Solar panel readings

[macker1]

I bought a solar panels kit of ebay a while back two 100w panels , fitted them a couple of weeks back but the controller that came with the panels did not seem to be right as it was not showing the panels, with a meter i could see the panels where producing electricity. I bought a new controller and fitted it to day. can any body tell me if the readings are right. The batteries where at 12.3v (next job is to clean the roof)

 

[Phill D]

if your batteries were showing 12.3v then it likely they were in need of some charge hence the 14.2v and 7.1 amps from the solar panels.

 

[JockandRita]

macker1. Your plastic roof light needs pushing out again.
It's meant to be domed so that the water runs off it, rather than collecting on it.

I'm with Phill D, re the battery voltage and the readings on your display panel.

Cheers,

Jock.

 

[pappajohn]

7.1amps at this time of year seem a bit optomistic to me.

 

[pappajohn]

Duplicate post.

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[Driventemple]

Fit the Remote Meter so that you can see more clearly what's happening. I fitted an Epever MPPT and Meter to my last van and the information given was very clear, telling you what the panel was producing and what was going to the batteries.
https://rover.ebay.com/rover/1/710-...0001&campid=5338547443&icep_item=233476652922

 

[Off da Grid]

I would say the readings are about right if it’s an mppt controller.
Is 12.3v about 50% charged?
My Votronic mppt controller would show around that figure with my 255watt panel at that state of charge on a day like today a sunny cloudless sky.

 

[macker1]

Yes the dome does need pushing back, I leaned on it when fitting the panels I am thinking of replacing it with a more modern one.

 

[dunnah01]

My 2 X 180 Watt panels and £5 PWM controllers were giving 16a when the sun was shining so 7a from 200 Watts and a posh controller sounds very doable

 

[macker1]

I would say the readings are about right if it’s an mppt controller.
Is 12.3v about 50% charged?
My Votronic mppt controller would show around that figure with my 255watt panel at that state of charge on a day like today a sunny cloudless sky.

Yes is a Epever MPPT controller i have kept the battery's of charge for a couple of days using lights and water pump to discharge them.

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[macker1]

Just another quick question I have not got any thing connected to the load side of the controller. Can any one recommend what to connect to it. all my 12v system comes out of a Power management Pms1 system.

 

[dunnah01]

I'd just connect it directly through to the leisure battery with an inline fuse. Once you get your head fully around the workings of the power management system you may find a better way to plumb it to give a more convenient display than the solar controller

 

[DBK]

If 7 amps are going in and the battery voltage under charge is 12.3v then the batteries are almost certainly dead. If they were 12.3 before charging then things are probably fine but not knowing what the voltage is under charge would be a concern to me. You don't know what is happening.

 

[macker1]

If 7 amps are going in and the battery voltage under charge is 12.3v then the batteries are almost certainly dead. If they were 12.3 before charging then things are probably fine but not knowing what the voltage is under charge would be a concern to me. You don't know what is happening.

Yes they where at 12.3v before charging I had run them down before connecting the solar panels I have the on board charger charger turned of at the moment normally they are about 13.4v when charged. I will check them to morrow morning to see how they have charged up

 

[DBK]

Yes they where at 12.3v before charging I had run them down before connecting the solar panels I have the on board charger charger turned of at the moment normally they are about 13.4v when charged. I will check them to morrow morning to see how they have charged up

Thanks. That sound fine I think. ?

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[Lenny HB]

You say you have 2 x 100 watt panels but one looks a lot bigger than the other.
7.1 amps from 200 Watts at this time of year is very doubtful. I have 300 Watts with a Votronic MPPT regulator and Friday with bright sunny clear sky I was getting 7 amps at midday.

 

[macker1]

You say you have 2 x 100 watt panels but one looks a lot bigger than the other.
7.1 amps from 200 Watts at this time of year is very doubtful. I have 300 Watts with a Votronic MPPT regulator and Friday with bright sunny clear sky I was getting 7 amps at midday.

Yes they are both the same size (it might be the angle of the photograph) it was very sunny when I took the readings

 

[macker1]

Good morning all, it is a nice sunny morning in Warrington, just took some readings of the battery's 2 x110amp both showing 12.8 v and the same reading on the controller. some readings from the panel. forgot to mention the readings yesterday where at 15.00 it went overcast about 19.00 the readings this morning 7.35

 

[dunnah01]

That all looks fine to my untrained eye

 

[Lenny HB]

Yes they are both the same size (it might be the angle of the photograph) it was very sunny when I took the readings

Just seen you are in Warrington, I'm on the south coat I don't believe the 7.1 amps is accurate, 4-5 amps more realistic.

