question

hotwaterjoe avatar image
hotwaterjoe asked

Need Help On MPPT Location

Newcomer here.

Here is what I have:

1. 30' trailer that is "pre-wired" for solar. 10ga wire running from roof connection to closet about 15 foot wire run. 8ga wire from closet to battery bay also about 15 foot wire run.

2. Running 2 Zamp 170 watt panels in parallel.

3. Have Victron BlueSmart MPPT 110/30 controller

4. Have Victron BMV-712 with temp sensor.

Question: Which is better:

A. Do I place the controller in the closet and connect to the 8ga to the battery side and the 10ga to the PV side? Use the VE Network to provide battery temp and voltage to the controller.

or

B. Do I splice together the 8ga and the 10 ga, and then place the controller in the battery bay and run short 6ga wire to the battery from the controller.

The issue I am trying to avoid is voltage drop from the panels if I place the controller in the battery bay.

Thanks,

Bill

MPPT Controllers
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3 Answers
Murray van Graan avatar image
Murray van Graan answered ·

Best would be to have the MPPT as close a possible to the batteries Bill

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klim8skeptic avatar image
klim8skeptic answered ·

Hi bill,

"The issue I am trying to avoid is voltage drop from the panels if I place the controller in the battery bay."

The bigger problem would be the voltage drop between the controller and battery (about 0.6v). Networking the mppt and bmv for temp/volt charge compensation might work......

I would move the controller close to the batts, and wire the panels in series (if practical).

https://www.calculator.net/voltage-drop-calculator.html

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hotwaterjoe avatar image
hotwaterjoe answered ·

Thank you both for your speedy response. I’ll put the controller in the battery bay.

I was gonna try series and parallel and try to get a feel which would work nest for me.

Thanks again

Bill

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