LiFePO, Lithium Battery Concerns.

[DVB1]

I am interested in switching to a Lithium battery. I have two concerns:

1.) Does a Lithium Battery really need a special charger? Can I use my old school NAPA charger at 12V and 1 amp?

2.) If there is an issure, then do I need to change the charging system in the bike as well? I don't understand why the wall charger is no longer useful yet the alternator on the bike remains functional.

Thanks for any advice!

confused

 

[Maddevill]

My Shorai says to use their special charger but then says that a Battery Tender is ok. The thing I like about the Li batteries is that you hardly ever NEED to charge them. Sit for a month? Starts right up.

 

[auntiebling]

1) in an academic sense, yeah. my experience is that regular chargers work fine. if you managed to get a single cell at a lower voltage than the others, you'd need a "balance Charger" with a compatible harness to charge that individual cell. this is only relevant if your battery even has that level of detail. i don't think Shorai and the other hard case offerings do.

2) yep. i think there is a bit of CYA going on in this respect.

 

[epv]

Using LiFePO4 batteries in other applications, I have found them getting into a bad state of cell voltage imbalance pretty often - but I think using them as a starting battery on a motorcycle is a pretty optimal application for them from that point of view, as they're rarely going to take a from-empty charge and thus going to spend most of the time in a state where the onboard charging circuitry can apply some amount of balancing - assuming they contain per-cell shut resistors for that - if not, I think out of balance states would be a real risk. They need to have onboard charging circuits at any rate, since without them they'd be destroyed really fast, so I think the usual charging device are probably safe. I'd be interested in hear about longevity from any long time LiFePO4 users though!

 

[DVB1]

Does anyone have any experience with this product:

SSTZ14S-FP Scorpion Stinger 12v 387 CCA LiFePo4 Extreme High Output Battery

http://www.batterystuff.com/batteries/lithium-iron-batteries/sstz14s-fp.html

Description says, "Internally balanced so no special charging necessary."

Any thoughts?

 

[dmaxAl]

Word of warning here, this applies to all LiPo's, and I should have known better with my experience on quadcopters to know better.

Never.

Ever.

Let a Lipo battery over discharge.

Not even once.

Cos it's then buggered.

Backstory - switched to a shorai on the fjr because the fjfr is such a light bike it really benefits from the weight savings
I had the shorai balance charger but it was disconnected for a while and unknown to me the stupid aftermarket voltage/current monitor was drawing static current. Drew the almost brand new battery down to the 'fuxored' voltage level e voila one expensive, lightweight, paperweight.

Lipo's really should be getting balanced charged at least occasionally - once a single cell in the stack (stack of 4 for 12v systems) goes off it's throwing the whole charge off. V=IR and all that - balance charging charges the cells individually (that what the pigtail wire is for, access to the cells directly). Linky is for RC lipo's, but it's really no different to the automotive batts, interesting little read on what makes em tick and how to care for them..

http://www.rchelicopterfun.com/rc-lipo-batteries.html

 

[bobl]

I was told at the Shorai booth at the International Motorcycle Show in Long Beach, that my old Sears 2/10/50 amp charger would work fine. The only cautioned against chargers with float. ??

 

[ST Guy]

I am interested in switching to a Lithium battery. I have two concerns:

1.) Does a Lithium Battery really need a special charger? Can I use my old school NAPA charger at 12V and 1 amp?

2.) If there is an issure, then do I need to change the charging system in the bike as well? I don't understand why the wall charger is no longer useful yet the alternator on the bike remains functional.

Thanks for any advice!

confused

Technically, yes lithium battery charging requirements are different from lead acid requirements. But as you so astutely observed, motorcycle charging systems are designed for lead acid. I guess the answer is, since people get away with it, the charging system on your motorcycle is apparently good enough.

However, for long term storage, I'd use an AC powered charger that is designed for lithium batteries. Also, from a technical point of view, lithium batteries are best stored at less then a full charge. Topping them off and storing them fully charged will shorten their lifespan. So, unless you're going to store your bike for a really, really long time, don't bother with the AC charger. Caveat: If you don't disconnect your battery for those long storage times AND your bike has some draw on the battery with the ignition off (the majority nowadays do), then you'll want to check the battery from time to time and give it a bit of a charge.

From Battery University:

"Li-ion does not need to be fully charged, as is the case with lead acid, nor is it desirable to do so. In fact, it is better not to fully charge, because a high voltage stresses the battery. Choosing a lower voltage threshold, or eliminating the saturation charge altogether, prolongs battery life but this reduces the runtime. To satisfy maximum runtime, most chargers for consumer products go for maximum capacity; extended service life is perceived less important."

An excellent site: http://batteryuniversity.com/learn/article/charging_lithium_ion_batteries

 

[Dyn Blin]

ReHash

As long as there is no parasitic drain, the very (very) low self discharge rate makes a maintenance charge generally unnecessary. I've had Li ion batteries on the shelf for a year with no significant discharge.

Additionally Li ion (when in the optimal temp range) will throw most their amps into a level set of discharges until the cells are drained close to zero. This means even with short rides, you usually don't have to worry about charging levels. It's also a factor in why your 12 v charging system on the bike usually won't create an issue- you're normally not quite to "full" charge capacity when you shut the engine down.

However, at the point of full discharge, the cells are fuckeled. 'also don't want to take a chance at overcharge with a charger that maintains a float setting- runaway exothermic reactions may result in fire

 

[phocup]

Didn't want to make a new thread for this, but I've seen a setup that allows you to quickly charge plug the charger to your Shorai battery without the need to take the seat off.

There's two cables. One is mounted on your bike and provide an external adapter port to the battery, and the other one goes from the charger to the adapter port. Looks like this. I can't find anywhere to buy another set of cable to set mine up this way as well.

Anyone know where I can buy a set ?

 

[auntiebling]

That looks like a clever adaptation of a computer serial port from the dark ages before USB. I'd wander over to halted supply in sunnyvale and rummage around for a male and female set the cut up a factory balance charger cable as needed

 

[explorin]

Life bateries are not lipo Bateries. Lipo charge up to 4.2v per cell. Life is 3.65v per cell. Optimum voltage for life is 3.2v a cell.

You understand your charging system on your bike is to agressive for lipo or life right?

Life are lithium phosphate. Much safe than lipo, can be over charged and over used without to much damage. They do last longer as well.

Also, every life or lipo will need to be balanced. Lipo literally every time it is used. Life tends to stay more balanced. Balanced meaning the cells stay the same voltage.