Corroded battery terminals. home made lithium battery pack.

[Turbojoe]

A few months back I changed my battery to A123 Lithium Ion that I built from cells harvested from DeWalt drill packs. (I also use these cells for my radio controlled airplanes and helicopters.) I hadn't really had any problems other than knowing the stock battery was quite old due for replacement. When I took it out I was surprised at how much corrosion there was on the positive terminal adapter. It was a problem just waiting to happen. I thought I'd post the pictures of them for those that are curious what they look like if they've never pulled their battery. I changed to Anderson Power Poles for a quick disconnect solution and don't have to worry about the stock terminals anymore.

Joe

[Triangles]

I've often pondered the use of lithium batteries. From what little I've learned about them they don't like being over charged (significantly shortened life span) even slightly and are potentially flammable when severely over charged. What do you u do to manage the battery charge? Where do you get the connectors from? I see the 6" ruler in the picture. That thing is tiny! What are the overall dimensions? You can't just throw something like that up here without details! Something like that could help me save room for some projects I've been tossing around like say room for a cruise control servo.

[Turbojoe]

Wow! Didn't expect this. I work nights so my schedule is pretty whacky but I'll try to put more together on this when I can.

As far as the volatility of lithium batteries go you're probably confusing these with Lithium Polymer and those certainly will burn down your bike and your house if you try to just plug one in to your bike without a properly designed charger/regulator in place. I also use Lithium Polymer cells in my airplanes and helicopters. They absolutely require the proper charger with algorithms for that specific chemistry. The Lithium Ion cell isn't quite so picky. As long as you don't throw any more than the voltage a motorcycle system produces it's pretty darned safe and self regulating. When I built my pack I added a balance tap so I could keep track of the cells health. To date I've checked about 5 times and all cells are completely equal in voltage. I don't worry in the least about flames erupting under me while on a ride.

I'll try to see if I have any more pictures of my pack build when I get home tonight. I think I still have a link to a great video I found with a great build of this type of pack.

Joe

[Turbojoe]

OK. Here's a little more on the subject:

You can buy pre-built 4S2P A123 motorcycle batteries for around $100.00. I decided to build my own because I already had all the cells I needed on hand. I had to buy the connectors and some 8 gauge wire but total build cost was less than $15.00 for me. So far I'm quite happy with the results on my bike. No more checking water level weekly because of the extreme heat here in Arizona. No more corrosion because of the acidic fumes released by the lead acid battery. About 1/5 the weight of the original battery. While my 4S2P battery pack is only 4.6 amps the potential cranking amps are far higher than the original battery. I wouldn't flinch at a momentary 100 amp pull from this pack. The bike will NEVER pull that much. Most racers that use the A123 batteries only use a 4S1P pack for 2.3 amps and to save as much weight as possible. The A123 battery isn't for everyone but it's perfect for me. If you have some DeWalt 36 volt drill packs laying around that you thought were bad chances are that only one cell is bad. Chances are very good that "bad" cell can be saved as well. All 3 of my 'bad" ones came back to life after being cycled a few times.

I'm posting another picture with the pack installed in the factory battery box. Also a link to an awesome build video on YouTube that inspired me to finally go ahead and git 'r done.....

http://www.youtube.com/watch?v=UTDctiyUa9E

Joe

[Triangles]

thanks for the info. Did some googling and it looks like you can buy one ready made for $125-$150 which seems to be comparable to DIY costs.

[burkbuilds]

Nice write up. I had no idea you could even do that and replace your existing battery with one built from old lithium cells. Your original submission regarding the terminals is dead on and those things give a lot of 500 riders a problem from getting loose or from corrosion. I switched over to a gel type battery a few months into owning my bike because I was constantly having to fill the reservoir and it was just one more annoyance that I didn't want to deal with.

[Turbojoe]

It cooled down to only 103 degrees today so I decided to venture out of the A/C and pulled the a123 battery from my bike to do a cycle test on it to see how its doing after being in the bike for the past 8 months or so. Because I fly R/C airplanes and helicopters I have some high end charging and cycling equipment for all of the different chemistry batteries I use. When I built the a123 pack for the bike I also added balance taps so I could check each cell during charge and discharge. This pack was built from a DeWalt pack that I bought on ebay and was who knows how old before I got it. It was sold as a "bad" pack. These cells were at least 5 years old before I assembled them into a pack. They just cycled at more than 90% capacity and I didn't even pull them down to voltage drop off. I don't think I'll ever put a lead acid battery in a bike again. If I can pick up a few more of the DeWalt packs for cheap I'll build a pack for my car. Lead acid batteries last in the extreme heat of Phoenix about 3 years at best even if you keep the water level up.

Joe

[Turbojoe]

Over 2 years on this A123 pack now and no sign of it weakening. I pulled it out this morning for a general inspection. Everything is still peachy. I put it on my good battery analyzer that I use for all my lithium based cells. After the normal start up cell checks the analyzer reported 100% charge and 100% cell balance for all 8 cells. Pretty dang good for a pack built from used cells! I've got lithium ion cells in my cordless vacuum, cordless lamps and even on LED under cabinet lighting. I love these things.

