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MG MGB Technical - Trickle charger hook up

I want to put a small trickle charger to the battery to keep it in good condition when not in use.

The car is a late model rubber bumper roadster. Where can I connect it to without having to lift up the battery access panel. What wires are suitable under the bonnet?

Cheers for any advice
AdrianS

Can you not plug it in to the cigar lighter (if you have one)? I do and do!
Michael Beswick

Never checked to see if it was live with the ignition off! I assume the centre contact is positive?
AdrianS

" I assume the centre contact is positive?"

Yes, it is.
Dave O'Neill2

Adrian - I hope that what you have is a battery conditioner (they come under various names - Battery Tender, Battery Buddy, Battery Conditioner, etc.) rather than just a trickle charger. A plain trickle charger will put a continuous charge on the battery and if left in place for long periods of time can over charge the battery and eventually boil off the electrolyte. A battery conditioner on the other hand, will trickle charge the battery to full charge, then turn off, letting the charge drop down to a preset level, at which point it starts charging again. This charge/discharge cycle keeps the battery at a useable level, without overcharging it and also by cycling the battery charge level up and down, it prevent the plates from becoming coated with sulphate. Cheers - Dave
Daved DuBois

Hi Adrian,

I use a solar trickle charger so I remove the fuse that connects the brown circuit to the purple circuit and clip on the charger output across the fuse mounting that is on the brown side of the fuse box, and the engine block. Removing the fuse isolates any clocks, radios etc that draw standby current, thus ensuring the maximum current flows into the battery. Using the cigar lighter is convenient but devices having a residual current drain will still be connected. My solar charger only delivers 11mA so if the radios, clocks etc draw more than this the battery will not charge. Mains powered chargers will be able to deliver more charging current than this so you may not need to isolate the attached devices. Hope this helps.

Richard
Richard Thompson

Thanks for the comments.

I have got a small charger with about a 500mA output which I use for my motorbike over the winter months - just connecting it for a day or so every month to keep the battery topped up. The bike is a big BMW with a reasonable sized battery .It works very well.

Just wanted to use it occasionally on the MG instead of taking the battery cover off and connecting the "proper" charger.
AdrianS

How about the large hot terminal on the starter solenoid?

Herb
Herb Adler

"How about the large hot terminal on the starter solenoid?"

Easy if you have an inertia starter. Not so easy if it's a pre-engaged starter, particularly if it has the cover over the end.
Dave O'Neill2

I have a motorcycle one, works fine on the MGB and TF. With the MkI car its too easy, the brown wire on the solenoid works.
I should fix up a power jack so if I ever forget it just detaches as you drive off, sounds worth doing this on your car.
I just added another charger to the collection Lidl here had them on offer £15 for a sexy one with 6/12v different AH ratings and a recovery mode. Its got a button and lots of LEDs so irresistable :-)
I can now keep both cars floated,
Stan Best

Hi Adrian,

I have a battery tender, which as Dave pointed out doesn't damage the battery. Mine came with the usual croc clips for connecting to the terminals, but also a fused harness that connects to the battery terminals using ring terminations. I do have a single 12 Volt battery, which made it easier, but it would still work with the two battery setup.

The harness has a quick connector that connects to the charging unit output cable. I positioned that inside the car just above the battery panel. All I do when I've finished driving is connect the charger unit and cover the car. I always have a fully charged battery whether I go back to it the next day or weeks later. The connector has a cover when not being used and is barely noticeable.

Definitely worth a look, I would say.

Cheers

Phil
PG Crowell

This thread was discussed between 12/10/2012 and 25/10/2012

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