Home build or buy more product?

[Mr Gus]

Lost a battery the other day (12v for the leaf due to intermittent time on the road)
Should I buy an off the shelf version of a solar battery charger?

Thought i'd put one in the smart & one in the leaf.

If so recommendations for ones that aren't merely expensive crap please.
Or employ 2 old 10 watt yingli panels & cobble something together?

The Smart has the battery in the cabin under the carpet so is in theory simple to add another (3rd cable) to, it already has a clip for attachment of a CTEK charger so would prefer to be able to hook up to that.

[Stinsy]

To be useful you want something in the 20-30W range and that’d have to be A3 ish in size. Then you need direct sunshine…

Easier and more like to be effective if you buy a proper mains charger and apply that a few times a year…

I have one of these: Maypole M730 20 A Metal Battery Charger 12/24 V https://amzn.eu/d/j3YDuIX

[Mr Gus]

I have several cteks but a lousy brain, so whilst I tend to desulph & charge the batteries every year this is a necessary evil (it also grates that these would be stuck behind glass, but you cannot win em all)

[robl]

I think a PV panel much over 5W will need a voltage regulator after it. Otherwise if it’s in direct sunlight for too long you might kill the battery by overvolts. I usually leave a 10W panel on the parcel shelf of our barely used mondeo, to keep the battery topped up. It’s got a 12v linear reg with 3 series diodes in the 0v line, so it limits at 13.8V.
‘Interestingly’ the mondeo cigarette lighter socket disconnects an hour or so after the car is locked. Took me some time to figure out what was going on there!

[Mr Gus]

Some have a connection via the OBD port Robi, would that help your Mondeo out any do you think?

[Windbag]

‘Interestingly’ the mondeo cigarette lighter socket disconnects an hour or so after the car is locked. Took me some time to figure out what was going on there!

I now have a tranny* in back of the new truck, 'cos everything goes dead after 10 mins.

* not that

[Windbag]

Lost a battery the other day (12v for the leaf due to intermittent time on the road)
Should I buy an off the shelf version of a solar battery charger?

Thought i'd put one in the smart & one in the leaf.

If so recommendations for ones that aren't merely expensive crap please.
Or employ 2 old 10 watt yingli panels & cobble something together?

The Smart has the battery in the cabin under the carpet so is in theory simple to add another (3rd cable) to, it already has a clip for attachment of a CTEK charger so would prefer to be able to hook up to that.

I vote CTEK... Not the basic one, but the one with the recovery option

Option.

[Mr Gus]

Yeah, that's what i've had for years, but plug access is terrible (like my memory)

Which is why i'm wading through the godawful seller CS of Ali-express where a listing fails to state (regularly) what silicon type is used, often stating BOTH within a listing (& i'm hardly observant) takes several days & multiple messages to get beyond a "guess" reply from a crap seller

As per many modern vehicles all systems are pretty much off when key not present, dead cigarette socket, so info as to whether the panel has a blocker diode or the cig adapter is vital (and missing) ..thus me thinking make one / several, but depending on car size (such as the smart) you don't necessarily want that wallowing around in your cars.

[Windbag]

I sort of fudged it.

If you have a 13 pin tow plug, the is a permanent 12v (also one in the white plug)

Easy adapter to make 13pin>fag lighter and run the wire back into the boot, chargers, phones cooler etc.

You could do the same for the CTEK.

[Mr Gus]

Ah hell, more research!

One is for the leaf the other is for the Smart 450 which is a bit of a low mileage classic the OBD is temepremental as hell potentially & expensive to replace if screwed up, (long story) unless you are referring to a permanently live fuse to piggyback?