Joe

[Triangles]

I'm starting to question how wise it was to get one of these lithium batteries since I ride in winter. I got my pre-assembled pack late last winter. I guess I must be too impatient "waking up" the battery when it's cold. If it ever stops snowing I'll have to take a video of me trying to start it after it's been sitting out in the cold all day. My bike is usually harder to start than this example at a balmy 29F


It hasn't left me stranded yet. but I have flooded it and gotten a shotgun loud explosion out the exhust pipe a couple times. I'm also trying to start it between 8f and 20F, quite a bit cooler than the example video. For now I've learned to leave the choke off and try cranking it 3-4 times then turn the choke on and it usually fires within the next 2-3 tries.

You got any suggestions to get this working better in the cold Joe?

[Turbojoe]

Interesting to see your post now since I got my first taste of this last week. It was 36 degrees and she didn't want to start right away. From using these cells in R/C planes I already knew they didn't like cold weather. Before takeoff I always held the plane and ran to full throttle several times for a few seconds each to build a little heat in the pack. Then all was fine and I'd have full power under load. After 4 attempts on the bike it started up just fine. Pretty much like in the video. Getting down to the temps you're seeing may be a whole different story though. Even a lead acid battery would struggle with that. You may need to "crank" a little more heat into yours. A small heating pad would be a nice accessory for someone to design for bikes.

My pack was harvested from defective DeWalt drill packs and has been in the bike for over 2 years now. I really would have expected it to be getting pretty tired by now and may go ahead and build another backup pack just for the heck of it. The magic temp for me seems to be 36. Anything above that and it cranks like it's 90 degrees.

Joe

[Triangles]

I forgot to mention that I also tried leaving the headlight on for about a minute or so to "wake up" the pack but that didn't work. I'm guessing it doesn't put enuff load on the battery. My new cold weather starting strategy is:
1) crank about 3 seconds
2) wait 5 seconds
3) crank 3 more seconds
4) wait 20-30 seconds
5) apply full choke and try to start.

We'll see how this work for me if it ever stops snowing.

[Turbojoe]

Because temps will soon on occasion be dropping close to freezing I've been thinking about either getting a Battery Tender and leaving it on overnight or adding a connector "port" so I can plug in an additional single "warm" 4 cell Lithium Ion pack in parallel to offset voltage suppression only when it's crazy cold in the morning. No matter what I don't intend to ever go back to a flooded cell battery in my bike. The old, worn out Li-Ion cells I use have been working fine for me though admittedly they're probably not the best choice in extreme cold climates. Here in the Phoenix area if I had a garage to park her in rather than a carport I'd most likely have no problems whatsoever. Anyone north of Arizona will possibly have issues in really cold winter.

Joe

[Triangles]

Here in northern Ohio, I have a "warm" 45-50°F garage. The lithium batteries have no problem starting the bike. After cold soaking all day in the parking lot at work in the mid teens F. It takes a bit of effort but the Lithium pack has always started. Granted that has only been the end of last winter and so far this fall/winter. I think for cold weather (subfreezing) a 12 cell battery may help. I have no scientific basis for this, just my gut feeling. Since I have Anderson (forklift style) connectors on my battery and bike I have thought of making it easy to remove and take inside with with me. The battery is currently zip tied to the frame so while it's easy to disconnect, it's difficult to remove/reattach. FYI I have an 8 cell battery.

Turbo,
I like your idea of a port. Here's another thought, probably cost prohibitive, What about rigging up handlebar warming elements to warm the battery, either with the starting battery itself or your "warm" aux battery? You could turn on the heating, gear up and then 45 sec - min later maybe the battery would be warm enough? I suspect it would take more like 5 minutes but who knows without trying.

Until my Li battery leaves me stranded, I intend to experiment with better ways of "waking up" the battery.

[Turbojoe]

My battery is in the stock location so pulling it out at night and putting it back in in the morning isn't going to happen. Some kind of warming system would be great but it seems like anything for warming on a motorcycle (gloves, grips etc) is obscenely priced. It might be worth it to do a bunch of Googling for 12 volt non motorcycle (read cheap) warming products. Maybe there's something out there we could use.

I've been lucky and temps have been above that magical 36 degrees that cause me "problems". If I get crazy I may go ahead and add that "port" I talked about so I could easily plug in a warm 4 cell pack. I know that would get her started. Probably the easiest remedy for me. I use the Anderson Power poles too so it's an easy job for me. In the crazy cold temps the extra pack and a little heat on the main battery would still be a good idea.

Not to rub it in but the forecast for Phoenix metro is 70 degrees for Christmas day..............

Joe

[Triangles]

I have an 8 cell A123 4.6Ah battery. After a brief thaw to melt all the snow, it's cold again! Yay I let my bike sit out over night to video what happens to a Lithium battery when it is below freezing. The weather report says it got down to 9°F last night. I didn't get outside to give it a try until a little before 11am. It had warmed up to a balmy 20°F


My original cold starting strategy was:
1) crank about 3 seconds
2) wait 5 seconds
3) crank 3 more seconds
4) wait 20-30 seconds
5) apply full choke and try to start.

After my attempt to start it in the cold this morning I've amended my cold start (on a lithium battery) as follows:

1) crank about 3 seconds
2) wait 5 seconds
3) crank 3 more seconds
4) wait 20-30 seconds
5) crank again and if it turns over like it would start proceed to 6) otherwise go to step 4)
6) apply full choke and start.

It is important to leave the choke off until the engine turns over sufficiently. If you don't you can flood the engine, get a serious backfire out the carb, or shotgun like blast of an afterfire out the exhaust! And I do mean shotgun blast. I had to do a check of my legs to make sure there wasn't any shrapnel embedded in my legs Thankfully the bike and myself escaped unharmed.