Maintenance charger over the winter

outfox

Hi all
Despite all the advice plastered all over the web about connecting the negative clip to the body frame rather than the negative terminal of the battery, I went ahead and connected it to the battery directly. This is because the charger manual recommended this, surprisingly. The expert in my local battery dealer also said it would be fine to connect to the battery directly.

Does any one else connect directly to the battery? To complicate things, the battery is in the boot of the car, and I can't leave the boot lid open in its current garage.

The car is off the road for the winter, and I'm starting to think there's going to be one hell of a bang.

Del2005

Why not just remove the battery and charge it indoors. FWIW I've a trickle charger hard wired to my bikes battery, that's how the instructions said to do it.

w124man

This is a serious post, yeah?

outfox

Unfortunately, yes. My garage is unavailable at the moment, and I've temporary storage arranged. I don't know how secure it is, so don't want to leave the boot lid open in case the battery is whipped.
I'd also prefer not to remove the battery, as the electronics could go haywire. Battery removal was the simplest option on the older Mercs that I had, but I'd be worried that the car might be plagued by electronic gremlins if the battery was removed for a few months. I'm also convinced that cars deteriorate a lot faster when the battery is removed, although maybe this is my imagination.
I'm not sure what the best way around this is. The storage is not readily accessible, so calling in and out at intervals to connect a charger is not an option.

w124man

My R129 has a CTEK battery charger attached to it with just the mains lead hanging out of the boot and the boot locked. Whoever told you about connecting the negative clip to the body frame rather than the negative terminal of the battery is yanking your chain. Of course the charger manual recommended it, unsurprisingly.

outfox

OK, that's a relief, thanks. When opening your boot after a spell, did you ever get a whiff of any gas from the battery?

w124man

outfox wrote: »

OK, that's a relief, thanks. When opening your boot after a spell, did you ever get a whiff of any gas from the battery?

Nope!

SCOOP 64

ive always connected the nagative clip to battery terminal when jump starting never had any problems, maybe just been lucky over the years.

outfox

I used to do that too, but got the impression from reading online that direct connection to the negative terminal is a no no when jump starting. I think it's less of an issue during maintenance charging as there is less off-gassing. But everyone I know connects directly to the negative terminal.

Tazio

My classic car has a battery cut off switch so the battery stays in the car (in the boot). I use a battery (trickle) conditioner and connect directly to the battery terminals. The conditioner / charger will attempt to bring the battery voltage up to it's predetermined value - if you connect -ve to chassis etc you're adding in this loss .. well in my mind anyway.

Cheers
T

outfox

Tazio wrote: »

if you connect -ve to chassis etc you're adding in this loss .. well in my mind anyway.
T

That makes sense actually.

w124man

outfox wrote: »

but got the impression from reading online that direct connection to the negative terminal is a no no when jump starting.

Im curious to know where you are getting this from

Draig

w124man wrote: »

Im curious to know where you are getting this from

I always thought it was to prevent sparks around the battery in case there were fumes there.

Esel

Draig wrote: »

I always thought it was to prevent sparks around the battery in case there were fumes there.

Yeah, it's recommended for that reason.

outfox

w124man wrote: »

Im curious to know where you are getting this from

A lot of online articles state it. eg.

https://www.halfords.ie/advice/motoring/how-to-guides/how-to-jump-start-a-car-guide-video

w124man

Draig wrote: »

I always thought it was to prevent sparks around the battery in case there were fumes there.

Why on earth would you connect a live battery charger to a battery? Connect first and then switch on, its basic stuff! There are obviously better idiots out there these days which must why there are instructions on shampoo bottles!

Dades

Obviously I'm going to have to rethink the way I connect my battery charger when I pull the battery.

And the way I shampoo my hair.

Draig

w124man wrote: »

Why on earth would you connect a live battery charger to a battery? Connect first and then switch on, its basic stuff! There are obviously better idiots out there these days which must why there are instructions on shampoo bottles!

Obviously.but the question I was answering was about when jump starting.

Tails142

The reason has been mentioned in a couple of other posts, positive red terminal gets connected first then the black negative. When connecting the negative there can tend to be a spark especially if there is an active draw, charging batteries emit hydrogen which is extremely flammable, think of the Hindenburg. The advice is to connect the negative to the chassis, reducing the chance of a spark near to the battery which could cause it to explode. Batteries exploding into people's faces is the main risk when jump starting cars.

w124man

Tails142 wrote: »

charging batteries emit hydrogen which is extremely flammable, Batteries exploding into people's faces is the main risk when jump starting cars.

Jumping cars is not the same as charging. Sealed batteries tend not to emit hydrogen dont you think? Ive been jumping cars for well over 50 years and never heard of one exploding!