Adding 80W AKT Solar Panel & 10A charge controller to national luna split charge sys.

[JimmiSashimi]

Hello Hubbsters,

I am about to get an 80W AKT Solar Panel Kit with 10A charge controller for my defender 110, 300 tdi before leaving for Africa in Jan. 1 year over land.

Can any one recommend best set up to add the solar panel into the national luna split charge system that is already installed?

I am hoping I can simply add the solar power feed from the solar 10a charge controller directly to the main battery terminals (as a standard recommended AKT installation). Is the theory sound that when the engine is off then the solar charge controller will do its job BUT when engine is running the national luna split charge system will kick in and the solar charge controller should hopefully turn off by sensing higher voltage (i.e. sensing the battery is "fully charged" - despite the voltage that is turning off the solar charge controller would actually come from the alternator)?

This way the 80w solar system would infect keep both batteries at close to full capacity and split charge solenoid would do its "5 minute on after main battery receives charge" cycle.

Any thoughts before I cause damage?

Perhaps Plan B would be to wire the solar charge directly to secondary battery (including the 10A solar charge controller)?

FYI - System is 2 x PC1500 Odyssey batteris (AGM).

Many thanks,
JS

[Surfy]

I plan near the same.

I have the national luna PPP. It has too the national luna split charging system.

And I Plan to add a 112W Solarpanel (brand dont matter).

The guy who will install it (a solar company) means, that he will connect the solarcharger directly to the Battery (who is inside of the national luna ppp).

If it is an MPPT charger it will help to deliver an UIUI Powerline to the battery, in addition to the power who comes from the alternator after 5 min.

I`m not a technican, I will try it out this way - and hope the the guy know what he do.

Hopefully here is someone who can approve that this is a good way to do that job. If you have time, in a month I will know if it works that way..

Surfy

[steve/m]

Hi Jimmi
I have exactly the same system set up you are suggesting and have used it for 5 or more years but I have the solar feed only charging the leisure battery, make sure that you use at least 4sq/mm cable to get around the voltage drop on the long length of cable Steve/m

[Overland Tonka]

I have an 80w solar set and a spilt charge relay between the starter batt and leisure batt...the solar panel is wired directly to each batt (via the controller) and i select the amount of charge to each batt from the controller 50/50 80/20 etc etc as required.

Everything works great...no need to worry. Stick it on and enjoy.

[bobn]

Hi Surfy,

As I have found many of your posts usefull to me, I thought you may benefit from a little advice.

1) I would not concider anything other than an mppt charger
2) Solar panel must always be connected with correct cable
Polar Wire Products Prebuilt Solar Panel Interconnection Cables
3) Unless you just want to recharge your phone,112W is nowhere near enough power and don't think that 112w panel will give you 112w, more like 25w. 112w quote acheivable under lab conditions only.
4) DO NOT waste your money on cheap chinese brands. They are VERY inefficient and fragile so will not last long on a vehicle. Also, make sure the output voltage of the panel can be input on to the solar controller without exceeding the max controller voltage input. My panel is bolted flat to the roof rack Sanyo panel (read up on flat mountedt efficiency)
Bought from these people ( import for me, just down the road for you) Panasonic / Sanyo 240W HIT PV Panel

Solar Charger (Note the open circuit voltage rating of 75v)
http://www.off-grid-europe.com/soltr...rge-controller

[Surfy]

Originally Posted by bobn

Hi Surfy,

As I have found many of your posts usefull to me, I thought you may benefit from a little advice.

Thank you much for your suggestions and advice!

I plan to buy some pretty powerful panels with 22% efficency. Solbian SP line (one with 112w the other with 100w, flexible).

I did ask severall longterm travellers. 200w seems to be enough by good weather - more is better for a rainy week with less sun.

My AGM Battery did ask for 14.8 volt - what seems to limit the possible MMTP devices.

I did find two of them, who can deliver that ammount:

- Votronic SR 330 Duo Dig
- Western WRM-15 MPPT

Thanks to for pointing to the cables and so. Are these 4mm2 cables thick enough? I plan to mount the 100w on the hood. That needs around 5m length to the MMTP charger.

The 125w Panel I will fit when I am stationery on a safe place at the roof box.

Maybe you can help me to avoid some bigger mistakes who can cause problems during our journey Or to spend the bucks on the wrong place.

Surfy

[Overland Tonka]

Our 80w Bosch set up manages to keep our starter batt nicely topped up and the leisure batt in good health as it runs our fridge and other charging items.

I did the usual calculations prior to our purchase and have monitored the batts as we travel...all has been perfect with our 80w set up.

Just saying that this works for us and i don't want to get into a "Mines bigger than yours" discussion...

Also read up about weather variations.....it can be too sunny for some panels you know.

[Surfy]

@Overland Tonka: the question is, how much power you need daily. And how long you plan to stay at a place without to use your engine and local power sources in campsites.

I carry two engel 15l cooling boxes. One is used as freezer, one as a normal cooling box. Then a Notebook, Camera, Smartphone, Tablet, Satellite Tracker and so on...

And I avoid campsites, I loves to wild camp - so there is no 110v/220v line.

On cloudy conditions I guess I will need these Solarpower.

Surfy

[Overland Tonka]

We have no mains power hook up and only use the solar panel. As you say its all down to how much you may use. All our lighting is LED. My main concern is making sure the starter batt is always ok...

I keep a check on the batts and may turn something off when using something else...or ensure all my charging is done at the right time of the day. We run a 40ltr engel fridge...and if the Mrs is using the clippers to cut my hair via the inverter then we switch the fridge off..it's only for 30mins. After all..i'm living in a car not a house.

[Griffdowg]

Im working on the same as Tonka.

You can get 3 days out of a 2nd battery running a 40L fridge, an 80w panel will help push us to 4.5-5.5 days.

Were a bit limited on space and the portable 120w was just too big. 80w works for size and 5 days without starting the engine is plenty of time in the bush!

G