OK, my apologies for the length of this, but now is the right time to bring it out - it's a document I wrote some years back after going through some research at work...
The Good, The Bad and The Ugly
Let’s start with the Bad…
Some years ago a purchased a brand new 1200 Sport (2 Valve). The year was 2007, the month was November. The battery as fitted was a Yuasa lead acid type. It had been a bit “sad” for the last 12 months and required an overnight charge on a day before I would be riding. The ability to hold its charge was decreasing, until it got to the stage where 2 days after being last used it had forgotten what it was supposed to do!
Now for the ugly bit…
Last Thursday, having received the regular “fill ‘er up mate” from the charger the night before, I rode to work. No issues there, just 42 km of fun. Went and did the daily grind. At the end, threw a leg over the bike and started for home base - still no issues there. I got home, killed the ignition while I opened the shed, got back on the bike and all she gave me was a clickety, click click when I gave her the thumb. Lucky I was strong enough to push it into the shed.
Battery “looked” OK on the multi meter, so I put it on the charge to see if recovery was possible. An hour later, all should have been in a better place, but no – still only clickety, click click. Battery finally died. OK to say I was miffed was a bit of an understatement - 6 years out of lead acid battery – I had been ripped off and something bad!
Good bit coming…
I had been doing some research for better batteries at work and had convinced myself that the “supposedly new” arrival of LiFePO4 (Lithium-Ferrous-Phosphate) batteries was the way forward. I had a shortlist of who was selling what battery, and where and for how much.
Having no choice, I lashed out and purchased a brand new Lithium battery, put it in “Black Betty” and the immediate response was a very quick start (no clickety, click click shenanigans) and a satisfying idle. In fact she sounded much better at idle than she had for a while, much smoother. Problem solved, I reckon.
The Technical Bit:
LiFePO4 battery technology has been around for 20 years. Used primarily by the US Military to power anything that needs batteries. However to us mere mortals, it is a new thing, with availability and quality only recently coming to the fore.
Lead acid batteries have been around for a long time. Generally these come in two formats: deep cycle and starter type batteries. As the name implies, these batteries are based on the interaction of lead plates being immersed in some acid. AGM and Gel batteries are based on the same technology, with the acid being in a gel (instead of a liquid – gel battery) or contained within the matting of the separator between the lead plates (AGM). When the battery is dead, there is an issue with disposing of the acid and the lead (lead is poisonous). Did I mention the weight of the battery?
The battery in my bike was a Yuasa YTX20-CHBS. This is the same as fitted to most (if not all) CARC bikes. This battery weighs 5.0 kg and while rated at 20 AH (Ampere Hours) which specifically means it can deliver 20 Amps for 1 hour, or 10 Amps for 2 hours, or 1 Amp for 20 hours – you get the picture? Also this battery can deliver 270 CCA (Cold Cranking Amps) for starting applications. This is the bit most of us are concerned with, as it is the CCA that gets you favourite Guzzi from an inert object into a vibrating awesome sounding beast, ready to take on a round Australia trip in typical Italian style.
There is a downside to the CCA rating though. All lead acid batteries (to my knowledge, which is highly limited) have a positive temperature coefficient. What this means, is that as the battery heats up (you need a tune up as your favourite ride didn’t start first go) the internal resistance of you battery increases. This means that the next time you press the starter button there is less CCA available to your starter because of this higher internal resistance. Chances are, if your battery is ageing, your next attempt at starting will probably only just work before the battery calls it a night. When this happens, a bump start, a replacement battery or a good recharge will be the cure. None of these are palatable, especially when this always happens at the bottom of the hill, and never at the top!
Lithium Batteries are different. If you don’t believe me, just pick one up. The first thing you will notice is how light they are. In my case, my new Lithium battery weighs in at 1.1 kg. That is only 22% of the original a saving of 2.9 kg (boy are we gonna go faster now that all this weight has been eliminated). I purchased an SSB LH14-BS from Batteries Direct in Peakhurst. The smart ones will notice that I replaced a 20 AH battery with a 14 AH – what gives?
The Lithium battery has a couple of features not present in lead acid batteries. Firstly the CCA for this battery is 425 Amps. That’s 57% higher than the original Yuasa battery. The other brilliant thing is that the Lithium batteries have negative temperature coefficients. This means that when you don’t get to start your beast the first time, the battery has heated up some (due to the initial attempt at starting) but the internal resistance decreases. What this gives you on the next start is more CCA. Yep, you got it folks, something for nothing. Therefore, if at first you don’t succeed (in starting), a better attempt is only seconds away. I don’t need a battery to supply modest amounts of current for a long time (if I did, I would get a deep cycle battery), I need a battery to put some life into a Guzzi so I can “go forth and enjoy”.
While the prices of LiFePO4 batteries are yet to reach commodity levels, there is a huge benefit in going to this technology. No lead, no acid, less weight, more CCA, smaller physically and safer all round for everyone. They can be recharged to 80% of their capacity in around 6 minutes with the correct charger. Pretty much any battery charger can be used WITH THE EXCEPTION OF BATTERY CHARGERS THAT HAVE DE-SUPLHURISING CIRCUITS. De-Sulphurising circuits (only in lead acid batteries from what I know) kill Lithium batteries. Hell, you don’t even need a battery charger, a 12 Volt power supply will work just as well, or even another battery hooked up to it.
Tony Mowbray – MGOA NSW
Just my opinion, that's all.