question

steve-coward avatar image

Is the MPPT 200/100 VE.can adequate for handling these 4 LG 360W Neon2 Panels to a 12.8v 600AH LifeP04 battery bank

Looking for advice on the system I'm putting together for my houseboat. Hoping it's ok to run all 4 of these panels off the one Victron MPPT 200/100. Also looking for advice on the overall system and what cables I'd need for each section. Recommendations and concerns welcome. I'm new to this which is why I'm asking and trying to avert a huge mistake.

Including a snap of a Visio drawing and a PDF with links to all the devices below:

LL Solar System Final.pdf


-Victron MPPT 200/100 Specs

-LG Neon2 360W Panels x 4 panels

- Ampere Time 12.v 300AH LifeP04 x 2

-Ampinvt 3000w Low Frequency Pure Sine Inverter w/ 60a charger

screen-shot-2021-05-10-at-114750-am.png

Thanks for any advice and feedback in advance!

MPPT ControllersMultiPlus Quattro Inverter Chargersolar sizing
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1 Answer
Ulrich avatar image
Ulrich answered ·

Do you know the Victron Energy MPPT calculator?

https://www.victronenergy.com/mppt-calculator

Here you can specify whether the modules are connected in series or in series (or both), which voltages and currents they supply. When all the data has been entered, the appropriate MPPT solar charge controller will be suggested. So you can't go wrong.

Cables should always be as short as possible and as thick as possible. And a plus cable always has to be just as long as the matching minus cable. If several batteries are used in parallel, the cables of all batteries must have the same length so that all batteries receive the same voltage.

There is a cable configurator on the Internet and also from Vicotron Energy that specifies these values.

I would take everything from one manufacturer. The Victron Energy MPPT solar charge controller can get data from the Victron Energy SmartShunt via Bluetooth so that it always delivers the correct voltage and current. A Victron Energy inverter can also receive this data so that it switches off in good time if the battery no longer has sufficient capacity.

Was there a few questions I was able to answer? If you have any questions, I'll try to answer them.

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Thanks Ulrich, I appreciate your advice. I have used the vicotron mppt calculator but I'm honestly not a 100% sure I'm entering the info correctly, I was hoping someone more experienced might confirm that these 4 panels can be hooked up to work with my battery bank with an appropriate Victron MPPT charger. I wasn't even sure if these panels are compatible with these 12.8v LIFEP04 batteries. I've bought the inverter and batteries already, just need to match it with the most powerful panels that are compatible with the battery bank to maximize the limited space on the houseboat for panels. Thanks again for your help Sir!

The solar panels must be identical. The resulting voltage must be greater than the voltage of the battery. The MPPT solar charge controller converts the voltage of the solar panels into the charge voltage for the battery. The solar charge controller can be used to set which type of battery is connected.

Example:
Battery: maximum charge voltage 14.4V
Solar panel: (example) 12V 5A (60Watt)
2x solar panels in series: 24V 5A - fits
2x solar panels in parallel: 12V 10A - too low voltage

The numbers of an MPPT solar charge controller mean:
MPPT 100/50
100: maximum 100V on the input side
50: maximum 50A on the output side

If the solar panels are (theoretically) delivering 120W, at 14.4V that's about 14A.

In your case:
4x 360W = 1440W (theoretically maximum)
1440W / 14.4V = 100A charging current

LG Neo2 41.6V
2x parallel + 2x serial = 83.2V 20.56A
(be careful not to touch the cables, you will be seriously injured)
Make sure that the cables are short and strong enough.

Thanks so much Ulrich, that's great news, looks like I've got about as much potential power as I can possibly jam into this small amount of space.

I'm wondering if you have any suggestions on where to get good cabling and what short means in this case. The panels are probably up to 15', maybe 20' from the charge controller. And then will be around 20' from there to the battery. Do you think that distance is an issue? I don't mind dropping some money on good solid high performing cable that will Max efficiency and be very safe. What would you recommend for these distances?

Thanks again for the help, I feel better buying the panels and charger now that you confirmed it's all compatible.

Sure, cables can only be as short as they need to be long. :-)

Do you mean by 20 feet? That is about 6 meters.

An example:
13.5V - 100A current flow - 6m cable length

20sqmm cross-section
7.93% (1.07V) loss = 12.43V on the battery: not OK

40sqmm cross-section
3.39% (0.53V) loss = 12.97V on the battery: OK

With 100A charging power distributed over two batteries, that's still 50A per battery. A charging power of 200A is specified for your batteries. If you charge them with 50A, then they will live significantly longer. A LiFePO4 can also age very quickly if you treat it incorrectly.

The supply line from the solar panels is not that critical, 4 square mm is sufficient here, 6 square mm is of course better. The thicker, the less loss.