Starter battery bodge .... with photos

[RichardS]

I've written on here before that my starter batteries (and the house batteries for that matter) have been in use for 11 years and that I suspected that they were on borrowed time but that replacing them with starter batteries with the same terminal layout looked like it was going to be problematic as I need an M10 threaded +ve terminal and an M8 threaded -ve terminal.

Anyway, the batteries finally failed last month so it was time to bite the bullet.

The nearest I could find at a reasonable price (i.e. less than £500!) were from Tayna. These batteries have both threaded terminals, which Tayna seem to think are M10 although I discovered when they arrived that they are actually a 10mm-ish imperial size, although that doesn't matter.

Anyway, I needed to bodge a way of getting the 8mm negative rings terminals onto the 10mm negative post.

With a strip of pure copper, a drill and an 8mm tap, a solution presented itself:

Bodger heaven here I come! :encouragement:

Richard

 

[Dave100456]

Don't understand... Can't see evidence of use of a tap, pls explain.

 

[VicS]

Don't understand... Can't see evidence of use of a tap, pls explain.

I imagine the 8mm terminal consists of an 8mm set screw threaded into a tapped hole in the copper bar.

My solution to the same problem would probably have been a clamp to fit the round post with an 8mm stud terminal because I don't have the copper bar

or possibly to have bought a battery with just round posts, if possible, and used a pair of clamps with stud terminals The positive one with a 10mm stud and the negative with an 8mm stud

 

[lw395]

I imagine the 8mm terminal consists of an 8mm set screw threaded into a tapped hole in the copper bar.

My solution to the same problem would probably have been a clamp to fit the round post with an 8mm stud terminal because I don't have the copper bar

or possibly to have bought a battery with just round posts, if possible, and used a pair of clamps with stud terminals The positive one with a 10mm stud and the negative with an 8mm stud

Or just put the ring terminal under the nut of the clamp bolt of any battery clamp.

 

[Dave100456]

I imagine the 8mm terminal consists of an 8mm set screw threaded into a tapped hole in the copper bar.

My solution to the same problem would probably have been a clamp to fit the round post with an 8mm stud terminal because I don't have the copper bar

or possibly to have bought a battery with just round posts, if possible, and used a pair of clamps with stud terminals The positive one with a 10mm stud and the negative with an 8mm stud

Vic, Surely if the copper bar has been tapped then it wouldn't screw down onto the 10mm negative set screw as the principle battery post would stop it rotating.

However, I'm still baffled by the original poster's use of a "tap" on the 8mm and perhaps we'll get an explanation today.

 

[VicS]

Vic, Surely if the copper bar has been tapped then it wouldn't screw down onto the 10mm negative set screw as the principle battery post would stop it rotating.

However, I'm still baffled by the original poster's use of a "tap" on the 8mm and perhaps we'll get an explanation today.

I did not suggest that the copper bar had been tapped to screw on to the 10mm stud............. Any fool can see that the round post would prevent that

I suggested what the 8mm tap had been used for... To tap a hole in the copper bar for an 8mm set screw to form the new 8mm stud.

 

[PaulRainbow]

Vic, Surely if the copper bar has been tapped then it wouldn't screw down onto the 10mm negative set screw as the principle battery post would stop it rotating.

However, I'm still baffled by the original poster's use of a "tap" on the 8mm and perhaps we'll get an explanation today.

Simple, as Vic already explained. The 10mm battery fitting is a 10mm hole. The 8mm stud for the 8mm battery cables is a hole, threaded with an 8mm tap, with a machine screw/set screw threaded in from underneath before fitting the copper strip to the battery. This leaves an 8mm stud to connect the battery cables to.

 

[RIBW]

Hi,
Could someone clarify things for me? When I see 'Marine' (as in Exide Marine and Multifit) on a battery, doesn't that mean the threaded post are 3/8" and 5/16" ? It did on the last threaded battery I replaced.
Cheers
Bob

 

[PaulRainbow]

Hi,
Could someone clarify things for me? When I see 'Marine' (as in Exide Marine and Multifit) on a battery, doesn't that mean the threaded post are 3/8" and 5/16" ? It did on the last threaded battery I replaced.
Cheers
Bob

I've had UNF and metric threads on batteries, seems to depend on the make.

 

[RIBW]

Paul,
Thanks. It looks like my continuing thread caution is justified.
Cheers
Bob

 

[RichardS]

I imagine the 8mm terminal consists of an 8mm set screw threaded into a tapped hole in the copper bar.

That's right. I could get an open ended 13mm spanner under the bar but it seemed easier to tap a thread into the copper so fewer tools needed when connecting up.

Richard

 

[RichardS]

Or just put the ring terminal under the nut of the clamp bolt of any battery clamp.

The problem is that I would need to twist the thick starter cable by 90 degrees which I'd rather avoid, and I'm not sure whether you can buy those clamps with M10 bolts so the ring terminals would not fit snugly.

Richard

 

[pvb]

That's right. I could get an open ended 13mm spanner under the bar but it seemed easier to tap a thread into the copper so fewer tools needed when connecting up.

Wouldn't it have been easier just to crimp a 10mm ring terminal on the negative cable?

 

[RichardS]

Wouldn't it have been easier just to crimp a 10mm ring terminal on the negative cable?