Good morning all, it is a nice sunny morning in Warrington, just took some readings of the battery's 2 x110amp both showing 12.8 v and the same reading on the controller. some readings from the panel.

Something not right there unless the regulator you have bought is not a multistage charger.
Decent multistage regulators will charge the battery to 14.2 v then hold that voltage for the absorption phase (time set by type of battery) then drop to a float of 13.8v.
12.8 indicates no float charge.

Edit:
I just realised you only just took those readings before 8 am so what I just said could be a load of bol**ks.
The batteries will have settled overnight and when the sun came up the charging cycle will have started again. If there is no load on the batteries being fully charged last night with the sun being up for over 2 hours I would have expected the voltage to be ramping up towards 14v by now.

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[dunnah01]

A sun that low in Warrington will probably only be managing 10 watts so half an amp looks about right

 

[Dazzlin]

A lot depends on the state of the batteries when analysing the charge rates.

It was a long time before I worked this out when looking at amps achieved by folks.

Having just fitted my batteries earlier this year and not used the van with much yet, and having read you need to flex the batteries before getting to their full potential, I have left the 230v fridge on. The inverter is using 0.5 amps an hour and the fridge 4-5 amps when running (5-10 mins 2-4 times an hour)
All items are freshly fitted.
2 x Trojan 6v 235ah batteries
2 x 100w mono solar panels (connected in series)
Epever solar controller and monitor.

Both the MT50 and the Nasa Bm1 battery monitor show 12.5 - 12.6 at daybreak and I was happy to be getting nearly 9 amps at just after midday a couple of days ago.

 

[macker1]

Just seen you are in Warrington, I'm on the south coat I don't believe the 7.1 amps is accurate, 4-5 amps more realistic.

Something not right there unless the regulator you have bought is not a multistage charger.
Decent multistage regulators will charge the battery to 14.2 v then hold that voltage for the absorption phase (time set by type of battery) then drop to a float of 13.8v.
12.8 indicates no float charge.

Edit:
I just realised you only just took those readings before 8 am so what I just said could be a load of bol**ks.
The batteries will have settled overnight and when the sun came up the charging cycle will have started again. If there is no load on the batteries being fully charged last night with the sun being up for over 2 hours I would have expected the voltage to be ramping up towards 14v by now.

Yes it was showing 14 amps going in at 7.30, Thanks for the input as this is all new to me.

 

[Lenny HB]

Yes it was showing 14 amps going in at 7.30, Thanks for the input as this is all new to me.

14 amps totally impossible from 200 watts.
When if you have panels that are well above spec you might manage in southern Spain mid June around midday.
In Warrington in April 5 amps max.

 

[Lenny HB]

Both the MT50 and the Nasa Bm1 battery monitor show 12.5 - 12.6 at daybreak and I was happy to be getting nearly 9 amps at just after midday a couple of days ago.

Sorry just not possible from 200 watts at this time of year in the UK.

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[macker1]

Sorry just not possible from 200 watts at this time of year in the UK.

my mistake should have said 14 volts not 14 amps this electricity thing is a bit confusing

 

[Lenny HB]

Just remembered the BM1 used to have a problem measuring current giving false readings when solar panels are connected. That was the reason I bought a Victron BMV700.

 

[autorouter]

Just another quick question I have not got any thing connected to the load side of the controller. Can any one recommend what to connect to it.

Nothing at all. Ignore the load connections. They are not used in motorhome applications - you have the PMS box as you said. These controllers are also used for powering self-contained remote lights, CCTV cameras, road signs etc, when the load connection is useful.

 

[macker1]

Nothing at all. Ignore the load connections. They are not used in motorhome applications - you have the PMS box as you said. These controllers are also used for powering self-contained remote lights, CCTV cameras, road signs etc, when the load connection is useful.

Thank you for the information, learning as I am getting older also passing the time away nicely while not being in lockdown

 

[Dazzlin]

Just remembered the BM1 used to have a problem measuring current giving false readings when solar panels are connected. That was the reason I bought a Victron BMV700.

My Bm1 shows 0.5 amp lower than the MT50.

Bm1 shows net charge figure (inverter draws 0.5 amp)
MT50 shows solar charge from controller to batteries.

Not bright n sunny often here in Stirling, where we are at the mo, but when it is I am pleased with the 'solar harvest' I am getting......

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