Light on it’s own isn’t the whole story. There is a lot more to it related to where the mass is in relationship to the bike CoG and required geometry but my rule of thumb for weight reduction is to hit it in this order - 0. Any relatively low cost stuff where unnecessary weight is being carried - rider, heavy bodywork etc. this for me includes swapping out a lead acid battery for lithium. 1. Unsprung mass (all the stuff under the suspension springs - wheels, tyres, discs, brakes, fork bottoms, swingarm etc.) 2. Engine speed rotating mass (crank, flywheel, sprag, gen rotors) 3. Rider and kit 4. Chassis 5 Less than engine speed rotating mass (clutch, gearbox)
liPo’s are considerably more dangerous than normal Li Ion batteries used in Laptops, phones, cars etc. However they all need charging with the correct charger that communicates with the BMS module in the battery pack to ensure it’s safe. And the bigger the battery pack the more explosively it can go wrong if abused as per the Electric Motorcycle battery fire doing the rounds! I might charge one in a detached garage but never in a garage in my house! A smaller Lithium battery just replacing a lead acid on a bike is safer but again only with the correct charger. If I got one for my bike it would be LiFPO3 battery which will denature itself if shorted or overheated and consequently becomes an inert brick and can never burn! You can drive a bail through those and it’s will spark and then die quietly.
They're standard fitment on a number of new bikes. My wife's Aprilia RS 660 comes with one. Weighs sod all. I have had it on a NOCO Genius 1 (multi-battery type) tender for a year without problems. Thinking of adding one to my V2 trackbike for the hell of it.
Standard replacement Lithium Ion batteries are normally fine with a correctly rated charger, my son’s had them on a number of V4’s. I’m a chunky chap sonI could save a lot more weight on my V2 with a personal diet rather than a battery diet!
Which I’m sure would be fine but check the parts diagram for the v2 Bayliss first and note the different battery lead (earth iirc). The Bayliss has an Li battery as standard with an upgraded lead. @bettes will confirm.
So what's the story if you add one of these new fangled charger sensitive batteries to your old bike with the original charging system designed for a Lead/Acid battery? I'm presuming it's not recommended.
Scaremongering headlines don’t help people adapt to new technologies. All batteries carry hazards - good old fashioned lead acid included. Anything with the capacity to store energy carries an element of risk that the energy could be released in an uncontrolled manner. MSM seem to love to focus on anomalous events involving the mismanagement of lithium batteries. Where are the stories about explosions caused by charging lead acid batteries unventilated spaces? Or the numerous acid burns / eye injuries that have accompanied acid usage over the years? I recall that every warehouse using battery powered handling equipment also has an eye wash station and lot’s of helpful warning signs on the wall next to the battery charger….. Lithium batteries come with their risks but they also come with big benefits. Aside from the weight, they simply last longer without needing the kind of regular charging that a lead acid does and can give out constant power for longer without the gradual drop off you get from other technologies. I have just pulled the lithium battery from my bike - It’s sat in the garage for almost 2 years with no usage - despite me knowing the best thing I could have done is to take it off and bring it inside. The battery still shows as being fully charged on the built in led indicator. I’ll run it though some discharge and charge cycles on a decent charger to give it some love and it will be just fine. A lead acid battery subjected to the same neglect would be scrap. We have discussed this so many times - but for modern bikes with modern charging systems swapping to a lithium battery is a none issue. Older bikes - research is advised.
Lithium chemistry batteries are (or used to be) vulnerable to charging voltages above 14.9 volts. I’m pretty sure the latest generation MOSFET regulators do this for lead acid as well anyway. Andy
You would want to check that the alternator is regulated correctly and isn’t putting too high a voltage or charge rate into the battery! It would be a case of matching the specs of the two batteries pretty carefully and ensure if the Li-ion (or LifePO3) can handle the charge rate the alternator is regulated / rated for. Not a great area for guesswork. LifePO3 have the advantage that if you abuse them (too high a charge rate or a short, not much chance of the first as they take a phenomenal charge rate too) they just turn into a useless brick rather than a firebomb!
If you’re changing to a lithium battery… Upgrade the leads and if on older models, replace the R&R with a mosfet jobby and you won’t go far wrong. With the Panis, they recommend a bit of heat reflective material around the battery and a vented battery cover.
It should be common sense to use a suitable charger for the type of battery that is being charged. Interesting read - comparing newer Lithium Iron Phosphate (LiFePO4) against other Lithium batteries…. including why they are inherently safer. “Lithium phosphate cells are incombustible, which is an important feature in the event of mishandling during charging or discharging. They can also withstand harsh conditions, be it freezing cold, scorching heat or rough terrain. When subjected to hazardous events, such as collision or short-circuiting, they won’t explode or catch fire, significantly reducing any chance of harm. If you’re selecting a lithium battery and anticipate use in hazardous or unstable environments, LiFePO4 is likely your best choice. It’s also worth mentioning, LiFePO4 batteries are non-toxic, non-contaminating and contain no rare earth metals, making them an environmentally conscious choice.” https://ecotreelithium.co.uk/news/what-are-lifepo4-batteries/# https://relionbattery.com/knowledge/how-are-lifepo4-batteries-safer-than-other-lithium-batteries
