Output of solar panel variance

Craig1 · Guru

Output of solar panel variance

Jaahn · Guru

Hi Craig smile

I am not sure what you are asking ? You have one faulty panel and controller, and now have another panel which is also faulty and a new controller. Most 12v panels will put out about 22-24v when open circuit and in full sun. Any good controller for a 12v panel should be able to handle that without any worry as it will get up to that when the battery is charged and it switches to float or charged mode. hmm

If a panel is only putting out 4.4v under load then it seems that there is a very high resistance in the circuit. Either the wiring, the connectors, the diodes or internal to the panel. This could be checked and found by a sensible technician with a multimeter. The panel could be directly connected to a battery for testing if you do not have any other good controller to use. I assume you have two panels now that are "faulty"and they are both doing the same thing, if i understand what you said. If so that would point to a serious wiring connection problem. confuse Again a skilled technician and mulitmeter will be your friend. aww

Jaahn

-- Edited by Jaahn on Friday 9th of March 2018 10:41:37 AM

T1 Terry · Guru

First things first, the Vic Off road panel, is it a semi flexible or a rigid panel? Next, does it have its own controller or do the cables come direct from the panel connector box?
Do you have a method of testing the current flow (amps) running through the solar cables? If you do, try connecting the solar cables from the panel function box directly to a 12v battery and measure the voltage at the battery before it is connected, when first connected and continue to measure the voltage to watch if it increases over time while the panel is in full sun. It is important to disconnect the solar panel if the battery voltage exceeds 14.8v. If the battery voltage is increasing but you can see you have some time before it will reach the 14.8v point, measure the current coming from the panel and compare that to the advertised Imp output marked on the back of the panel. Don't panic if it is a bit less, that figure requires a perfect sun angle to achieve, you are just look for a figure that is better than half that advertised output figure with the panel in full sun. If you get these 2 things to happen then the solar panel is ok.

T1 Terry

Craig1 · Guru

Jaahn,
No, still the original panel, but new controller rated to take up to 33v input. The voltage drop occurs once the panel is connected to controller which then triggers a " low voltage input alarm". Craig

Jaahn · Guru

Craig1 wrote:
Jaahn,
No, still the original panel, but new controller rated to take up to 33v input. The voltage drop occurs once the panel is connected to controller which then triggers a " low voltage input alarm". Craig

Hi Craig smile

Perhaps we should do the Doctor bit and ask for a complete history. biggrin

How long have you had the panel and the dual battery controller. Has the controller worked before on its own as a dual battery system before the solar panel was fitted?

Did the solar panel work for any time after fitted before the controller fried.

Solar panels cannot generate larger voltages than their rating so the controller should have been OK if it was rated for the Vmax of the panel. A volt or two extra should not do any harm. If it did fry the controller it was cr*p. I would look elsewhere for that cause.

My original statement "a good technician with a multimeter" should find if the panel has an internal fault or there is a very bad connection in the junction box, a bad diode, or one of the connections. Possibly a badly crimped connector if you have them or even your Anderson plugs. hmm

Jaahn

Craig1 · Guru

Maximum Power(Pmax)
130W
Open-Circuit Voltage
22.5V
Short-Circuit Current
7.55A
Maximum Power Voltage
18.3V
Maximum Power Current
7.10A
Maxium System Voltage
1000 VDC
Temperature Range
-40°C to +85°C
Solar Cell
Mono
Product Dimension
1010x30x670mm
Weight
8.0kg
Above specs from Vic Off Road website.It is a ridgid fixed panel. Wires come out of a junction box on back of panel which says it has over voltage protection built in.

We have measured 24 volts output several times,both TJM and myself.

Original TJM controller worked fine for 9 months charging second battery from alternator prior to connecting the VOR solar Panel

Once I connected it, I had it covered when I plugged it in, the low voltage alarm was triggered on the TJM Controller, which then literally fried the next day after disconnecting the panel. The original controller was only rated to 23.5 volts.

After TJM replaced their controller with an updated version, the out put was measured at the Anderson junction plug underbonnet- Hence 4.4 volts underload. This again triggered the" low voltage alarm".
Wire is 6mm,not including insulation and sized by auto elec who understands solar requirement, from panel to junction box, around 1.5 metre run.

Next step is auto elec I think as I cant measure amps.
cheers Craig
Still awaiting a reply from Camec, so must have them a bit stumped as well

Barboots · Senior Member

Based on what I just glanced over at http://www.tjm.com.au/en-oceania/products/electrics/battery/battery management , both their systems are multivolt and suitable for both 12V and 24V installations. From what you mentioned, I'm wondering if their system isn't somehow going into the 24V mode due to the open-circuit panel voltage, which is then "low voltage" for 24V when under load. Something is fishy...

Jaahn · Guru

Hi smile

Hard to tell from my computer keyboard biggrin Needs a meter putting on a few things to check the basic set up and panel output !

My only other comment would be, are you sure the panel is wired up with the polarity correct to the controller input ? To answer that you must check it first, not just say yes.

Jaahn

oldtrack123 · Guru

Jaahn wrote:
Hi
Hard to tell from my computer keyboard Needs a meter putting on a few things to check the basic set up and panel output !
My only other comment would be, are you sure the panel is wired up with the polarity correct to the controller input ? To answer that you must check it first, not just say yes.
Jaahn

A BIG Ditto to that,but both the panels & battery polarity

The panels specs are ok.

Certainly needs a multi meter ran over it

-- Edited by oldtrack123 on Saturday 10th of March 2018 01:13:00 AM

Craig1 · Guru

Well,99.99999% sure about wiring,(did go over and over before doing plugs up) BUTTT I will pull it of and triple check
thanks all, Craig

Craig1 · Guru

Well, found a new owner of existing business today, Lavington Auto Elec, Union Road Lavington, Matt. He checked volts, got same answr as me( 4-4.5v), then charge rate in full sun, yes there was some, checked again under load of 15 degree fridge which had been off, so battery voits went down. Input voltage from panel then started to fluctuate, so did amps with clamp meter, low but a bit there.
Suggested I borrow a different panel, so I did. One of 4 120w from brother inlaws canopy, simple one bolt remove.
Wow whole different scene.
3.5 amps in just angled towards sun at 1pm esdstime, almost 14 volts at 2nd battery, so looks like a dud panel,(I can pick the dud in almost anything lately).
Also, I had wired correctly with adequate wire.

As I removed the fitted MC4 plugs and replaced them with the supplied by vic offroad anderson plug, I doubt if a warranty will succeed. Plus around $30 to get it back there.

Thanks to all again Cheers Craig