Mppt Regulator

[atcmatt]

Hi there. I recently purchased an 80w canvas folding solar panel. In regards to the regulator that it comes with. I have 19.9 volts coming out of the solar panel. I also have 19.9 volts coming out after the regulator. Is this normal or should it be putting out around 14.4 after the regulator? When it is connected to an almost full battery the lights rotate on and off quickly and the battery voltage (with a multimeter connected) fluctuates from as high as 14.5v right down to 12.8 in conjunction with the lights. Is this a normal occurance or do I have a faulty regulator? Thanks. Matt.

 

[jonney]

sounds like the reg isn,t working atyall. 19.9 volts at panels, the reg should drop the output voltage to no more than 14 odd volts max.

 

[happy john]

Matt, sounds abnormal though most of these panels on the market have shit regulators and wireing too thin to carry the power. I would bypass the regulator and with thicker wire depending on the length let your C/Tek look after the regulation via it's solar input.
Cheers

 

[atcmatt]

Thanks for the replies. I contacted narva (projecta) today and the bloke told me that it is normal for the regulator to show the same open circuit voltage when it is not connected to a battery. Once it is connected that's when the magic happens and the voltage drops. I generally do run it through my ctek mainly but I also want to use it for a second 80ah battery in a pack that I carry as a backup for charging lights and torches etc. looks like we are all good. So much to learn when it comes to all this 12v gear but it's all very interesting. Thanks again.

Matt

 

[jonney]

so the regulator just regulates the voltage keeping it at the same 19 odd volts until the connection is made to the battery, then i would think around 12 volts of battery power would be supplied.

 

[atcmatt]

Yeah pretty much. It will put out about 14.4 in full sun he said.

 

[Old.Tony]

14.4V is fine for flooded cell or AGM, but not for Gel. It will make the electrolyte fizz lightly, but in a Gel battery that's enough to destroy it.

I've never measured the open circuit output of my own regulator. I have a PWM (cheap) regulator and a MPPT (good) and might check both when I am next thinking about it.