MG
The Classic Marque

Tim --- Just hook your battery charger up to it, that'll do the job---------
On Transit vans doing gear/clutch bleeding/learning and reprogramming they have to have the headlights turned on for some reason as part of the process (possibly to prevent voltage spikes-?) and need a charger hooked up to eliminate any disruptions to the programming procedure.
Most important to have your battery ...

https://www.polybush.co.uk/about-us/our-grades-explained/ gives 90 Shore A hardness for the machinable material.

Richard,

I would expect it would benefit from being held in a collet or soft jaws machined to suit the diameter to near fully support the OD and a sharp tool. I'm machining some wood at the moment and wanted minimal marking so 3D printed some jaw covers to suit the intended diameter and contact about 70% of the OD. I've machined acetal before now and that benefited from being held in a co...

David
I have contacted them with some pics and asked why they failed - especially as the original rubber lasted 30 years ! (not modern rubbish stuff !)

How would you hold the poly bar in the lathe being jelly like ! Also what tools / speeds ?

I have not had it happen but have heard of jump packs blowing (even expensive ones) if the battery is completely flat. Most, even the cheap ones now seem to have something in the lead that blows to protect the pack.

Guy like you I havent used mine on my cars but have impressed a couple of people at work with it. One didnt believe something that small would work when I produced it, but when ...

Polybush do machinable polyurethane bar https://www.polybush.co.uk/advice-blog/machinable-polyurethane-bar/ and https://www.polybush.co.uk/product/pa00-machinable-poly-bar/

Opens some possibilities for those of us with a lathe.

Richard
Well I'll give the smart charger a go - they attempt to de-sulfate the battery I think. I'm still chasing a parasitic drain which might be intermittent. (Not the alarm which can be a culprit). Might be the towbar module or "GROM" module (ipod adaptor I don't use). I'll disconnect them and see what happens, assuming the battery can hold a charge.

As to jump packs I’ve had good service from the book sized one I bought from Lidl- I got my brother one and he’s used it quite a bit as well. They have a light function and can charge things with a usb output.
Worth having one about the place as with my limited mileage currently and the cars parasitic loads battery voltage can’t be always relied on to start them.

I also had their top trunnions squashing out and replaced them with the Superpro ones that came with thick washers.

Bill
I had the same with my Mazda- left a light on and voltage very low and needed old style charger to get it going.
Then had alternator not outputting correctly and needed a new Alternator !
Don’t think your battery warranty will be honoured if the battery had been discharged below a certain figure.
Mine had a sticker saying 10.8v ISTR.