solar panel output?

[al n sal]

Hi everyone,

I.m afraid I know next to nowt about solar power, but I have bought and fitted and set up, 80watt panel and charger £199.99.

everything seems to work properly, but as the controller is a cheap one only has led lights. so I can't tell if it is

I put my meter across the leads into the controller from the panel at two different points in the day, (very wet and very overcast) got a max reading of 8. something volts,

can someone tell me if this sounds about right.

thanks

al

 

[Firefox]

If that's what the input was it was too dull to develop enough voltage to start charging your leisure battery. The output from the controller needs to be greater than the voltage of the battery ie Approx 13-15v similar to an alternator charger.

The main job of a controller is to limit the output when it is very sunny to prevent overcharging. In this case you were at the opposite end of the scale. Try testing on a sunnier day. If it's still less than 12V you have a problem with the panel or the controller!

Also try testing the voltage output to the battery rather than the input to the controller if possible.

 

[syldale]

solar panels

hi al n sal. i bought a 120watt panel off internet £385 and the controller was also a cheap so got new one off ebay 20amp all singing and dancing £49 we have 3 120amp batteries come rain or shine they are always full even cloudy day it puts 2 3 or 4 amps if your batteries are down it will put max amps in on a sunny day it can bang out 8 amps easy . the best way to test it is connect a battery what pretty flat and see if it charges up and keep taking readings another way put a dark blanket over the panel look at your controller's lights then take the blanket off and check again but this time of the year you will not get full amps bit long winded i know but it works. happy camping

 

[al n sal]

thanks guys

will try when it gets a little clearer.

firefox, wont the power out of the controller just read the LB power?

syldale, do you get a big voltage drops in dull weather too, I know its the amps that charge, I'm just really trying to check that the panel is working, as I don't have much techy savvy, it the only way I could think of,of checking it

I hve two 110 amp LB's, both are fuly charged, so unfortunately won't be trying to pull power,

thanks again

al

 

[syldale]

solar panels

thanks guys

will try when it gets a little clearer.

firefox, wont the power out of the controller just read the LB power?

syldale, do you get a big voltage drops in dull weather too, I know its the amps that charge, I'm just really trying to check that the panel is working, as I don't have much techy savvy, it the only way I could think of,of checking it

I hve two 110 amp LB's, both are fuly charged, so unfortunately won't be trying to pull power,

thanks again

al

hi . if your batteries are topped up it will only trickle charged the only way to be shore is run the batteries down what i did for a test was put a blanket on the panel turn t.v on ran it all day take blanket off then in the morning check and if the volts go up the panel is working my last m/h had an 85 watt but was not up to speck for me because this time of the year they don't put much in .happy camping

 

[al n sal]

thank you

will give it a go tomorrow

al

 

[Kontiki]

Like you say its the amps that matter, as well as the solar panel on the roof I have one of the small ones to sit on the dashboard (useless) this will show 18 volts but next to nothing in the amps. You can check how many amps your panel is giving by fitting your meter in the line. If you fit an in line fuse in the wiring you can get an adapter from Maplins that you can plug into the blade fuse holder.
Car Fuse Adaptor Lead Set

 

[Firefox]

Yes you'll have to disconnect the leisure battery temporarily to read the true controller voltage output.

But if it's less than 12v it won't be doing any charging of the battery.

As I understand it the controller is primarily to regulate excessive voltage, and prevent overcharging. If they have step up 8V to over 12V then this would really cut the charging current down to negligible espec when it's dull, so they don't step up low panel voltage as far as I know.

 

[al n sal]

thanks guys

will look for the fuse plug in, guessing its an ammeter

al

 

[Kontiki]

If you have a multi meter (you can pick a digital one up for about a fiver, always handy to have) it should be able to do amps. If your local Maplins is anything like ours the guys are always helpful in giving advice on what you need & how to use it.

 

[Firefox]

You can do amps with a multimeter as Kontiki says but it's slightly more tricky. You have to select the right range and connect the meter in series.

If you check the voltage first, and it is less than 12, you wont be doing much charging because water doesn't flow uphill and neither does current

 

[AndyC]

The original message said that it was the panel voltage that had been checked, I would have expected that to be well above 8 volts even on an overcast day.

It would be useful to check again on a sunny day, the panel should be giving something over 17 volts in sunlight.

AndyC

 

[al n sal]

thanks guys

have popped back from work as it brighter today, not direct sun but definately brighter, checked the volts as before and its up to 12.75, and the charge light is on on the controller, yippeee, so it gotta be working.

i am a little worried bout disconnecting the wires from the controller to the LBs, as it says "WARNING! connect load, battery to controller then panel, Do not reverse" and as I'm placed zilch on the techy intellegence scale thought I'd best leave well alone, seems to be working.

now just got to find out where the water leak that hs appeared in the vroof is coming from, keeps yer busy this campin lark, dunnit

thanks again guys

 

[Firefox]

Yep no need to disconnect battery it if it seems to be working now. They probably tell you to connect to load battery first in case you accidentally short together the output leads while hooked up to the panel which may blow a fuse or a component in the controller.

12.75 seems low though. I'd expect 14 to 17V on a decent day which the controller will then moderate to give a charge voltage to the battery.