dc/dc charger

HI CREW, got problems after fitting a dc/dc 20amp charger, I have got 240watts of panels up on canopy in front of roof top tent, the sun this time of year in north qld is more than enough, the panels charge 2 marine batteries, & run 2/40lt engels ,with one on freeze. I went away last year for 3 months to cape York with no use of generator or electricity. this year I put in a dc/dc 20amp charger and had trouble while camped up with solar only, its seems I was not getting enough power through it, I by passed it & hooray im back to normal with no more running of generator. the charger is very simple to wire in, & thought the thing would be great ? the panels have the usual regulator on the back. I havnt named the charger , because I don't know if im aloud to ? cheers
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Reply By: Mick O - Sunday, Sep 29, 2013 at 18:03

Sunday, Sep 29, 2013 at 18:03
Ray, I may be wrong but I would have thought your panels should be connected "Open Circuit" to the dc-dc charger. If you have them patched into the standard (fitted) regulator as well, you will not be maximising the panels output to the charger.

What type of dc-dc charger is it and I'm presuming it has a built in solar regulator (hopefully an MPPT type)? Is the DC-DC charger mounted as close to the batteries as possible?

Cheers Mick
''We knew from the experience of well-known travelers that the
trip would doubtless be attended with much hardship.''
Richard Maurice - 1903

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AnswerID: 518907

Follow Up By: ray t1 - Sunday, Sep 29, 2013 at 18:26

Sunday, Sep 29, 2013 at 18:26
thanks mike, yer wired straight from panel regulator to charger, the charger being ctek, thanks
FollowupID: 798857

Follow Up By: oldtrack123 - Sunday, Sep 29, 2013 at 19:12

Sunday, Sep 29, 2013 at 19:12
HI Ray
If you have the solar connected to the DC /DC charger SOLAR INPUT,you should remove or bypass the solar reg
Just leave the Ctek to do the charging.

Alternatively you could connect the solar reg output direct to the battery PROVIDED neither reg is a MPPT

FollowupID: 798862

Follow Up By: Notso - Sunday, Sep 29, 2013 at 19:36

Sunday, Sep 29, 2013 at 19:36
Yep, I've just done this with mine and the CTek does a much better job of charging the battery than the one supplied with the panel.
FollowupID: 798864

Follow Up By: The Bantam - Sunday, Sep 29, 2013 at 22:40

Sunday, Sep 29, 2013 at 22:40
Ray mate I recon mick has your problem picked in 1.

Ya cant run one regulator after another, the smarter the regs the worse the results.

These regulators are looking for a direct relationship with both the solar panels and the battery. A MPPT reg works by optomising the relationship between the panels and the battery.

If there are two regs, neither can see the whole picture.

These two regs will be looking at each other yellin' " what the hell are you doin' here...what the hell are YOU doin' here.....where is the battery...I'm not tellin'...where the panel..I'm not tellin'.......well not realy but ya get the point..

FollowupID: 798881

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