My solar upgrade thread

Howdy folks,

I have a 20 watt mono and an 80 watt polycrystaline panel wired in parallel to a Morningstar Sunsaver 10. I've measured it at just over 6 amps in the past.

I am using this panel to charge a Diehard Platinum 31M auxiliary battery and a Diehard Platinum starting battery through a PowerStream solid state isolator. The alternator is also connected and charges both batteries through the isolator. I am powering a Norcold NRF-45 fridge with a custom thermal blanket. The stereo draws from the aux battery as well but I try to limit my use when the vehicle isn't running.

I've decided to add a second 100 watt panel to the roof to give me more headroom on long trips. The Solar Synergy 100 watt panel has a max current of 5.8A.

This would oversubscribe the Morningstar Sunsaver 10 by an amp or two at peak output. Can the Sunsaver handle it or do I need to upgrade this as well?
 

unseenone

Explorer
I wouldn't swear to it, but I believe the excess is clipped. This makes sense, as you rarely get the rated capacity anyway. If it turns out to be problematic you can always eliminate the 20W panel.

I'm not a fan of the sunsaver, but for no other reason than they seem fairly bare bones. It can never hurt to have extra capacity, and you can probably sell the old in the for sale section one if you decide to upgrade.
 
What are you in favor of?

I don't want to damage it experimenting, or worse, have it fail part-way through an upcoming trip. How would it clip the amperage? I imagine a fuse or something would blow, or a shunt would burn up, but I'm no expert on these things. I'm a bit confused about what the 10 amp rating really means and how it translates to watts. Is that 10 amps @ 12v? 14v? Panel voltage (closer to 18-20v)?

I could add a second Sunsaver 10 for ~$50, buy a 20 for ~$100 and sell my old 10, or something else?
 

unseenone

Explorer
shoot, just lost my post.
.
I read the manual, the Sunsaver has a solar overload circuit. It could be a hassle if you trip it and have to reset it to clear the fault. Simplest, is you can add another 10 and run them together, the next option would be to upgrade to the 20. For my money, I'd be more inclined to do a Prostar 30M which will give you some growth potential. It also has a meter, which shows voltage, Charge Amperage, and load amps. Kind of neat to see what it's doing. Here's a picture of it in action.

Just fiddling around with calculations compared to real world on various units. Watts / Volts = Amps. Generally speaking. You can get a lot more technical about it, so if you are putting potentially 200 Watts it could generate approx 15-16 Amps.
 
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The Prostar does look cool. and I like gauges and meters but the 30 is pricey for this project, especially considering my roof is about to be full of panels. It's not too likely that I'll go over 200 watts. The Prostar 15, however, is as cheap as $85 on Amazon. I could consider that route.

But as for load and capacity ... I'm still a bit confused on how these things are rated.

Going by Ohms law, if my panels are putting out 18v, then 200 watts can push out 11amps on the solar side of the controller. On the other hand, if the battery charge controller is at 14v, then 200 watts yields 14.2 amps on the load side. If I go by the "maximum power current" ratings on the back of the panels, the 200 watts of panels would come out to 11.65 amps.
 

wrcsixeight

Adventurer
I have a 130 watt Kyocera panel in parallel with a uniusolar pvl 68 and a Bluesky 2512i MPPt charge controller along with the IPN pro remote battery monitor.

My wiring from panel to controller is thicker than it needs to be.

I'll see a maximum on june 21, panels flat on my roof of about 12 amps in and 13.5 amps out with the MPPT conversion. There are edge of cloud events where I have seen this double, briefly.

The DHP31 is an excellent battery, yet is is a bit of a recharge amp whore. Odyssey recommends a minimum 40% recharge rate until 14.7v is reached. 14.7 is then to be held for 4 hours as the amps required to hold 14.7v taper.

So that group 31 wants 40 amps bulk current when cycled deeply.

Perhaps your alternator can meet this, your solar never will. The dhp31 will perform better and last longer the more often you can recharge it at the 40% rate.

Don't trust the blinking green light. It lies.
 
