Solar on our Motorhome Van, but not sure which controller to get ? help please

[Rixsta]

Basicly my panels with multimeter show around 47v each max not the 36v on the label.

[SunEagle]

Cheers
It's all starting to make sense a little.
For a while I was very confused with series vs parallel panel wiring, I'd presumed the power you got from wiring in series was less that parallel due to lower ampage.. But then I realised the watts in both setup are still the same? Otherwise we'd all be wiring in parallel!

Your post is very helpful

My panels in series = about 140 to 145v max in bright English sun. Morningstar MPPT 60A max voltage is 150v.
I never saw my panels go over 47 each would you say it's within safe region? Ok to use

Just remember that a panel can exceed its' Voc rating during the very early morning sun in cold weather. That is why the charge controller mfg tell you to add up the Voc for the series wired panels and add a % fudge factor to see if the total does not exceed the DC volt input rating of the CC.

[Wy_White_Wolf]

That's great being able to Check the batteries, yes I'll have a laptop to view it all.
Do you know where best to buy the morningstar in England? Best price.. Or if anyone knows of website that sells second hand?

Also one more question

Ok this is important.. I could save a lot by getting the PWM controller by Morningstar is the MPPT overkill for our van? We will be traveling in it and living so..

Just trying to make sure I do the right thing before spending a lot of money.

Using a PWM controller would cut that 660 watts down to about 210 to the batteries. Do you really want to throw 2/3 of your solar away.

As far as spending a lot of money you should have researched a little further before buying the panels. They are mismatched for your need without a MPPT controller.

Either get a 60 amp MPPT or get a smaller 20 amp MPPT and only use 1 panel. Your already planning on charging the batteries from the engine alternator so just watch the battery voltage and run the engine if the 1 PV panel can't keep up.

WWW

[Rixsta]

No problem going with MPPT here just wondered if the gains would justify the extra. Yes the panels cane to me cheap £160 for 3X 210w
So happy with that but yes could have researched more lol.

Is voc working voltage or something else? I've not been able to find much info on the panels apart from what's on the label which says working voltage 36v

Cheers I'll stick with the 60A Morningstar . There's one on eBay with meter and temp sensor right now.

[SunEagle]

No problem going with MPPT here just wondered if the gains would justify the extra. Yes the panels cane to me cheap £160 for 3X 210w
So happy with that but yes could have researched more lol.

Is voc working voltage or something else? I've not been able to find much info on the panels apart from what's on the label which says working voltage 36v

Cheers I'll stick with the 60A Morningstar . There's one on eBay with meter and temp sensor right now.

Most panels have the following specs listed on the back of the panel

Watts = Vmp x Imp
Voc = open circuit voltage
Vmp = maximum power voltage
Isc = short circuit current
Imp = max power current

[Rixsta]

Interesting that mine only mention

1580x808x35

210w

36v working voltage

5.83A working current

15.5kgs

[SunEagle]

Interesting that mine only mention

1580x808x35

210w

36v working voltage

5.83A working current

15.5kgs

The "working" voltage is the Vmp and current is Imp. Usually the Voc is at least 6 to 10 volts higher then the Vmp but the panel should have it listed.

[Rixsta]

Ok thanks for that
Im planning to power 400w heater, does this idea seem insane with solar or ?

[SunEagle]

Ok thanks for that
Im planning to power 400w heater, does this idea seem insane with solar or ?

Without trying to be nasty, yes using solar pv to run a heater is insane. There is a major efficiency issue. The amount of solar pv needed to run a heat load like that would end up costing way more than you will even save. Mostly because you will be using more energy then what you get out of that heater. PV works well on some loads but not really those that cool or heat your home.

[Rixsta]

It's ok lol
Because we are not living in a house or even have a house and planning to live in our van conversion we've been looking at alternative or other ways to produce heat along with gas fire etc. The van is a large works van full length it's pretty nice in there now after insulating it.

So yes we're not heating a home and the only electricity we have is from van alternator and solar.

I am aware that it takes a lot if electricity to heat. Ok so scrap that idea then.
I guess I imagined in England I could expect at worse case 2 hours of sun equivalents on the worst days which would equal 2X 660w of power but of corse less than that after wire losses charge controller loss etc.
So perhaps in a day would have at worst case 1 hour of 660w.
Our heater being 400w would be enough to warm our van for an hour on the least sunny days.

I guess I'll just stick to powering the laptop and phone and use gass alone for heat

[Bigmacsc1]

Hi everyone. I just purchased my first solar kit to install on a 32 foot pontoon. I have a single 50watt panel with a 10 amp controller. My question for everyone is can I run two lines from the battery connections. One set to connect to the trolling motor batter on the front of the boat and one set for the starting battery. Running the batteries in parallel won't work because of the distance between the two batteries. Any advice would be greatly appreciated. Also, do I just leave the lights and radio and depth finder connected to the battery or do I need to hook them up the load connection on the controller. Appreciate any help y'all can offer.

[littleharbor]

You still should parallel wire your panels as they are already double your 12 volt bank voltage, which is the sweet spot for efficiency on an MPPT controller. If you are going to use all 3 panels in parallel you will need to fuse each panel. 3 of those panels in series will likely be too much voltage for your controller considering your cool locale.

[SunEagle]

Hi everyone. I just purchased my first solar kit to install on a 32 foot pontoon. I have a single 50watt panel with a 10 amp controller. My question for everyone is can I run two lines from the battery connections. One set to connect to the trolling motor batter on the front of the boat and one set for the starting battery. Running the batteries in parallel won't work because of the distance between the two batteries. Any advice would be greatly appreciated. Also, do I just leave the lights and radio and depth finder connected to the battery or do I need to hook them up the load connection on the controller. Appreciate any help y'all can offer.

I would suggest you get a second panel and charge controller for your starting battery. Running wires to two different batteries from the same charge controller would be a mistake and could cause one or both of those batteries to not fully charge.

[Rixsta]

Ok so update.
We got a very good deal on 4x 12v powersafe batteries. 150ah each

So I now have, and note not planned very well!

660w solar panels highest open voltage read in 2 weeks was 135v
Morningstar MPPT 60a controller
4x 155ah powersafe 12v batteries.

4awg wire from controller to batteries
The last thing to get is circuit breakers or fuses.

Anyone know if circuit breakers will be ok with the system ? Am I looking at DC circuit breakers I guess ?

And batteries will be wired in parallel.

[littleharbor]

Midnite Solar makes inexpensive DC rated circuit breakers. Probably your best bet.