Light weight batteries

[clarkj93]

Car is a mk5 golf gti. No radio. No air con. No rear wiper. No Headlight washers.

It uses a 96 battery which is 650cca and 75Ah.

I'm wondering about using a 054 battery as it's half the weight and I can get one for 40 quid rather than spending 300 plus on a specialist light Weighed battery.

054 one I was looking at is 360cca ans 40Ah.

Anyone done anything like this? And what were your results? Car is really only used for track, road test drives and the odd pribably once a month trip to my mother's or to work when our other car is in use. My only concern is can it only start when irs just been fully charged? Is ignition/spark going to suffer at all?

Cheers!

[Krikkit]

Any budget for a lithium one?

It'll probably be fine, if you can might be worth coding out the alarm, or trying to disable things like ultrasonic sensors

[braddo]

And then buy a lithium battery starter from Halfords - they are the size of a small book and can start a flat battery easily. About £60 and you don't have to worry about jump starting or trickle chargers. They are also a battery pack to charge your phone etc.

[Tommie38]

Have you got an easy way of disconnecting the battery and is it OK to be parked without the alarm on?

If going for a small battery worth getting one of the battery clamps that allows for easy disconnection. At the very least get a ammeter on to see what your current drain is when parked up.

[Limpet]

Tommie38 said:

Have you got an easy way of disconnecting the battery and is it OK to be parked without the alarm on?

If going for a small battery worth getting one of the battery clamps that allows for easy disconnection. At the very least get a ammeter on to see what your current drain is when parked up.

That would be my suggestion also. Maybe even a solar (or mains) powered trickle charger

OP - When fully charged, the battery will be quite capable of starting the car (360CCA = 360A for 30 seconds - the starter probably pulls 250A). Once running, the alternator powers the car, with the battery only used as a reserve if needed (very rarely). The car will start and drive/operate normally. Given its low capacity, the battery will reach full charge pretty quickly too, assuming the original 140A alternator is still present and in good condition.

Once you've measured the current draw when the car is powered off, you can calculate roughly how long it will take to discharge the battery. Keeping it simple, a constant 40 mA drain will exhaust a fully charged 40Ah battery in about 1,000 hours, or a little short of 42 days. 40 Ah = 40,000 mAh, so 40,000 mAh / 40 mA = 1,000 hrs. And bear in mind that's completely drained from a full charge, so absolute best case scenario. In reality, the battery is likely to be incapable of starting the car a good while before that. I would have thought you'd be rolling the dice re starting after 3 weeks.

I would avoid any scenario that runs the battery flat and requires a jump pack or similar. Lead acid batteries do not like being fully discharged, and usually never fully recover.

[phazed]

Fitted a lightweight Varley Red Top gel battery to my TVR Chimaera some years ago.

Plenty of cranking power for the 5.5 V8……..

Brilliant thinking mounting it above the fuel tank

[donkmeister]

Honda S2000 has a tiny battery (40ish Ah IIRC) and a 2.0, so you will be fine with a similar battery.

However... Our S2000 sits idle for a couple of weeks at a time and has a "parking mode" camera, which despite being set to switch off at the highest selectable voltage still takes its toll on battery longevity if I'm not vigilant with the charger.

So I'd echo the above statements about minimising the parasitic draw on the battery. I'd even consider a cut-out if that works for you.

[phazed]

I fitted a cut out to mine. You can see in the photograph to the left of the battery. Worked a treat.

[944 Man]

063 might be a worthwhile saving. Batteries are all based on a number of fixed dimensions, and if you find a reference table you will soon be able to identify other that have similar key dimensions. For example: look at 096 and 100 and then a 063.

This is a bit of a rabbit hole...

https://www.puretyre.co.uk/car-battery-specificati...