Flickering LEDs when i use my laptop HELP!

[Neil the newbie]

Hi there, i have a problem where I can't use my laptop on my 12v system even though my (probably terrible) maths says it should work fine.

Ill give you the specs first

290 w Solar Panel
PWM charge Controller
110 AH Leisure battery CCA 800

Laptop = Macbook pro, DC power supply is 11.6 - 16 v @ 5.6 A max (so the label says) the actual plug is fused with a 15A Fuse !!

What happens is when i plug my laptop in, the Led lights in my caravan go dim at first and then start flickering, getting more and more violent. the fuse box is fused with 8 amp fuses all the way except for where the main lead from the battery connects to it with a 16 A fuse

my laptop charges for a bit and then the charger just stops working.

A couple of times I've kept it on long enough and its actually pushed the fuse out and slightly melted it Suggesting the fuse is too big.
Changed it to a smaller one, but flickering continues.

My laptop showed fully charged this morning, however the lights were flickering very slightly without anything else plugged in. When i plugged the laptop in in wouldn't charge it at all.
yet sometimes, it will actually charge my laptop if i don't use it at the same time, and don't run any lights.

But there seems to be no rhyme nor reason as to when it will or won't charge, relating to the level of charge in the battery.
This battery is brand new as well so would be amazing if it was faulty.

If i try and use my 100 w inverter with my laptop it just overloads and reads not enough power, if i use my 150 w inverter the lights still flicker.

Ive gone through and all connections seem to be ok.

am i using the wrong wire or something, for the life of me i can't work it out.

if anyone here can help i would be so grateful this is doing my head in.
i think I've supplied all the info i have, but ill try and supply more if needed.

Many thanks
Neil.

 

[solarfred]

What voltage is the battery? I mean what is the SOC?
What is the spec of the controller?
What is the voltage (voc) of the solar module?

 

[Neil the newbie]

What voltage is the battery? I mean what is the SOC?
What is the spec of the controller?
What is the voltage (voc) of the solar module?

Hi, the battery is 12v fully charged 100% If thats what you mean?
the controller : 30 a pwm 12/24v
and the solar panel is 12/24v compatible 290 w (how do i work out the open circuit voltage) I'm sure it was just 12
[h=1][/h]

 

[solarfred]

I mean what is the exact voltage of the battery at this moment in time.
The panel cannot be 12 and 24 volt compatible. It is likely to be 30-40volts voc? Is there no label on the back?
The controller is PWM so can only handle about 15-18 volts and the rest is wasted power from the panel. To get maximum power from a high voltage panel you need an MPPT controller.

It sounds like you have low voltage in the battery but please check with a good quality volt meter. It should be 12.75+

A decent 150w inverter will charge the laptop. What make is it?
What make is the battery?
What LED lights are they? Mains 12v or DC 12v?

 

[Neil the newbie]

I mean what is the exact voltage of the battery at this moment in time.
The panel cannot be 12 and 24 volt compatible. It is likely to be 30-40volts voc? Is there no label on the back?
The controller is PWM so can only handle about 15-18 volts and the rest is wasted power from the panel. To get maximum power from a high voltage panel you need an MPPT controller.

It sounds like you have low voltage in the battery but please check with a good quality volt meter. It should be 12.75+

A decent 150w inverter will charge the laptop. What make is it?
What make is the battery?
What LED lights are they? Mains 12v or DC 12v?

Well the battery reads 13.6 volts (with a good voltmeter) during the day when charging, and 12.6 or 7 at night when its not.
The battery is brand new, so it shouldn't be duff. The make is Advanced Leisure.

the 150 w inverter was eCAN

And now you mention is i think i remember the panel being 40 Volts Voc. and its a 12v solar panel.
The battery charging doesn't seem to be the problem. its just using my laptop.

 

[solarfred]

OK so the battery seems good. You are connecting the lap top charger to the Inverter socket. How are you connecting the inverter to the battery?.

The panel at 40v sounds right. You will be using about 18 of those volts in a 12v system.

 

[Neil the newbie]

OK so the battery seems good. You are connecting the lap top charger to the Inverter socket. How are you connecting the inverter to the battery?.

The panel at 40v sounds right. You will be using about 18 of those volts in a 12v system.

It connects via the fuse box with an 8 amp fuse. and plugs in to a cigarette lighter socket.

 

[solarfred]

Does the cigar socket connect direct to the battery from the fuse?
Can you connect the inverter directly to the battery and eliminate the laptop charger and inverter.
You then have a solar controller wired directly to the battery so panel - controller - battery? A fuse between the controller and battery?

 

[Gavin A]

your inverter is probably a cheap square wave / modified sine wave inverter, operating towards the top of its limits, and the lights are flickering due to the voltage fluctuations or similar.

thin cables from the battery to the inverter would make this issue worse as well.

 

[solarfred]

I use a 150w MSW "cheap" inverter on my mac pro and it works fine so if we can eliminate these items we can look elsewhere is my theory.

 

[Sonic98]

I have a similar problem. I bout a 100W power inverter from a company called MicroSpec. I noticed the first time I used it, it seemed to blow the fuse to the lighter in my work truck. I took it back to my car. It was working, but it started off popping and other things that made me think it was faulty. I took it and exchanged it. It has worked fine in my car ever sense. I've been waiting for them to come change out the fuse in my work truck for months. Finally they sent someone out who couldn't get the fuse out. Later I found my pliers as was as the spare fuses. I can actually charge my phone and iPad at work without having to go to my car. I can't, however charge my laptop. I plug in the inverter, and it seems to work fine. But was soon as I plug it into the laptop, the power light starts to flash. The light on my charger barely stays lit. It works fine in my car but not in the truck. It's a 15A fuse. I looked up what fuse would be in my car. It says my car has a 20A fuse going to the lighter. I really don't have the electrical specs on the laptop at this time, but the laptop is a Dell Latitude 5540 I think. I would change it out and get a pure wave inverter, but it works fine in my car. Not sure if it would be a waste of time.

 

[Gavin A]

you need to allow for the losses in conversion from dc to ac to dc, with cheap kit they're probably 20% losses each conversion, so an 8A charge to the laptop would take 8 x 1.2 x 1.2 = 11.5A, then allow for the voltage, which is often around 19V on laptops, so 11.5 /12 * 19 = 18.24A actually being drawn from the battery by charging a 19V laptop battery at 8A through a cheap inverter.

And batteries don't really like being drawn from at those sorts of levels, which are approaching C5 levels of discharge - ie full discharge in 5 hours, which significantly reduces the battery capacity.