Solar Trickle Charger - Overcharge Possible?

[Baldchap]

We have a car overseas in a sunny climate that is left with a company when not in use.

12v batteries die and so the obvious solution is an OBD socket solar charger on the dash.

https://www.amazon.co.uk/gp/aw/d/B00AC1LLQY?psc=1&...

My question is, if someone starts the car and drives it with the charger still plugged in, is it likely to damage the battery?

[E-bmw]

No.

[E-bmw]

Post deleted, misread OP thanks for showing me to be an idiot LRR.

Edited by E-bmw on Tuesday 21st October 16:49

[littleredrooster]

E-bmw said:

But don't forget that unless the lighter socket is live when the car is off it will NOT charge anything.

Baldchap said:

...so the obvious solution is an OBD socket solar charger on the dash.

OP - be aware that not all solar panels are voltage-controlled. I use one on the MX-5 exactly as you describe, but - following a tip-off from the owner's club - I measured the battery voltage on a sunny day and was horrified to see 21.6V!! The battery died shortly afterwards...

I wired a voltage-dropper buck into the circuit and set it a maximum of 15V, and also put a bluetooth battery monitor on top of the battery so I can keep an eye on it.

[GreenV8S]

If you're leaving the vehicle unused over the medium/long term then you need a battery maintainer, not a battery charger or a simple current source like a raw solar power supply.

You could power your battery maintainer from a suitable solar power supply, if you have one.

[E-bmw]

littleredrooster said:

E-bmw said:

But don't forget that unless the lighter socket is live when the car is off it will NOT charge anything.

Baldchap said:

...so the obvious solution is an OBD socket solar charger on the dash.

OP - be aware that not all solar panels are voltage-controlled. I use one on the MX-5 exactly as you describe, but - following a tip-off from the owner's club - I measured the battery voltage on a sunny day and was horrified to see 21.6V!! The battery died shortly afterwards...

I wired a voltage-dropper buck into the circuit and set it a maximum of 15V, and also put a bluetooth battery monitor on top of the battery so I can keep an eye on it.

Good points obviously, but as it is sold by the AA for use in a car I would hope it was regulated.

Bluetooth battery monitors are good, but no help if you are in a different country.

[OldGermanHeaps]

The cheap ones are unregulated. Get an mppt regulator like a renogy or victron

[littleredrooster]

E-bmw said:

Good points obviously, but as it is sold by the AA for use in a car I would hope it was regulated.

Mine is exactly the one in the OP's link. It is unregulated, as is the larger, Halfords-branded panel I bought for low-sun conditions in the winter.

...and the ultimate irony is that,having written about it, my buck voltage controller has given up the ghost at some point in the last two days!! Output now = nil.

[Smint]

E-bmw said:

Post deleted, misread OP thanks for showing me to be an idiot LRR.

Edited by E-bmw on Tuesday 21st October 16:49

Glad i'm not the only who does that, some of the gaffes made over the years could kick myself.