Help diagnosing, and watch out for A123 mini batteries...

[scaylabs]

First, here is why I say to stay away from the A123 batteries until I hear back from the manufacturer or I can figure out what happened:
http://www.youtube.com/watch?v=HRFWWeNNPzo


Now, here is the sequence of events:

Yesterday, first ride. The bike was finally ride-able yesterday and I went for a short slow ride to the gas station. On the way the signals fuse blew, which I think was because my horn wire was hanging loose and might have touched the frame. Pulling into the garage, maneuvering over a small step, the main fuse blew.

Today. Taped up the loose horn wire, replaced the signals and main fuse. Bike won't start. Traced it down to a failed Coil relay and replaced with the horn relay. The bike starts instantly and I ride to have lunch 2.5mi away and back with no issues.
I'm going for another ride later in the afternoon and the bike starts normally. While warming up, after a couple minutes, it slows down and dies. I hit the starter button and only get one slow turn of the engine. I hit it again and I see smoke coming from under the seat, and that's the video you just saw above. No fuses blew.

I usually try to do only one mod at a time to know what failed but it wasn't an option this time around.

Things done:
Coil relay mod.
Horn relay mod.
Replacement RR
HID kit.
New flasher, removed Turn Signal Control Unit and associated wiring.
Relocated everything to under the seat tray.

Before the battery, "failed", the cranking power seemed more than sufficient.
I emailed the manufacturer of the battery, including the video, to see what they think might have caused the failure, but again, it didn't seem to be struggling at all until that last deadly crank.

Here is the build thread: http://www.thegsresources.com/_forum...d.php?t=172955

Sorry for the long post, trying to put all the info I can think of.
Any ideas??

[Steve]

I know that is seems that many are getting away with it, but I think you are asking a tiny little battery to go WAY beyond its capacity.

If you were using them on a kick-start machine and bascially used them for a voltage reference point for the R/R, it might be fine, but there is no way that they can provide 50+ amps for starting the bike and be expected to survive.

Personally, I think you got off easy.

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[tthayer]

Were you trying to use a lithium-ion battery pack to start your bike? There is a reason vehicle batteries list crank amps. I'm amazed those battery cells held up for as long as they did without exploding earlier. You could have really hurt yourself. I've seen Li-on cells shoot blue flames 2-3 inches that were hot enough to cut metal. No joke.

http://www.shoraipower.com/s-75629-GS1100-ES.aspx
That battery is rated at 210CCA.

[scaylabs]

Were you trying to use a lithium-ion battery pack to start your bike? There is a reason vehicle batteries list crank amps. I'm amazed those battery cells held up for as long as they did without exploding earlier. You could have really hurt yourself. I've seen Li-on cells shoot blue flames 2-3 inches that were hot enough to cut metal. No joke.

http://www.shoraipower.com/s-75629-GS1100-ES.aspx
That battery is rated at 210CCA.

This one was listed as 135 CCA, 4.6AH, but I guess that is not enough huh?
I've seen other people get away with it but you may be right that it was pushing it.

[pete]

I'm really keen to see what the manufacturer says.

Everyone's been saying how these batteries are awesome and I've been thinking about them for the 450 as they should fit in my tail piece.

However, if they're dangerous I don't want them.

I have seen guys being told not to use them for testing of bikes (ie. lots of cranking) and only to use them when everything's sorted and you basically just need to start and go, but I thought that had more to do with capacity (AH) than safety, but maybe it is to prevent them overheating and exploding?

That Shorai may fit in the tail piece but I'd have to measure to be sure...

[tthayer]

Our 450's may work better as they don't require the same CCA rating to turn over. I'm seeing batteries for our bikes rated at 160-165 CCA's. 135 is only about 15% underpowered as opposed to over 35% lower than required for the 1100.

Li-on packs will try to output at full voltage for as long as they can hold out, even at the risk of harming the pack (depending on the battery controller), whereas lead-acid batteries have a decreasing output as they become exhausted and so you just lose cranking power instead of causing increased load on the battery circuit.
My preference would be to stick with lead-acid unless you have a proper battery controller installed in order to prevent overloading or overcharging the battery. Some people with laptops may have noticed that their computers will actively prevent charging or use if the battery is too hot or if the circuit has charged to 99%. Without a controller you are basically going to constantly overcharge/overload that battery repeatedly and the results will be predictable.
Here is a link that describes a charging and discharge circuit:
http://www.youtube.com/watch?v=qVq94aN5mNM

That being said, if you are using a battery controller then you probably won't have any safety issues to contend with.

[pete]

Our 450's may work better as they don't require the same CCA rating to turn over. I'm seeing batteries for our bikes rated at 160-165 CCA's. 135 is only about 15% underpowered as opposed to over 35% lower than required for the 1100.

