Now Putting my body infront of the solar the amps drop to nothing.. So I am rethinking putting this panel on the roof..

I dont have any boondocking spots here on east coast that does not have trees..

Like the spot I show here I would have to move the panel around..

Well got the controller.. Now an issue already..

How in the world do you connect 6 or 8 gauge wire to that tiny connector..

Looks like 6 gauge does not fit unless I split the strands and slide the wire on both sides of the screw..

Not sure what size terminal will fit..

Like a #8 stud? I cant find no such animal for 6 gauge.. Only think maybe a flat pin connector I see..

Best I could find is #10 screw here for 8 and 6 gauge...


http://www.amazon.com/Ancor-252245-Marine-Electrical-6-Gauge/dp/B000NI1FQC/ref=sr_1_3?ie=UTF8&qid=1460316141&sr=8-3&keywords=6+gauge+wire+connectors