Competition Batteries - Ah size....discussion..

[Exminiman]

Considering replacing the battery, currently have an Astra Diesel battery, which is great, lots of cranking, peace of mind but very heavy....

So started looking am alternative, usual suspects Varley Redtop 15, Odyssey PC535......but they all have a much lower Ah @ around 15 Ah than even the standard battery at around 45Ah.

Now you can reasonably argue that the Ah is not so important on a competition car as its not running the all the stuff on a normal car and cold cranking (CCA) is more important, because of high compression etc.

Thing is I am concerned that my Weber will over fuel and flood, its does some times, and needs more cranking and I will need the extra battery reserve capacity of the standard 45Ah or so...to get it going ...

Weight is important, but is peace of mind more important ?

[850RS]

I run an Odyssey pc680 with a total loss (no charging system) and I can do a full weekend at the track without needing to charge the battery. Keep in mind I only run LED brake lights and don’t have headlights or turn signals to worry about. It is super lightweight and packages well since you can mount on its side. I also have a Weber and do often spend a good amount of time trying to get it to start. The motor is an 11:1 compression ratio 998.

[Exminiman]

I run an Odyssey pc680 with a total loss (no charging system) and I can do a full weekend at the track without needing to charge the battery. Keep in mind I only run LED brake lights and don’t have headlights or turn signals to worry about. It is super lightweight and packages well since you can mount on its side. I also have a Weber and do often spend a good amount of time trying to get it to start. The motor is an 11:1 compression ratio 998.

Thanks for the info, nice neat installation BTW.

If it was SUs wouldn't be crossing my mind, its just very occasionally, the Weber just doesn't play nicely....

So the PC680 is only 16Ah and 170 amps CCA, which is around where I was looking

[360gts]

I run an Odyssey pc680 with a total loss (no charging system) and I can do a full weekend at the track without needing to charge the battery. Keep in mind I only run LED brake lights and don’t have headlights or turn signals to worry about. It is super lightweight and packages well since you can mount on its side. I also have a Weber and do often spend a good amount of time trying to get it to start. The motor is an 11:1 compression ratio 998.

I use the Odessy PC925


compact and lots of cranking. however, I wouldn't say it is lightweight...weighs in at 11 kilos.
Can get a weekend out of it...I have a second one with the quick connects just in case I ever need to boost in the pits.

[Spider]

I haven't looked so I don't know what's available these days, but is there a Lithium LiFePO4 type battery available ?

I bought for for another application, it was a light as a feather.

It would likely need a different Alternator or an interface between the Charging System and the Battery, as they have 'fussy' charging needs, but even taking that in to account, it would be around 1/4 of the weight of anything Lead based.

I'd strongly suggest though, if you were to go this route, removing the battery from the vehicle at all times it's not being driven !

[Linesy]

I run a Century PS12180. Its an VRLA so can lay flat and is AGM.

I use an assistant jump battery for for start of a race day, just to help as running 12+ comp and circulating cold oil etc.

It is only 5.7kg, so nice and light.

Have run these in several race cars of differing variety with no failures.

[atm92484]

Another vote for the PC680. I'm running one in my Sprite (1275, 13:1, SUs) and Seven (1.5L Pre-Crossflow, 14:1, 2x Weber DCOE). They do fine starting both cars except for cold mornings in the early spring or late fall - I'll use a jump pack for the first start of the day. Once the engine is warmed up its fine for the rest of the day. I do top the battery off between each session just so it is ready for the next but could go the day without charging.

[360gts]

I know the 925 is a heavyweight 26 lbs. but it does have 48 mins. reserve and great cranking power. I am giving up some weight advantage ...BUT....the last thing I need is to have the engine stall or cut out in the pre grid and then....have insufficient power to restart a hot engine...quite embarrassing...and a pain for the drivers behind me. The PC680 is about half the weight....a good battery but not as good as the 925... Since I am just competing in vintage...a few extra pounds is a trade off for peace of mind when you are sitting there in a hot mini

[Exminiman]

I know the 925 is a heavyweight 26 lbs. but it does have 48 mins. reserve and great cranking power. I am giving up some weight advantage ...BUT....the last thing I need is to have the engine stall or cut out in the pre grid and then....have insufficient power to restart a hot engine...quite embarrassing...and a pain for the drivers behind me. The PC680 is about half the weight....a good battery but not as good as the 925... Since I am just competing in vintage...a few extra pounds is a trade off for peace of mind when you are sitting there in a hot mini

This was my worry, hot engine, Weber and me going redder by the second

[imack]

I've been using a Powerlite PS-20 lifep04 for 5-6 years.
Very light, about 2kg if I remember correctly.
Has started new engine builds with 11.5:1 cr and SW23 cam without issue, including cranking to build initial oil pressure.
Strangely, they don't seem to be available anymore, so maybe there's been issues with them.

[Exminiman]

EDIT, for some reason the link has now gone dead……maybe product shouldn’t have been listed?

Have changed link below to what t(ey sell now

https://www.powerlite-units.com/lithium ... ce%5D=DESC

This one ? https://power lite DEAD LINK

They are not cheap are they

Do include a charger though, which I suppose you need being Lithium Iron ?

Presumably you cant charge direct from car ?

[imack]

It wasn't that expensive, I think it was about £180. It came from minispares.
It came with a charger, direct replacement for standard battery. Battery management system electronics built into the battery.