There are 3 or 4 cables connecting to that terminal and at the moment they all have 8mm rings. My crimper would be powerful enough for the smaller cables but I'd never be able to crimp the heavy duty starter cable without buying a better crimper.

Richard

 

[RichardS]

Hi,
Could someone clarify things for me? When I see 'Marine' (as in Exide Marine and Multifit) on a battery, doesn't that mean the threaded post are 3/8" and 5/16" ? It did on the last threaded battery I replaced.
Cheers
Bob

That's a very astute observation Bob.

I wasn't sure what studs I was actually going to get and couldn't see the information on the Tayna website but when the batteries arrived, the studs were covered but there were two nuts in the little plastic bag you can see in the photo. One nut was clearly 10mm-ish and the other was 8mm-ish.

I thought, "Great, just what I needed" .... but when I removed the plastic covers both the threaded terminals were 10mm (actually 3/8 as I found when I started to investigate if I had a spare 10mm nut in the garage that I could use).

I emailed Tanya to ask if I was missing something as the smaller nut didn't appear to fit so, with 2 batteries, I was 2 larger nuts missing.

Tanya emailed me back and also phoned me within 24 hours (very good service) to say that they had checked all the batteries in their stock and they all came with a large nut and a small nut. Tanya think that the large nut is an M10 but it isn't but that's a detail.

They had contacted Exide to find out what was going on and Exide apparently explained that they have changed the terminals on the battery but the guy in the Nut Attachment Department had not been told so was still sending the batteries out with a small nut. :ambivalence:

Two large nuts arrived in the post the next morning so all's well that ends well, except that anyone currently using these batteries who now replaces them on a like-for-like basis is going to face exactly the same problem as me, although I think that the Furneax Riddell terminals that Vic has linked to are an excellent choice which I intend to investigate further.

Richard

 

[RIBW]

.... anyone currently using these batteries who now replaces them on a like-for-like basis is going to face exactly the same problem as me, although I think that the Furneax Riddell terminals that Vic has linked to are an excellent choice which I intend to investigate further....
Richard

Richard,
Thanks for that explanation - as I've said on previous postings - thank goodness there is not the same confusion over volts and amps as there is over threads (talking DC that is)!
Cheers
Bob

 

[PaulRainbow]

I think that the Furneax Riddell terminals that Vic has linked to are an excellent choice which I intend to investigate further.

I've used lots of those on batteries that don't have the stud fixings, they work fine. If i fit batteries with stud fixing though i remove them, one less connection to worry about. I wouldn't be able to spend the time it took to make your copper strips, labour cost would exceed the cost of the clamps, i guess you used what you had to hand and you didn't have to pay yourself for the time However, seems to me that they serve the purpose and i can't see any benefit in changing to the clamp types.

You mention that there are a few cables going to each battery, so it might be worth fitting a small busbar or battery post, and connecting the 8mm connections to that, with a short cable (10mm connection one end, 8mm the other) between the battery and busbar/post ? If that sounds appealing and your crimper isn't big enough, i could make a pair of cables up and post them to you for the cost of the materials and post.

 

[RichardS]

I've used lots of those on batteries that don't have the stud fixings, they work fine. If i fit batteries with stud fixing though i remove them, one less connection to worry about. I wouldn't be able to spend the time it took to make your copper strips, labour cost would exceed the cost of the clamps, i guess you used what you had to hand and you didn't have to pay yourself for the time However, seems to me that they serve the purpose and i can't see any benefit in changing to the clamp types.

You mention that there are a few cables going to each battery, so it might be worth fitting a small busbar or battery post, and connecting the 8mm connections to that, with a short cable (10mm connection one end, 8mm the other) between the battery and busbar/post ? If that sounds appealing and your crimper isn't big enough, i could make a pair of cables up and post them to you for the cost of the materials and post.

That's a very kind offer Paul .... I'll give it a try with what I've got once I'm back on the boat but if something doesn't look quite right I might well take you up on it.

Whilst you're here can I ask a question ..... the AGM batteries in the photo appear to have filler caps. I've never seen AGMs like that and the 3 Exide house AGMs which I ordered at the same time don't have anything similar. Are they filler caps? What happens if I put a socket on then and unscrew them?

Richard

 

[PaulRainbow]

That's a very kind offer Paul .... I'll give it a try with what I've got once I'm back on the boat but if something doesn't look quite right I might well take you up on it.

Whilst you're here can I ask a question ..... the AGM batteries in the photo appear to have filler caps. I've never seen AGMs like that and the 3 Exide house AGMs which I ordered at the same time don't have anything similar. Are they filler caps? What happens if I put a socket on then and unscrew them?

Richard

You can't top them up Richard and it's not a good idea to even unscrew them.

 

[pvb]

.... the AGM batteries in the photo appear to have filler caps. I've never seen AGMs like that and the 3 Exide house AGMs which I ordered at the same time don't have anything similar. Are they filler caps? What happens if I put a socket on then and unscrew them?

Are they perhaps the over-pressure valves? I'd leave them alone.

Incidentally, those EM1100 batteries are hugely expensive. Do you need 925A CCA? You could have got the Exide EP800 AGM with 850A CCA for about half as much.