Solar Battery Charging

[wfe1947]

Just bought a cheap solar panel from Maplins with crocodile clips for connecting to batery.

Can I connect the solar charger to the 12v terminals on the outboard as this seems the easiest thing to do?

Otherwise how do I connnect it?

Do I need a regulator?

any advice would be appreciated.

 

[rob2]

Can't answer without asking a few questions... What size is your battery? What output is the solar panel? Does the panel have diodes to prevent reverse flow?

Actually the third is the first to ascertain as without diodesyour battery will discharge overnoght through the panel! If you end up with a regulator, these often include blocking diodes.

Normally the recommendation is that the output of the panel should not exceed 10% of the capacity of the battery unless a regulator is fitted. Below 10% the panel will only provide a trickle charge, so it's not a problem. Higher outputs can charge the battery too fast and cause outgassing - a regulator will keep the charge rate at an acceptable level.

The really cheap, small panels I've seen in Maplins and autofactors are only intended to match the self discharge of a car battery, so will not cause you a problem but will not recharge the battery either.

Rob.

 

[pappaecho]

assuming the panel is small the output will be sufficiently low as not to need a solar regulator. I think that all Maplin panels have an inbuilt " blocking diode", which prevents reverse discharge.

As the current flow will be low I suggest that the crocodile clips are connected directly to the battery posts, to prevent losses

 

[VicS]

Its difficult to understand why connecting to the outboard will be easier than connecting directly to the battery but if it is, it is !
Id try to make the connections directly to the battery if possible.

However you do it, make sure that the connection(s) to the battery are properly fused with a fuse that reflects the wire sizes used.
It may be necessary to fit a fuse in the connection to the solar panel as well as the one in the wiring for the outboard if the solar panel wiring is light.

rob2 is right about the need or lack of need for a regulator. If you have less than 1 watt of solar power per 10Ah of battery capacity you do not need a regulator although it is recommended that solar panels over 10 watts should have a regulator anyway.