36 replies to this topic

[beardylondon]

Love to see a photo of this!

 

What I usually do is to mount a rear exhaust 'cotton-reel' fitting under the bonnet bolted through the bulkhead or inner wing. I connect the main battery feed to the threaded stub, which is insulated by the rubber in the mounting. That gives a good power source to feed to additional fuse boxes without attaching to the starter solenoid. I put a rubber cap onto the live stub and when i need to charge the battery I just have to open the bonnet and take off the rubber cap.

The advantage is that crimp-on ring terminals can be used to take power to fuse boxes and the cable lengths are relatively short and look tidy.

[Cooperman]

I'll try to get one shortly.

I always do this and have done so for years. Nowadays you find a similar arrangement on modern cars. My BMW has a 12v terminal covered with a red plastic shield in the engine bay.

Because I run a lot of auxiliary electrical feeds on my rally cars, I find that this power source in the engine bay is ideal. All the power feeds to the 3 fuse boxes for the spot & fog lights, the manually-operated aux fan, the navigator inst panel inc clocks, the 2nd fuel pump, reversing light, heated screen, map lights, sidelights and headlight feeds all run from this live terminal which I think makes it a better arrangement than everything coming off of the solenoid terminal.

I got the idea from an aerospace electrical design engineer who, years ago, helped me with the wiring of a Cooper 'S' rally car. He felt that using the solenoid terminal as a master supply point was a 'weak point' in the electrical system.

Thus the power goes from the battery to the FIA master switch which is between the front seats and then to the master live terminal under the bonnet. That wiring is very well insulated and shielded from possible damage.

[croc7]

I carry a lot of stuff in the boot plus the boot board to wrestle out between the two tanks.  A pain in the ___.

Sort of designing a solution for a problem that doesn’t exist, even with a boot liner it’s 20 seconds to connect a battery charger up.

[croc7]

What I should have noted in the original post was that I was not going to use the large, clunky charger that I have but rather would use one of the smaller compact ones that are more handy to use.  The parking situation in my garage is such that connecting to a 12V source in the engine compartment would offer better access to the wall socket for the trickle charger.  Probably go with a CTEK or a NOCO unit and hardwire to the battery terminals although the muffler cotton reel mount idea is appealing. Thanks for all of the replies.

[gazza82]

You can also get a 2.5m CTEK extension lead!

[croc7]

Didn't know that, thanks!

You can also get a 2.5m CTEK extension lead!

[croc7]

As i'm limited for space with both mini's in the garage, i have the CTEK ring terminals attached to the alternator post and one on the slam panel. No error messages on the charger.

I didn’t realize that the alternator had a post, checked mine and found that it has a post that is hot all of the time. Looks like a promising location to attach a battery trickle charger but I’m not an automotive electrician and am curious if using that post could potentially damage the alternator/charging system. Thoughts?

[Dusky]

So why would you pick the alternator connection over the starter lug?

[croc7]

If you’re referring to the battery lug on the starter solenoid, I think putting the trickle charger’s eyelets at the left side of the engine compartment would be a cleaner installation. Although I am looking at the starter solenoid location and running the wires forward along the existing loom.

Edited by croc7, 07 November 2021 - 04:28 AM.

[croc7]

As i'm limited for space with both mini's in the garage, i have the CTEK ring terminals attached to the alternator post and one on the slam panel. No error messages on the charger.

I didn’t realize that the alternator had a post, checked mine and found that it has a post that is hot all of the time. Looks like a promising location to attach a battery trickle charger but I’m not an automotive electrician and am curious if using that post could potentially damage the alternator/charging system. Thoughts?

Any auto electricians out there who care to comment?

[Steve220]

 

As i'm limited for space with both mini's in the garage, i have the CTEK ring terminals attached to the alternator post and one on the slam panel. No error messages on the charger.

I didn’t realize that the alternator had a post, checked mine and found that it has a post that is hot all of the time. Looks like a promising location to attach a battery trickle charger but I’m not an automotive electrician and am curious if using that post could potentially damage the alternator/charging system. Thoughts?

 

It's the cable the alternator uses to power the system. The CTEK follows similar charging principles. But to answer your query, wherever you put the charger, it would have the same impact on the alternator as its an integral part of the car's electrical system.

[croc7]

 

 

As i'm limited for space with both mini's in the garage, i have the CTEK ring terminals attached to the alternator post and one on the slam panel. No error messages on the charger.

I didn’t realize that the alternator had a post, checked mine and found that it has a post that is hot all of the time. Looks like a promising location to attach a battery trickle charger but I’m not an automotive electrician and am curious if using that post could potentially damage the alternator/charging system. Thoughts?

 

It's the cable the alternator uses to power the system. The CTEK follows similar charging principles. But to answer your query, wherever you put the charger, it would have the same impact on the alternator as its an integral part of the car's electrical system.

 

Hmm, my alternator has a multi plug and the post that I referred to is at the approx 6 o'clock position and has no cable attached at all.  No idea what purpose it serves.

[unburntfuelinthemorning]

I got the idea from an aerospace electrical design engineer who, years ago, helped me with the wiring of a Cooper 'S' rally car. He felt that using the solenoid terminal as a master supply point was a 'weak point' in the electrical system.

What was your friend's reasoning to consider the use of the solenoid terminal as a master supply point a weak point in the electrical system?

[Cooperman]

I don't know the reason for his comment. Maybe his reasoning was the fact that on a rally car there are a lot of extra components abd a dedicated additional main supply terminal near the fuse box area would be best.

However, his wiring has proved excellent and totally reliable and I have copied his approach with other cars.

[beardylondon]

Going back to this, I am going to buy the below lead and permanently connect it in the engine bay for easy trickle charging, as the way my cars are parked in the garage, it is easier to access the front etc etc.

 

https://www.mdsbatte...yelet-lead.html

 

So am I best off attaching it to the starter motor?

 

Any tips and tricks much appreciated!