panel recommendations please

also looking here - low energy solar panel.

Hi Sleeprequired
'
many have purchased from the same ebay site though 140W folding. i am extremely happy with it. I didn't expect it to work to the specifications that were quoted though my panel has exceeded the max amps quoted. Must say i have only had my panel for 2 months and it has not been left out. Packed up after each camping weekend.

I have purchased many panels of various types from Low Energy Developments and have been happy with both their service and product.

Regarding MPPT charge controllers, most of the inexpensive units are not MPPT even if they say they are (especially the cheap Chinese ones). Often they simply hold the array's minimum voltage at a fixed level (say 13V) rather than allowing the battery to drag it down too far. It's probably better than nothing, but it's not true MPPT and it won't be as effective as "real" MPPT.

Running multiple controllers to one battery is OK (if this is what you intend) as they will each decide when to drop to float depending on the settings of each unit, but do make sure that the battery can handle the combined maximum charging current! For example a 100Ah AGM battery may have a maximum charge rate of perhaps 30Amps, which is 405W at 13.5V or 345W at 11.5V.

I don't know what you are going to use this panel for, but a 200W panel is physically quite large. If you're going to use it freestanding make sure it doesn't blow away!!

ok so i currently have

ok so i currently have this 130w folding panel, along with the controller that came with it.

I also have a 120ah ritar battery.

What i am going to do is add another battery and a 200w solar panel.

so this panel 12 v 200w panel, with this contoller here - MPP PCM-3012

it says 300w max but i'm thinking the 330w total will be ok given real world limitations.

Comments? What is the difference between 12v panel and 24v panel? Is this the right setup? how do i run both panels into the controller? At the moment i have 2 x anderson plugs going to the battery, and the crappy controller is connected to the portable panels.

do i just run both anderson plugs combined into the controller, then to the battery?

Hi Sleeprequired,

Just be careful not to run a 12v panel and 24v panel together, or put them through the same controller. Either run two 24v panels and set the controller for 24v or two 12v panels with the controller set to 12v.
Are you going to run the 2 batteries in series or parallel? I would recommend you set them up in series as most things you have will be 12v and you will get max. benefit out of your batteries. I would also run one good quality controller and have your two Anderson plugs out from the controller. Stick with all 12v. Good luck.

Dereelgirl

Ok I believe my existing panel is 12v so ill buy another 12v Panel. Then run Anderson's back to the controller where they will join where they are inserted into the controller which is then connected to the battery.

I was shooting for basically one big 240ah battery.. Is that hooking them up in series or parallel? If I hook them up in parallel does it become 24v

Can you explain what you mean and how it would be getting the most out of my batteries to have then hooked up in series instead of parallel

If I hook them up in series aren't I doubling the voltage instead of the amp hours? Why would that be best. ?

I. An earlier post above I asked about the Mppt PCM-3012 being able to handle both this 130w folding panel and this 200w panel from rich solar.

Can someone take a look at the specs of the controller and panels and tell me which amp and volt measurements on the panels apply to which specs on the controller?

I think I'm pretty spot on with the amps - 18, however I'm not sure if I'm correct with the volts???

ok i need some help here...

the solar controller i'm getting is in the above post - it's the pcm-3012. The guy selling it to me is telling me to hook my panels up in series rather than parallel...

1. because the current is bordering on 18a which is too much
2. and because the voltage of the 130w panel is rated at 16.88

He is saying that in low light conditions that the 16.88v MPV may fall below the solar controllers 15v lower limit, thus rendering the MPPT useless and hardly charging anything.

so should i series them and get the combined voltage of 16.88+18.7?
does this halve the amps?
will the MPPT then convert the extra voltage to amps?

He thinks i will get about 260w if i series them which is close to the 300w limit anyway..

So i'll be adding the voltage and halving the amps but then the MPPT will convert the additional voltage to amps correct?

so how many amp hours can i expect from 260w in series pushing say 33-36V?