Lithium batteries

[Mankee]

I've been running the usual Ultramax/Yuasa/Rally Design type of battery in my track car for 2 or years now, and it has been perfect. I normally leave the battery on a conditioner, but when I can't be arsed, it barely loses any charge. The only time I flattened it was when the alternator packed up, but it was rescued without a fuss.

 

However, it does weigh over 5.5kgs and the lure of a lithium battery that weighs 1kg is very tempting. Just noticed a company doing the Skyrich batteries for a piffling £85 delivered for a 14Ah job:

 

http://www.amazon.co.uk/Skyrich-Motorcycle-battery-Lithium-YTX14-BS/dp/B00EXQVZII

 

Any thoughts on suitability? Will this work with the usual Ctek MXS 3.6 charger? Worth a punt for £85?

 

Edited by - Mankee on 18 Aug 2014 12:02:29

[Dr Slotter]

A CTek is fine, except never put it in 'Recondition' (or sulphurisation) mode as that'll destroy a Li battery. We use Shorai Li batteries in a single-seater and they work pretty well. We've only managed to destroy one by running the car with it leant on the exhaust manifold...

[elie boone]

you can keep the current battery as a cold start back up to aid starting if needed.

[Mankee]

I took delivery of one of these Skyrich batteries today. 902 grammes! Hopefully it has enough grunt to start my engine, otherwise it's just an expensive paper weight...

[Jonathan Kay]

There's another thread where a member is selling a Skyrich HJX14. That includes some discussion of cranking current and high-compression engines.

But that Skyrich has a CCA of 240 A. My PVR25 is probably a typical small lead-based battery for a 7 and has a CCA of 220 A.

Is there any accepted view or personal experience of a systematic difference in cranking current between lithium-based and lead-based car or bike batteries?

Thanks

Jonathan

[Mankee]

A few things I've noticed with my lithium battery compared to the previous Yuasa thing and from research over the interwebnet, which may or may not be BS.

1. First, it doesn't like being cranked and cranked, so cranking for oil pressure or using it to power the fuel pump to drain the tank is a no-no, as it'll go flat and useless pretty quickly.
2. Next, I'm sure I read somewhere that lithium batteries crank better with a bit of heat in them. So if the engine doesn't start first time, it'll often swing better second time round. Until it goes flat; cf. point 1.
3. I also read that the cold cranking amps rating cannot be directly compared between lithium and traditional batteries, but the lithium ones give better performance.
4. It barely lost any charge, in times of voltage, while sat dormant all winter...
5. ... and what charge it did lose, once the engine was running, it was restored by the alternator very quickly.
6. It didn't explode in a horrible garage fireball when it was overcharged at 15.5+v accidentally when I was wiring up the new (lightweight) alternator and trying to work out what was going on. Don't ask!

Conclusion: I'm well chuffed with it for £85. Does the battery in my track-only car get more hammer than the average road-based Caterham? Possibly.

[Jonathan Kay]

Thanks.

I'm intrigued by the reticence, including mine, in switching to these. Mostly neophobia?

Jonathan

[CharlesElliott]

Being slightly contrary, they are higher cost and are much easier to kill than a standard battery. Why would you buy one?

[Jonathan Kay]

Lower mass and lower self-discharge rate.

Jonathan

PS: I don't think that's contrary, yet. :-)

 

[CharlesElliott]

Lower mass of no benefit in a race car with minimum weight limit.

General performance not as good as normal battery (as per Mankee's email).

Kills battery if drops below certain voltage due to discharge (~8 normally).

It barely lost any charge, in times of voltage, while sat dormant all winter...

I'm not sure whether there are studies between normal and Li batteries, but I can leave my PVR25 all winter, not on a conditioner/charger, and the car will start on the button in the spring.