Better Battery?

[Triangles]

Now that my '94's battery has reached the end if it's life, I want something more maintenance free. So far I've found: AGM(absorbed glass mat) sealed battery, and two types of lithium batteries that are possible candidates. The two lithium choices are both LiFePO4 (Lithium Iron Phosphate) based. One is assembled from round cells. and the other from rectangular cells (prismatic). Costs are ball park as follows:

AGM -- $85
Lithium -- $100
Lithium (prismatic) -- $130

I'll post more info as I gather it. If anyone has experience with these please share.

Edit: 1-25-13:

The information below is by no means an endorsement, it's just what I've found scouring the net.
Yuasa OEM specifications:
LxWxH 5.3125" x 3.1875" x 6.3125"
12AH
Part numbers.
EN500A: YB12A-A
EN500C: YB12AL-A2
The dimensions are the same for both the difference is the terminals are inverted between the two.

AGM batteries:
The only AGM battery I could find that was specified as compatible with the Vulcan 500's is the Motobatt MB12U. It has four battery terminals so it will fit both first gen and second gen EN500's.
AGM Motobatt MB12U $82
[urlhttp://www.motobattasia.com/batteries.php?modelandyear=310&manufacturer=3&engine=309]Manufacturers web site.[/url]

I also found a couple of other batteries based on dimensions that might fit with some modification. I wouldn't recommend these as they are thicker and taller than the OEM batteries.
Westco;
LxWxH 5.31" x 3.50" x 6.56"
EN500A:12V14-A2
EN500C:12V14L-B
Again different part numbers for terminal polarity.
Manufacturer's website

Additionally on this site they have the "Adventure Power" brand which I could find no manufacturers information. If interested they have batteries with similar dimensions to the Westco batteries that might work.

Lithium:
As I mentioned above there are two specific types I'm looking at. A123 Round cells assembled into a pack. These will require some customizing as they generally come with an Anderson style connector and are physically much smaller. This is the particular battery I'm considering. It's 13.2V4.6AH

For a drop in Lithium battery a company called Shorai makes a drop in battery. These are assembled using rectangular "prismatic" cells. They list their battery as being lead acid 14AH equivalent but do not provide the true amp hour rating of the battery. I'm assuming it is probably similar to the A123 cell pack above.
http://www.shoraipower.com/
EN500A: LFX14A5-BS12
EN500C: LFX14L5-BS12
Again different part #'s for different terminal polarity.

You might think these lithium batteries are woefully under rated being 4.6AH compared to the OEM lead 12AH battery but for the purposes of starting the motorcycle this is not the case. Comparing the two battery technologies are as the cliche, apples to oranges. The first thing to understand is it's power aka watts that crank the engine. Watts is defined as Volts x Amps. Lithium batteries are at a slightly higher voltage and under load (ie cranking the engine) their voltage drops less than a lead-acid battery. Due to these two factors when you are cranking off a lithium battery the battery's output voltage is in the neighborhood of 3 volts higher than a lead-acid battery would be. Since you have higher cranking voltage you need less amps.

Pros and Cons:
Both lithium and AGM are far better choices than the OEM flooded lead-acid battery so I'll focus on the differences between lithium and AGM. Keep in mind when I say "lithium" I am referring to the LiFePO4 (lithium iron phosphate) chemistry. There are many other flavors of lithium batteries that I am unfamiliar with and the following may or may not apply. I am only writing about what I have learned about the LiFePO4 chemisty.

AGM: These batteries are generally cheaper and there isn't a whole lot to worry about with them. Like their cousins, the flooded lead-acid batteries they still need to be put on a battery tender when neglected for long periods of time. However their self discharge rate is significantly lower.

Lithium: Other than form factor, there aren't any major differences between the two styles of lithium batteries mentioned above. The lithium batteries are very robust except when excessively overcharged or completely drained. Supposedly the these newer technology lithium batteries are very tolerant to being over charged compared to their predecessors lithium battery technology. You really don't have to worry about the bike's charging system over charging the battery but you can very easily toast them by leaving them on a standard battery charger. I don't really know much about using chargers designed for lead-acid except that you MUST disable the "desulphation" mode or you will likely toast your expensive lithium battery. The other weakness is on the discharged end. If you allow the battery to discharge to below 2.5v per cell (10v) you risk toasting the battery. If you're curious I can explain how this happens. Additionally in cold weather (ie below freezing), the lithium battery may need to be "woken up" This can be done by turning on the head light for a few moments before trying to crank the engine or simply by trying to crank the engine. The battery's output will increase by the 2nd or 3rd attempt to start. A major advantage is that you can let a lithium battery sit for over a year without the need for a float charger. In fact using a float charger on a lithium battery may actually shorten the battery's life. The exception to this being if you uses a battery management system specifically designed for lithium batteries. Such systems are complex and expensive and for the most part entirely not necessary. Adding a circuit that will cut the battery off when it reaches 10v would be advantageous. However I like to follow the KISS (Keep It Simple Stupid) principle and won't bother with such a safety circuit. For those worried about fire risks, the LiFePO4 batteries would have to be over charged with 60-80volts before they would combust, in other words, not going to happen. I have seen a prismatic cell that was forgotten about on a high current charger for 10 hours past it's charge time. The result was a melted battery, melted carpet, stinky smoke, but no fire.

[burkbuilds]

I've had really good luck with the AGM batteries over the years. No adding fluids every couple of months and they seem to hold a charge well and be very reliable. I've not tried the other batteries you mentioned, but I'd find it difficult to see how they could perform significantly better than an AGM for the purpose of a bike battery.

[Triangles]

I've updated with the information I've found. I'm ordering the A123 cell lithium battery. I'll post the results when I get it.

