Page 1 of 1

Solar panel for motorcycle battery

Posted: 09 Feb 2020, 13:11
by maxstu
I require a solar panel to keep my motorcycle battery in good order, when stored in cold garage. The battery will stay connected to bike and is 12 Volt 8.6 AH CCA 190.
Can l use a car dash solar panel and replace with croc clips instead of cigar lighter terminal? Never thought much of these for car use. How can it possibly get charge to battery through an OUTLET?
Also does panel need to face sun? I can attach it to interior of window. But not on sunny side. I can mount externally to metal garage door. However this door gets very hot with direct sunshine in summer.
Whats the consequence of extending cable from panel to battery? Distance is approx 4 metres.
Will it harm battery and what spec should l consider?
Many thanks
Stuart

Re: Solar panel for motorcycle battery

Posted: 09 Feb 2020, 22:48
by slowcoach
Outlet, inlet, no such thing, it's Only access to the battery via the same cables.

With such a small battery, it's a case of whether or not the panel would need a charge controller to siphon off any excess power, to avoid damaging the small battery- which I don't know. It'd only be a small panel you'd need though. It Doesn't need direct sun to maintain a battery, only to give it max charge. I doubt a 15w panel would harm it, But you'd want to monitor the battery for a period (couple of weeks), before you left it unattended for any length of time.
Or get a cheap charge controller aswell, to be on the safe side..

Re: Solar panel for motorcycle battery

Posted: 09 Feb 2020, 23:30
by maxstu
Hello Slowcoach,
And thanks for your views. I can keep an eye on panel as you suggest. Will source a 15w and convert to crocodile clips to connect direct to battery.
In your view will extending cable reduce power to battery? May be a good thing.
Regards
Stuart

Re: Solar panel for motorcycle battery

Posted: 10 Feb 2020, 08:03
by slowcoach
I wouldn't worry about cable length, 4 metres is fine, just use a similar or bigger gauge wire than on it now ;)

Re: Solar panel for motorcycle battery

Posted: 10 Feb 2020, 08:30
by 937carrera
15W max output is only a charging rate of just over 1 amp, that's a trickle in my book as a phone charger is between 0.5 and 2 amps.

Have you ever put a voltmeter on your solar panel, you might find that it barely gives enough to put a charge in at this time of year, and even then for less than 8 hours a day.

Daft thing is my scooter battery is knackered due to being drained. My little solar panels, which came with crocodile clips, were sat on the shelf. I made the assumption that there was no drain when the ignition was off. Maybe that was a valid assumption but I still need to buy a new battery.

Re: Solar panel for motorcycle battery

Posted: 10 Feb 2020, 11:02
by maxstu
Thanks to both.
Carrera, if your scooter has modern inbuilt security or immobiliser/alarm it will drain battery. Even a little flashing light is enough.
My previous bike, a 2008 GSF650 had no such electronics and could be left for a month without issue. Whereas my replacement Honda has the HISS security and will drain down in two weeks without use.
Its merely to keep battery at starting level and not for charging.
I understand l should buy system with a non-return diode? Otherwise if connected overnight it reverses and may drain battery?

Re: Solar panel for motorcycle battery

Posted: 10 Feb 2020, 11:10
by maxstu
Btw. What are the connectors called that share the same molded housing for a live and an earth wires. One side is an exposed bullet and the other side takes exposed bullet?
Apologies for my cryptic description. :shock:

Regards
Stuart

Re: Solar panel for motorcycle battery

Posted: 10 Feb 2020, 13:12
by Oldiebut goodie
Anderson?

Re: Solar panel for motorcycle battery

Posted: 10 Feb 2020, 13:44
by 937carrera
There's a bit big for one of those solar panels, good too.

I don't know what they are called either, I suspect Stu has a panel like this one https://www.ebay.co.uk/itm/Car-Solar-Pa ... 3827934615 and he just needs the croc bit to connect to instead of the lighter socket.

My scooter has a metal / plastic key, no immo, I just shouldn't have left it so long, either that or I left a light on, probably the former

On the diodes, this explains things well, https://www.solar-facts.com/panels/panel-diodes.php, but I haven't worked out how the electrical energy being taken from the battery has been consumed, unless the solar panel ends up radiating heat ???

Re: Solar panel for motorcycle battery

Posted: 10 Feb 2020, 13:48
by 937carrera
How about an S-S connector ??

https://www.ebay.co.uk/itm/Crocodile-Cl ... 4423179474

Buy a panel, get one free :rollin

Re: Solar panel for motorcycle battery

Posted: 11 Feb 2020, 09:52
by maxstu
937carrera wrote:How about an S-S connector ??

https://www.ebay.co.uk/itm/Crocodile-Cl ... 4423179474

Buy a panel, get one free :rollin

That's the one. Thanks. This looks suitable?

https://www.ebay.co.uk/itm/10w-Solar-Pa ... %7Ciid%3A1" onclick="window.open(this.href);return false;

Re: Solar panel for motorcycle battery

Posted: 11 Feb 2020, 11:05
by 937carrera
Looks OK, doesn't have the s-s connector so this would just be as a separate charger then

Re: Solar panel for motorcycle battery

Posted: 11 Feb 2020, 15:42
by maxstu
True. I intend fit permanent terminals on bike battery ending with a short bit of cable with s-s terminal peeking out of side panel. Then just plug in when bike goes inside garage. :ok