What Voltage To Set Controller To? (1 Viewer)

[friar tuck]

Hi I've recently installed a 200 watt solar system and I have noticed my mppt controller is adjustable for output voltage.it came set at 13.8v.im wondering if maintaining the batteries at a constant 13.8v all day will cause over charging and excessive gassing leading to electrolyte loss?

 

[Wildman]

it is adjustable so that you can change the setting for lead acid or gel batteries. My pair of leisure batteries have been set to 13.8 since 2001 and only just failed so I am confidently guessing it does them no harm, hee hee.
12V LEAD ACID BATTERIES
Although a battery is called a '12 volt' battery, its voltage varies from about 12.6 volts down to 10 volts when it is discharging and can rise to 15 or 16 volts during charging. It is very important, however, to limit the maximum battery voltage during charging otherwise the battery will be damaged. The battery voltage should not exceed 13.8 volts for long periods and 14.4 volts for short periods (8 hours maximum).

Gel Batteries
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[friar tuck]

Seems a reasonable length for a test period! I will leave it set at that it also feeds via a relay to the engine battery same principle as van bit relay so I assume the engine battery will be ok too?

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[Techno]

What Mppt is that?
Mine charges at three different voltages depending on state of charge from 13.4 to 14.4 float bulk and absorption. If yours only charges at a fixed voltage it's not a true mppt.

The float voltage for vented batteries with mine is 13.2 and for sealed 13.4 Gel 13.7
Bulk charge for all is 14.3

 

[SomeoneElse]

friar tuck
Is your controller one of these Broken Link Removed
If so I suggest you leave it at the factory settings, or...
A better suggestion is to replace it with a proper MPPT controller

 

[Techno]

friar tuck
Is your controller one of these Broken Link Removed
If so I suggest you leave it at the factory settings, or...
A better suggestion is to replace it with a proper MPPT controller

That is one of many frauds and even has the cheek to compare theirs to one that might actually be an mppt although that looks dodgy too

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[friar tuck]

It's exactlyly that model .so hour saying it's a fraud! I'm wondering whether it is worth complaining to the supplier?

 

[Techno]

Not really they know full well that people buy purely because they claim it is MPPT. They know full well that it isn't.

Any MPPT has two toroidal coils that are amongst other components essential to the way they function. They are actually claiming that the one in their picture works less efficiently because of the single coil whilst theirs has none at all . They are both very poor.

 

[Techno]

This is what you should expect of MPPT internals and 3 or 4 times more expensive

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[friar tuck]

It will still do an ok job though ?

 

[Techno]

It will still do an ok job though ?

Yes it will work as a regular PWM but I don't know how well.

This is one of two videos


Looks like its not a real PWM either

 

[cruiser]

thanks a lot techno100. I now know what to look out for.

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[Techno]

Having watched video 2 I'd bin it.
Be sure to leave negative feedback!

 

[SomeoneElse]

Yes it will work as a regular PWM but I don't know how well.

I think its worse that that. I haven't check the internals but when I monitored its operation I found that it always ran the panel at the battery voltage plus 0.75volts, until the voltage originally mentioned is reached.
I assumed that the controller was just a power transistor which is normally wide open and only gets modulated when the battery voltage rises. The curent is then reduced and the panel voltage rises along its IV curve. Very crude, at least a PWM controller would run the panel at an assumed (fixed) max power point.

 

[Techno]

This is what a real mppt does. I have 300 watts of solar and under the sky that was available for this picture (my panels are only rated at 5.5amp output each) here it has massaged the watts and voltage (simplistic) to increase the current to 14 amps where a PWM would be sending 11 at maximum. I have seen 22 amps at times.

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[scotjimland]

This is what a real mppt does. I have 300 watts of solar and under the sky that was available for this picture (my panels are only rated at 5.5amp output each) here it has massaged the watts and voltage (simplistic) to increase the current to 14 amps where a PWM would be sending 11 at maximum. I have seen 22 amps at times.

Hi Andy

My Hymer came already fitted with 2 x 80watt panels and a EPHC 10A PWM controller.. like this Broken Link Removed

it says it has "Pulse Width Modulation with four stages of charging" and I've witnessed this happening on the battery voltage meter .. so don't doubt the claim..

question is, would I be better fitting an MPPT ?

what make / model is your controller ?

I may fit more panels depending on how it goes this year .. in which case I would need a bigger controller anyway..

 

[Techno]

The one I've used since its earliest incarnation is now used by dozens of people across a number of forums. It has been constantly improved over the last 4 years to the current model. It is available as 200 or 300 watt and will cost circa £100 inc Parcelforce fee if unlucky. Personally these are all I use now.
This is mine but look at sellers other items for the slightly cheaper 200 watt
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[Techno]

Yours will be very similar to this internally. Many cases share the same board just dressed differently.

The 30 amp version of yours sub £11
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[scotjimland]

Thanks @Techno100 .. will probably upgrade it soon, good price..

 

[Techno]

Thanks @Techno100 .. will probably upgrade it soon, good price..

After sales service as been tried and tested and first class Big difference between Taiwan and China

 

[mikekaren2]

This is what a real mppt does. I have 300 watts of solar and under the sky that was available for this picture (my panels are only rated at 5.5amp output each) here it has massaged the watts and voltage (simplistic) to increase the current to 14 amps where a PWM would be sending 11 at maximum. I have seen 22 amps at times.

Techno, I have the same MPPT controller as you, what number setting should I have it in for this battery GF12025YG Sonnenschein Battery?

Mike

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[Techno]

https://www.tayna.co.uk/GF12025YG-Sonnenschein-Battery-GF1225YG-GF-12-25-Y-G-P269.html

If a sealed lead acid? number 2

EDIT says GEL so set to GEL number 03

 

[mikekaren2]

https://www.tayna.co.uk/GF12025YG-Sonnenschein-Battery-GF1225YG-GF-12-25-Y-G-P269.html

If a sealed lead acid? number 2

Thanks, that's what it's on so I can leave it alone!

 

[friar tuck]

Thanks for the info Tech100 i will get myself one like yours in the meantime ive sent a request for a refund on the other.

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[friar tuck]

Hi update,i complained until blue in the face and managed to get £10 refund on the junk one or send it back to china for a refund.to the £10.my new one arrived today all fitted now but was a pain with the cables.Why make a device to deliver upto 15amps and then put piddly little terminals on? i have 6mm cable and had to thin the ends somewhat to get them to fit.any ways all done just in time for a black sky and rain to arrive ,just before it did i saw 22watts and 1.7amps being generated,at least i know its connected ok. to quote an old morecambe and wise song... bring me sunshine

 

[Techno]

I use these on the right for 6mm rather than those provided on the left

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[Techno]

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[friar tuck]

Hi Andy thanks for that link i ordered some.you say instead of the ones provided? there were none in my package! some piece of kit it is makes the one i bought originally look very mickey mouse. thanks for the recommendation.
would have replied sooner was reading your gas tank install... phew.

 

[Techno]

The ones in the package normally are not very good so you've missed nothing there.