Solar System Issues

[tommyleyland]

Hey guys,

I've got an issue with my solar system.

 

At the moment, I can leave my solar panel charging for 2 days, even with sun, and it won't go over about 70%. Even that will only last 2 hours watching tv or running 1 laptop.

 

I'm now not sure if I got a controller that's too cheap (eBay job), if I don't have enough batteries, (2 x 110amp leisure batteries with 2 more on standby), or whether the panel isn't powerful enough (Highly doubtful)

 

Maybe I might have not set up the controller properly such as setting the cut off voltage etc but I'm not sure what the settings should be.

 

A (poorly drawn) diagram of my setup:

 

If anyone has any advice on what I can try, I would be eternally grateful.

[Alenafour]

How do you know it won't go over 70%?

[tommyleyland]

Because the controller says the battery percentage on it. Unless it means something else...

[peterboat]

How old are the batteries and its not been that sunny so maybe they just need longer also how much does the tv draw. There are lots of variables so really more info will be needed to help. You could try running the engine to ensure a full charge then we could have a starting point by the way welcome to the forum

 

Peter

[TheBiscuits]

Try one battery at a time.

 

One or both of them could be shot, and if that is the case you will see different results on each battery.

[Guest User]

<..... am I the only one who read the title to this thread and thought, "Oh no! Has Jupiter crashed into the Sun?">

 

LCx

[RLWP]

<..... am I the only one who read the title to this thread and thought, "Oh no! Has Jupiter crashed into the Sun?">

 

LCx

 

On this forum - of course not. Have you heard, it's in the stars - next July we collide with Mars

 

And I'm gone

 

Richard

[tommyleyland]

They're both brand new 110amp batteries. The TV is a 240v 24" television but once my fuel pump has been reconditioned (ouch) then I'll run the engine and charge them to 100% to see how they last.

 

I just didn't know if adding more batteries might help or if a more expensive controller would make that much more of a difference

[Phil.]

At this time of the year and with fairly cloudy weather your panels won't be producing a huge amount. By way of example I have one 235 w panel charging via and Mppt controller and today it produced 46 amp hrs. My daily use is probably in excess of 170 amp hrs.

 

Edited to add....panel is flat to roof, would gain more if tilting type but does not look to good.

Edited September 17, 2015 by Phil.

[Phil Ambrose]

I would suggest some form of battery monitor rather than relying on the dubious percentage indicated by your PV controller. As has been said above you need to establish the true SOC of your batteries, you might find a hydrometer a useful tool to have (not expensive) It is also a good idea to do a power audit so that you know exactly what you are taking out of your domestic bank. I would guess that as you appear to be relying on your PV array for all your charging (engine U/S at the moment) not enough is going in during the day because it's not been too sunny and what sun there is has been getting lower in the sky (and will continue getting lower as the year progresses)

Phil

[peterboat]

More batteries will help at the start but at the end you will just have more flat batteries I suspect the 70 percent figure will be correct their just isnt enough sun at this time of year to charge up the batteries so its time to fix that fuel pump sorry

 

Peter

[bottle]

and get it fixed, quickly because if the gauge is wrong (it will almost definitely be) then you could be needing new batteries very soon.

 

It does not take long to ruin any batteries new or otherwise if they are not charged correctly on a regular basis.

 

You can almost disregard solar at this time of year and onwards into winter.

[Peter-Bullfinch]

No, Bottle, solar is very useful in keeping batteries topped up for those of us who use our boats irregularly during the very coldest months.

[Arthur Brown]

My lappy uses less than 100w from it's charger, so lets assume 100w goes into the charger. 100w at 12ish volts is 8.5 ish amps, so in two hours you have used 17amphours.

 

17 AH out of a 220AH bank is almost nothing so to get the bank flat it must have started with 17amphours in there. This means that the battery was effectively flat before you started to use it or the battery is so sulphated that it now only holds 17AH.

 

Feed your battery some electricity NOW.

 

While 225w of solar will charge your batteries you are using more than they supply and this will get worse as winter approaches. Can you access mains from a shoreline or make arrangements to charge the batteries in a boatyard, even charge them from a car for a while.

[Tom and Bex]

Firstly if you are reading the state of charge from the solar controller and it is a Tracer or similar then ignore it. It is a complete work of fiction and bears no resemblance what so ever to true SOC. What controller do you have? If a PWM controller and a single 225W panel it will be seriously under performing.

