12v or 24v Solar Panels?

[bridgedino]

Looking to fit a Victron 215w solar panel onto my MH roof. Plugged into a Victron 100/30 mppt controller, and possibly add a 2nd identical panel later on. However the panel im looking at states is a 24v panel and not 12v

Whats the difference between a 12v and a 24v when it comes to MH solar use? Thanks

 

[berni109]

The voltage is taken care of by the regulator usually panels are higher voltage check regulator spec to find max volts it can handle.

Connect battery first so controller knows it needs to work at 12v

 

[jongood]

Looking to fit a Victron 215w solar panel onto my MH roof. Plugged into a Victron 100/30 mppt controller, and possibly add a 2nd identical panel later on. However the panel im looking at states is a 24v panel and not 12v

Whats the difference between a 12v and a 24v when it comes to MH solar use? Thanks

Smaller cables at higher voltages

 

[funflair]

Assuming its the open circuit voltage 24v would be pretty normal for a panel to charge 12v battery, either way though your 100/30 will handle the voltage no problem and as Jon says you can get away with smaller diameter cables or the same and less voltage drop.

 

[Lenny HB]

A12v panel has an output voltage of up to 22 volts, a 24v panel up to 46 volts.

24v panels are used on domestic house installations no reason not to use them on a van just need to make sure houcontroller can handle the higher voltage as Jon says you can use smaller cables with a 24v one.

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[bridgedino]

Thanks guys

 

[weefish]

Depends how much roof space you have and the capabilities of your solar controller. I run a 300w 40v panel with a victron 100/20 controller. 600-700wh over the past few days.

 

[autorouter]

Whats the difference between a 12v and a 24v when it comes to MH solar use?

If using a PWM solar controller it's important. A 24V panel with a PWM controller may or may not be OK for a 12V battery, some are, some aren't. A 12V panel will be OK with a PWM controller for a 12V battery, but won't be able to charge a 24V battery.

Having said that, since you have a Victron MPPT controller a 24V panel will work fine for either a 12V or 24V battery. Just be sure to connect the battery first. The controller needs to recognise the battery voltage before the solar panel is connected.

 

[Off da Grid]

More volts less drop in power theoretically.
I’ve got a solar farm panel on my van.
37v 255w panel, votronic 350 duo mppt charging 12v.batteries

 

[bridgedino]

Just searched through older threads however I just bamboozles me with the various replies regarding which is better, aluminium angle, screwed to solar panel frame and sikaflex to MH roof or making use of the white plastic corner frame sets you can get. Got 2 tubes of sika 522 plus a tin of activator 205 to clean and prep first before sticking. Aluminium seems to give a bigger footprint of sika on the roof but then I believe some sikas adhere better to plastic than metal Anyone point me in the right direction

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[chrisandbev]

hi if you use aluminum angle its better to put a few 3mm tile spacers onto the sikaflex so that all the mastic does not get pushed out when you stick the panel down

 

[Al n Val]

i’ve 2 sets of lower profile but heavy section corner mounts with centre section pieces bought from salons batteries which I didn’t use, white in colour if your interested

If not i’ll put them on the classifieds next week after my op

cheers and btw im using the same Victron 24v panels and controller and can’t fault them

Al

 

[bridgedino]

Requested assistance from Sika regarding which products to use when sticking solar panels onto grp roof using anodised aluminium angle. Just heard back from Sika and thought i would share. They suggest using sikaflex 552 and the following process

Anodised aluminium – SikaPrimer-207
GRP Roof – Light abrasion with scotch brite pad then Sika Aktivator-205

To ensure the minimum bond line is achieved I would recommend that you use 3-4mm rubber type spacers.