My plan right now is to pick up another Sunsaver 10 and a 100 watt solar cynergy panel. I'll send 100 watts to each of the Sun Savers, so I'll have 2 solar "banks". This has the advantage of being cheap and it allows me to charge two battery banks independently or run them in parallel to charge my underhood batteries.

I understand the Prostar is better than the Sunsaver but I don't see what it does differently that I really need. Right now it feels like over-engineering.
 

4x4junkie

Explorer
But as for load and capacity ... I'm still a bit confused on how these things are rated.

Going by Ohms law, if my panels are putting out 18v, then 200 watts can push out 11amps on the solar side of the controller. On the other hand, if the battery charge controller is at 14v, then 200 watts yields 14.2 amps on the load side. If I go by the "maximum power current" ratings on the back of the panels, the 200 watts of panels would come out to 11.65 amps.

With a standard PWM controller such as your SunSaver or the ProStar, power from the panel(s) is simply routed straight through the controller to your battery. This causes the panel(s) to operate at your battery's voltage rather than at the panel's Vmp rating, so the maximum current you will see going into your battery will be something that is between that of your panel's Imp and Isc ratings.

As you might expect, this means a 100W panel having a 17.5 Vmp effectively produces about 70-80 watts or so. To harvest the full rating of the panel, you would need a MPPT (max power point tracking) controller. MPPT controllers are usually about 2-3× the cost of a standard PWM unit, so in a lot of cases it's more cost-effective to up-size your panel(s) rather than buy a MPPT controller if you need to have that last little bit of power.
 
That is helpful. The math is a bit loosey-goosey, but from what I can tell, a 10-amp PWM controller can handle ~150 watts (rated) from solar panels. I would definitely be over-subscribing my controller. Whether it could handle that or not is another question, but to be safe, it's time for an upgrade.

Solar Boulevard's MPPT controllers are too pricey for my purposes but I see on Amazon that I could get a 20amp Tracer 2210RN for about $120.

At that price range it starts to get interesting.

* For $175 I can add a 100 watt panel & 10amp Sunsaver PWM controller, which combined with my existing panels & controller would yield around 160 watts of usable solar power.
* For $245 I can add a 100 watt panel & 20amp Tracer MPPT controller, which combined with my existing panel would yield much closer to 200 watts of usable solar power. I could then recoup some costs by selling off my old Sunsaver 10.

Is it worth it? I think so, provided that a cheaper MPPT controller like the Tracer is a quality piece of kit. I'm really not sure how to evaluate that.
 
I see there is also an Instapark® MPPT-2010 12V/24V, said to be a rebranded Steca controller, for only $87. Perhaps an MPPT upgrade is the right way, though I don't know where I'd find the space to mount one of these. It doesn't look like it could handle being in the engine compartment and it's a bit chunky to fit inside the cabin. Hmmmm...
 

4x4junkie

Explorer
The SunSaver MPPT is the one I use also. I chose the MPPT route mainly because mine is a portable setup, I wanted the most power I can get from two 85W panels without it being too big & heavy (which also allows wiring the panels in series for lower current so that I can use a lighter gauge wire between the panels and the controller).

For hard-mounted panels, PWM w/parallel-wired panels usually provides more value.

I agree about sticking with the better-known brands when it comes to MPPT controllers... In the past I had found a crapload of cheap chinese PWM units out there that were actually masquerading as "MPPT" units.
 
The MorningStar MPPT is way outta my price range, especially considering the solar panels are not critical. That said, I hear you when it comes to quality components.

The rebranded Steca MPPT controller may be a great value but I don't know much about any of the manufacturers. Not sure which way I'm going to go yet.
 

unseenone

Explorer
Morningstar makes a fine line of PWM controllers, in all price ranges...

I'm just saying, we also should try to support American companies, especially when they have a decent product. Outside of the US, people do like American made products for a good reason, foreign governments import regulations are most likely the biggest culprit.

What's your budget?
 
Yes but I'm considering an MPPT controller, and that's not going to come from MorningStar.

If I go with a PWM controller, I'll get another SunSaver 10. It's affordable and I've had good experience.

Budget is $200 for panels & any controller upgrades.
 

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