 

You also don't mention a fridge. Do you have an electric fridge running? If so this will be your biggest consumer of power. You say it only lasts 2 hours watching TV, what happens after this time? Is it just the controller saying 0% or does the TV cut out due to low voltage? Presumably you have lights, pumps etc running as well?

 

As others have said you really need to get a decent charge into your batteries as soon as possible to prevent permanent damage to them. We have 500w of solar and if we have a run of a few cloudy days at this time of year we need to put some extra charge into the batteries via engine or generator. That is with an electric fridge though.

 

Cheers

 

Tom

[bottle]

and get it fixed, quickly because if the gauge is wrong (it will almost definitely be) then you could be needing new batteries very soon.

 

It does not take long to ruin any batteries new or otherwise if they are not charged correctly on a regular basis.

 

You can almost disregard solar at this time of year and onwards into winter.

 

 

No, Bottle, solar is very useful in keeping batteries topped up for those of us who use our boats irregularly during the very coldest months.

 

What do you mean No, where did I say solar was not useful.

[Terryb]

Hello again

 

While you clever bu*&5rs are on the subject. I would like a bit of input if that's OK. I have recently fitted 4x100 12v panels with a properly matched MPPT controller.

I have done a usage audit and it would seem to me that something aint quite right.

I run my tv for 5 hours a day 3.5 amp

I have been leaving my laptop on charge all day (think this may be the problem) the adapter says its 12amp (but that sounds too much)

I have no fridge all my lights are led the only other use is occasional charging of toothbrush and camera battery less than 1 amp for a few hours a week.

3x110ah batteries new in April. 70Amp alternator, (seperate alternator and starter system)

I only have one readout at my disposal. My questions are

1/ should I get another source of info/charge controller/etc

2/ do I need more batteries (2 more ready to fit)

3/ is my lappy causing the problem.

4/ link to my readout today bright day no direct sun, comments please http://imgur.com/oq4voji

5/ any advice will be taken on board with the good will that was intended

 

Cheers guys

[Tony Brooks]

Buy yourself a £20 to £30 digital multimeter or a bit more if you want a DC clamp type ammeter in with it.Then starts taking voltage measurements as soon as it has got dark (so no solar to mess the readings and a bit of previous discharge) also firts thing in the morning while still dark. Come back, tell us what they are and we will give you a fair idea of ho well charged the batteries are.

 

Consider with battery off load and rested 12.7 to 12.8 = about fully charged

 

12.5 = 3/4 charged but consider half charged for optimum life.

 

12.2 to 12.3 = 1/2 charged but considerer it as fully discharged for optimum battery life.

 

Less than 12.2 - the more often and the lower you go the more you shorten the life of your batteries.

 

By all means buy expensive gizmos if it makes you feel better but a bit of time with a reliable ammeter and voltmeter and leaning what the readings mean is by far the cheapest and some may say the bets way of understanding what is going on.

 

You have had plenty of tie to ruin those new batteries if you have not been fully charging them regularly or have been over-discharging them.

 

MY 330Ah domestic bank have been in use for about 3.5 years now and still seem to be fine and I only have a 60 watt solar panel with a PWM controller but when I am n the boat I am a bit fanatical about keeping the batteries as fully charged as possible and never going below 12.3. I have an electric 12V fridge, run a laptop (only charge it when the engine is running or before starting the engine for the day, and a mix of florescent and LED lamps. 70 amp alternator.

 

By the design and general look of the controller I would not trust it - is it an Ebay job?

[Sea Dog]

Whilst I can't comment authoritatively on your questions, I had reason to draw a similar conclusion about laptop charging. I now only plug on my laptop when cruising and disconnect it at all other times. I use it as long as the batteries last and think twice before recharging it from my domestic bank, depending on state of charge and next setting sail.

[Terryb]

.

 

By the design and general look of the controller I would not trust it - is it an Ebay job?

Hi Tony and thanks. I had the whole system fitted by ( very widely approved NB users) a decent company so I'm of the belief that all is well.

I do have a couple of volt meters so do I just take a reading across the two main poles

[Tony Brooks]

If you have and can use a voltmeter then definitely check the leads between the controller and the LEAD of the battery post for voltdrop. The important voltage is the off load and off charge voltage after a fair while off charge or after a small load has been applied and the removed. Take this between the LEAD of the two battery posts. That way you find out what is happening actually at the battery.

[Graham.m]

So what was the result, good or bad readings?

[ditchcrawler]

So what was the result, good or bad readings?

We havent had any sun since then so they are flat

[Graham.m]

We havent had any sun since then so they are flat

 

And ready for recycling