Li-on packs will try to output at full voltage for as long as they can hold out, even at the risk of harming the pack (depending on the battery controller), whereas lead-acid batteries have a decreasing output as they become exhausted and so you just lose cranking power instead of causing increased load on the battery circuit.
My preference would be to stick with lead-acid unless you have a proper battery controller installed in order to prevent overloading or overcharging the battery. Some people with laptops may have noticed that their computers will actively prevent charging or use if the battery is too hot or if the circuit has charged to 99%. Without a controller you are basically going to constantly overcharge/overload that battery repeatedly and the results will be predictable.
Here is a link that describes a charging and discharge circuit:
http://www.youtube.com/watch?v=qVq94aN5mNM

That being said, if you are using a battery controller then you probably won't have any safety issues to contend with.

Yep, makes sense. I believe 165CCA is the factory standard Yuasa rated one, so not too far over as you say.

Everything that you said there makes perfect sense, and all those sorts of devices including things like cordless drill chargers definitely have battery management going on.

I have seen several instances of reports of how good these batteries are where the example used is cordless drills and other cordless tools like that, which also gels with the fact that there is battery management going on.

It now makes so much sense!!!

So, after viewing that video, all we need to do to make the A123 batteries safe on the bikes is design a monitor/management circuit that will cut the connection to the electrical system if any individual cell goes below 2.1V and also will bypass charging an individual cell if it reaches 3.7V.

That's tempting... very tempting... I wonder how hard that would be? More Googling required me thinks...

[Buffalo Bill]

Downer…

Kind of like watching cash burn. Not a pretty sight…

I keep away from those relay mods myself. Just clean connections and wires, solder all new connections, no crimp connectors.

I'll never try those batteries after this thread, Thanks!
Just go with a small lead cell.

Bill

[scaylabs]

...I think you are asking a tiny little battery to go WAY beyond its capacity.

...there is no way that they can provide 50+ amps for starting the bike and be expected to survive.

That 50 amps starting number was what I found when researching this before I went for the battery.

My reasoning was: given that CCA are the amps the battery is capable of giving after 30 seconds of cranking (135A in this case), how can it not be sufficient if I'm only cranking for 1 second?

There must be something else to this equation.



I don't mind the loss of the battery ($$) or having to redesign to accommodate a larger battery, as long as I (we) can learn something.

[pete]

I think TThayer's post above clarifies it enough for me, in that these batteries simply need to be managed correctly, especially after watching that video he posted.

There was another thread on here where a guy (can't remember who) said he had experienced a number of thermal events with A123's but he couldn't elaborate for legal reasons.

I'm wondering if it really is a simple matter of needing proper battery management to avoid these issues.

[Steve]

I'm wondering if it really is a simple matter of needing proper battery management to avoid these issues.

Just to provide a bit of insight, here is a clip from Wikipedia about Li-Po batteries:

LiPoly batteries must be charged carefully. The basic process is to charge at constant current until each cell reaches 4.2 V; the charger must then gradually reduce the charge current while holding the cell voltage at 4.2 V until the charge current has dropped to a small percentage of the initial charge rate, at which point the battery is considered 100% charged. Some manufacturers specify 2%, others 3%, but other values are also possible. The difference in achieved capacity is minute.
Balance charging simply means that the charger monitors the voltage of each cell in a pack and varies the charge on a per-cell basis so that all cells are brought to the same voltage.
It is important to note that trickle charging is not acceptable for lithium batteries; Li-ion chemistry cannot accept an overcharge without causing damage to the cell, possibly plating out lithium metal and becoming hazardous.[5] Most manufacturers claim a maximum and minimum voltage of 4.23 and 3.0 volts per cell. Taking any cell outside these limits can reduce the cell's capacity and ability to deliver full rated current.
Most dedicated lithium polymer chargers use a charge timer for safety; this cuts the charge after a predefined time (typically 90 minutes).

Something tells me that the charging systems on our bikes don't quite fit those parameters.

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[pete]

Just to provide a bit of insight, here is a clip from Wikipedia about Li-Po batteries:


Something tells me that the charging systems on our bikes don't quite fit those parameters.

.

100% Steve! Pretty much gels with what the guy in the video TThayer was saying and how he has those management circuits made up, although for the A123 cells he said 3.7V maximum and I think it was 2.1V minimum, although it could've been 3.1 now that I think about it...

[scaylabs]

Something tells me that the charging systems on our bikes don't quite fit those parameters.

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That makes sense also.

But then why aren't the guys using them in smaller displacement bikes blowing them up also? The charging systems are all pretty much the same.

Oh, and according to my manual the starter uses about 80 Amps , too close to the 135 CCA of the battery for comfort, but not over either.

Thanks for helping me think through this guys, I appreciate it.

[tthayer]

I don't think Li-on is inherently unsafe as long as it is applied properly. The new electric cars and motorcycles use Li-on with few issues, though the waters are still pretty much untested as far as how long those huge battery packs will survive in normal day-to-day driving. I have seen a couple of Chevy Volts and Nissan Leafs tooling around Portland lately and it is a pretty cool feeling to see the future happening right now (well, maybe not for the Volt).

[Steve]

I don't think Li-on is inherently unsafe as long as it is applied properly. The new electric cars and motorcycles use Li-on with few issues, though the waters are still pretty much untested as far as how long those huge battery packs will survive in normal day-to-day driving.

How much would you like to wager that those cars were designed with those batteries in mind, and therefore have the proper charging system?

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