question

airpress89 avatar image
airpress89 asked

MPPT 150/85 VECan

Hello.

I use a 48V battery system

My charger was running without problems with 2 Jinko Solar panels in serie for almost a year.(+-35v each pv) (around 70v in full sun, that's wat the controller said) Today I connected a third one. The MPPT showed a voltage from around 105v. (good margin as the controller can handle 150v "open pv voltage"

For a resaon it does not show the current coming from the pv. Other words it does not charge.

When I disconnect the third panel. It works great again with 2 panels. I reconnected the third one, same thing.

I'm missing something?

48volt charging
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2 Answers
dc-marine avatar image
dc-marine answered ·

Have you tested the new panel by itself ? Use a clamp meter to confirm output by measuring short circuit current (clamp your meter around the leads and plug them together to short the panel and read current in full sun, you can safely do it for a few seconds, long enough to get a reading). Also check open circuit voltage.


Also unlikely but double-check polarity of all panels. Also make sure the MPPT wants to enter bulk mode by power cycling (turn off both PV and battery connections).

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airpress89 avatar image airpress89 commented ·

Okay, I will test it with the clamps today if it's gonna be full sun today in Belgium; ;-)

Another thing I get in my head now.

I didnt connect the ground to the third panel because I wanted to do a test with a 3 one?Can this be the issue?

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airpress89 avatar image
airpress89 answered ·

Hello

Shorting the panel result in around 36v short circuit. Looked at the solar panel information paper and that a good reading. Also the short circuit current in full sun was around 14/15amps.

Also, the MPPT wants to enter bulk mode by power cycling That works also.


Can it be that the solar charge controller is not capable for 48V systems and 3 panels?(open circuit more then 100v) Are there Victron engineers here that can confirm this?


Edit: I did the mppt calculator test, my controller is capable of working with that configuration. In fact, it's capable of working with 3(435Wp) panels in serie and 4 strings.

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klim8skeptic avatar image klim8skeptic ♦ commented ·
@Airpress89 What is the Model and serial # of the mppt?
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airpress89 avatar image airpress89 klim8skeptic ♦ commented ·
150/85 Ve.Can A10D

Serienummer: HQ201883CP6

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klim8skeptic avatar image klim8skeptic ♦ airpress89 commented ·

@Airpress89 Check your mppt against the model # at the bottom of this thread.

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airpress89 avatar image airpress89 klim8skeptic ♦ commented ·
Thx!

Ohhh, What it’s only a 12/24v model? Why does the mppt calculator on the victron site choose this model of i select that I have a 48v system?

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klim8skeptic avatar image klim8skeptic ♦ airpress89 commented ·

@Airpress89 What it’s only a 12/24v model?

Only the 4 model / part numbers I linked to.

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airpress89 avatar image airpress89 klim8skeptic ♦ commented ·
These are suitable with only 12/24v you linked?
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klim8skeptic avatar image klim8skeptic ♦ airpress89 commented ·
@Airpress89 Yes. Those 4 models are only for 12 / 24v batteries only.
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dc-marine avatar image dc-marine klim8skeptic ♦ commented ·
But why would it work with 2 panels and not 3, just like in the other thread linked ? OP states it's been charging his 48v bank for almost a year using two panels at 70v, but not 3 at 100v.
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Justin Cook avatar image Justin Cook ♦♦ dc-marine commented ·
There's more power with 3 panels.


There was never an actual difference between -411 and -412 except that a component procured from an alternate supplier in the -412 models made them unstable at 36 or 48v charging, so they were derated and sold only as 12/24 models, at a substantially discounted price.


That the user managed to get away with charging a 48v bank with one of these cheaper derated units for this long is surprising, but observed instability at higher-power levels that are not observed at lower-power levels is not surprising.
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