[burkbuilds]

Good luck with the Lithium. I'll be interested in your long term experience with them. Right now I think Boeing is wishing they had not gone that route, but the final judgement is still out on that.

[Triangles]

I figure the custom pack will give me room for my fuel injection controller and components. Assuming work doesn't get in the way, I'm planning on having my fuel injection running by some time this fall. It's been almost 2 years since I've made any progress but the itch to work on it again is getting stronger. Once I'm done with that, I also have an '89 Honda that will be much easier to fuel inject.

[Turbojoe]

I just happened to pull my home made A123 pack out of the bike Saturday to see how it's doing after 15 months. I have a high end charger/cell balancer I use for my radio control hobby because I use everything from ni-cd, nimh, lithium ion (a123) and lithium polymer cells. The pack was fully charged and cells balanced immediately. No ill affects from being in the bike in temp ranges from 26-117 degrees. Also no add on regulator was necessary. It gets charged directly from the bike charging system. The cells I used were harvested from DeWalt warranty return "defective" packs that I bought cheaply from various places. ebay is a good place to find them too. There is a YouTube video link in my post in November of 2011 that shows exactly how to build a pack for the bike HERE http://vulcan500.com/forum/viewtopic.php?f=25&t=421.

Joe

[Triangles]

Glad to hear it's still working. I had forgotten about your DIY pack. I actually was going to go that route but I couldn't find the batteries and supplies cheaper than I could buy the pack. I'm still waiting on the slow boat from China.

[Turbojoe]

Yeah, I bought most of my cells a few years back when you could get the DeWalt "defective" packs cheap. I haven't checked lately but I'm sure they're not as cheap now that people have caught on and started buying them up for re-sale. I've got almost 40 cells so even after building the 4S2P pack that's in the bike and a 4S1P emergency pack I still have plenty left over for R/C planes and helicopters. A123 are nice rugged cells that work well in many applications.

Joe

[Triangles]

Joe,
I got my lithium pack installed. So far I am less than impressed. Maybe I don't have all the knowledge I need about these A123 lithium cells. My understanding is the pack I have is a 2.3Ahr and the nominal voltage is 3.3v and they can be safely charged at up to 10A. So a 4 in series 2 parallel pack (commonly abbreviated "4s2p")would give me 4.6Ahr @ 13.2 volts. When I received the pack it was at 13.45v I assumed this was a fully charged battery. I have an old school charger lead acid charger (probably from the 70's) that puts out 14V @2A. I charged the battery with this until it got up to 13.8V which took about 15 minutes. The battery had just come out of my warm house and into my "warm" garage about 55F. Then I tried to start the engine. It cranked over and started but not with as much "oomph" as with a fully charged lead acid battery. After sitting all day at work in the mid 20'sF, when I tried to start the engine it turned very slowly and took till the 3rd or 4th try before it fired. I've ridden a half dozen times so far and when it sits in the cold it always takes several attempts before it starts. I've read that lithiums really don't like the cold but I didn't think it would be this severe.

So What I'm really trying to find out is what is the fully charged voltage of these cells? I've seen anywhere from 3.3 to 3.7v/cell specified at various places I'm assuming these are for various types of lithium cells. the pack is made from 26650 A123System Cells. While typing this I just realized that these are lithium nanophosphate chemistry. Is different from the LiFePO4 chemistry?

[Triangles]

I think I found my answer. 3.3v is the "nominal" or designed output voltage. A fully charged cell is between 3.5 and 3.55 v/ cell from looking at the A123 systems documentation. so in theory a fully charged pack is 14.2v and a 95% charged pack would be 13.3-13.5v.

[Turbojoe]

Something isn't right. I'd do a cranking voltage check. I'll bet you're going to find either a bad solder joint, bad connector, a dead cell or just need to do a few charge/discharge cycles to wake it up. While the A123 cells do sag a bit in cold weather you shouldn't notice it on your bike. I was called in to work at 3:00 am @ 26 degrees a month or so ago. Never seen it that cold here before and I half expected slow cranking. Never happened. She cranked and fired as normal as can be. The cells I built my pack from are many years old and came from "defective" DeWalt packs. That's why I think you'll find a problem somewhere with yours. I'd really recommend discharging the pack down to about 2.5 volts per cell then recharging 2-3 times. That can bring a sluggish cell back to life. Because of my radio control hobby I have a lot of cool stuff available that I can put to use. My bike pack has balance taps added so I can check the voltage of each individual cell. I also have a high end charger that uses these taps to charge each cell and balance the entire pack. Great for my hobby but at $200.00 it's too expensive for a once in a while use. A123's don't seem to care much what they're charged with though and I've seen people charge them directly from their car battery with a long (high resistance) charge lead.

The LiFePo batteries are a whole 'nother aminal. I haven't messed with them yet as they require buying yet another chemistry specific charger. You can't safely charge them on a basic charger. The A123's are super rugged and seem to absolutely thrive on abuse. While they are heavy for R/C use compared to Lithium Polymer cells I use them mostly in my larger aircraft and of course the motorcycle.

I think you'll find an issue somewhere in your pack or connector. Definitely try a few cycles of the pack if you don't find anything wrong. With use I'll bet it will come to life and you'll love it.

Joe

[Triangles]

Thanks,
I will dig into it. I'll leave the key on with headlight until the battery voltage drops then use my 2A charger for 3 hours to charge it back up. I really don't want to ruin the nice shrink wrap just to check each cell voltage, but maybe I will. I am wondering if maybe my starter is dying. My friends truck had the windings start to short where the motor would crank over but wouldn't start because the starter was drawing insane amounts of current drawing battery voltage down even with new batteries. I'll have to dig thru the service manual, maybe there is a procedure to check the starter there.