Lithium Battery Systems

I've been pondering the next major phase of my Lectra motorcycle. I'm sure the battery pack will croak "soon" because SLA batteries supposedly have a life of 300 charge cycles (or so) and every time I ride the Lectra to work it is two deep charge cycles and while I haven't been keeping count it's likely the pack I have has 70-100 charge cycles in it right now.

The Lectra has a funny battery compartment geometry. It was originally designed as an electric motorcycle so the area that would normally be a rounded off motor cage is actually a squared off battery compartment. It has two trays each 15x15 inches with approx 7 inches vertical space in the lower tray. Additionally there is a space within the frame behind the battery compartment where I have stashed a pair of batteries. This space is 10 inches wide, 6 inches deep, and 15 inches tall.

Alternatively there are options like the GPR-S or Xtreme 3500li .. where I could get a lithium ION based motorcycle much more easily through an outright purchase rather than locating a suitable pack for my Lectra. Despite what I said the other day about Xtreme's shipping policies, it does appear they're delivering solid bikes that people are enjoying even with some of them arriving damaged.

One result I'd like with the Lectra is a higher voltage. 60v gives me a 47 miles/hr max and I'd like "more" and 72v ought to deliver "more" and I can do that with very little change in the bike. My current pack is 60v in 5 paired batteries meaning that the current pack could be reconfigured as a 120v pack but would mean a new controller.

LifeBATT:-

Their 12v20ah battery is exactly the same footprint as the batteries I'm using. 10 of them at $470 == $4700 (minus this current special discount offer) and it's not clear what to do about chargers. It's also not clear from their site whether these batteries can be connected in parallel. My lectra currently has 10 batteries where they are arranged as 5 pairs of batteries. In any case this would be 60v40ah or slightly less rated capacity than I have right now. This could also be arranged as a 120v20ah total pack.

Their 36v20ah battery is enticing. I could fit four of them in the main trays for a 72v40ah pack. $3500 for batteries. It's again not clear whether their batteries can be parallelized or what precisely to do about chargers. Similarly the 72v10ah pack is the same size and considerations.

Their 48v20ah battery might be possible to fit in the Lectra. Same discussion. Their 96v10ah pack has the same shape and could be interesting except it absolutely would require a new controller. These might also require some frame modifications such as removing the central tray to make one battery compartment. 96v40ah total sounds enticing but I think the total cost would be over $8000...!!!

I don't quite understand the pricing .. 48v20ah appears to be the same battery as 96v10ah (same number of cells, just a different cell arrangement, but at a $120 higher price.

Headway:-

Doesn't have several bits of important information posted on their site such as size, weight or cost.

They have 12v 30ah and 48v 20ah battery packs available. It's not known whether these will fit in my Lectra. The discharge ratings are a bit less than what I'd need in the Lectra. However they're really set up to sell to dealers rather than sell to individuals. There is a group purchase operation happening http://tech.groups.yahoo.com/group/lifepo4-purchase/ and I think Joshua has said the posted prices will change in the future.

Elite Power Solutions:-

Is selling packs made from thundersky batteries.

They sell a 60 ah 24 cell pack that looks interesting. Nearly $3000 cost. Each cell is 8.78X4.69X2.49 in and I haven't mapped it out completely but I could probably wedge these into the Lectra. The cost doesn't include a BMS and they do carry a BMS which appears to cost $1700 and then some more for a charger.

I'll have to double check on this but IIRC someone on "V" set up a bike with thundersky batteries and a different BMS.

Tradwin:-

Is also a thundersky distributor .. they don't have many specifics on the site but offer complete packs, BMS, charger, etc.

Electric Motorsport GPR-S or XM 3500li or waiting for the next model Vectrix or purchasing a current model Vectrix ... Any of these would get me on a higher speed longer range motorcycle with less trouble and maybe less cost than rejiggering my Lectra.

I ordered two new 20Ah LiFePO4 cells from Sam at Yesa on Tuesday to replace the two that were damaged (see "Fire is Bad"). Cost was $70 per cell and shipping from Hong Kong was $45. The cells arrived last night along with an individual cell charger. Sam asked me to send him a picture of the cell arrangement in the pack so he could have the tabs soldered in the correct orientation.

The red arrows indicate the bad cells.

Yesa's website gives pretty good instructions for replacing cells in a battery pack. I will apparently need use the single-cell charger on the new cells to adjust their voltage to match the older cells before the BMS can take over. I've also got some other fire-related damage to deal with, like replacing one of the charger wires with melted insulation, and finding some HDPE sheets and building a case for the repaired battery pack. Unfortunately my work schedule will probably not allow me to get this done until next weekend or later.

I took my damaged pack over to Synkromotive today to have some experts take a look at it. We took voltage readings of each of the 12 cells. They each read about 3.3V, except for two cells. One of them read just about zero, and the one with the obvious damage read about 1.8V. Their advice was to just replace the bad cells and keep going. They also briefly studied the BMS that came with the batteries, and deemed it satisfactory.

So now I just need to email Sam at Yesa and get a couple new 20Ah cells, install them, then replace the charger wires with the melted insulation, and I should be good to go. After I build an insulating case for the battery pack....

Can anyone recommend anyplace that recycles lithium?

Jake

I had a harrowing experience yesterday while I was riding the Rezistor home from work. I smelled something funny (it always starts that way, doesn't it?), looked down, and saw smoke coming out from under the seat. I pulled over, cut the power, got off, and saw the paint on the exterior catch fire. I blew out the fire, lifted the seat, and saw some arcing between the corner of the battery pack and the inside of the scooter body. I disconnected the battery pack immediately. The pack fits pretty snugly, so it's not too easy to pull out, and I kept bumping the corner of the pack, causing more arcing and reigniting the body paint. I eventually managed to stick some insulating material between the battery and the body, pull out the battery pack, and ride home on the remaining battery pack. Fortunately, none of the smoke was of the "magic" variety, as everything else seems to still work.

What had happened was the corner of the pack had been rubbing against the scooter body and eventually wore through the outer casing. When the battery innards came in contact with the metal of the body, they shorted and arced, producing plenty of heat to vaporize the corner of the cell and ignite what paint was left on that area of the body.

Let me emphasize that the batteries themselves did not catch fire. The damage was caused by my own failure to properly secure and insulate the batteries within the vehicle. The LiFePO4 battery pack appears to have remained very stable, and the other pack was fine. I plan to contact Sam at YESA to see if I can buy a single 40Ah cell to replace the ruined one and try to get the pack back in working condition.

So here are the lessons to be learned: Secure your LiFePO4 batteries so that they can't move around inside your metal scooter body, and cover the battery pack with a tough insulating layer.

A few less dramatic issues to report: A couple of weekends ago I paid a visit to Synkromotive, a company not too far from my home that develops controllers. I met frodus (Travis), one of the guys who posts here, and he showed me the current state of his eVFR conversion (nice!). I also had some excellent conversation with the Synkromotive folks. It was nice to have my project looked at by some people who actually know what they're doing.

Sometime during my visit, the fuse to my 12V converter blew, so I went home and replaced it. I started riding again and almost immediately noticed an smell reminiscent of cigarette smoke, so I shut down and pushed the bike back home. I checked my 12V converter, and it no longer appeared to be converting - I had 36V running through all my auxiliary systems. This resulted in burning out about a third of the LEDs in my headlight (although the taillight LEDs were all fine). I bought two of these nonisolated converters from TS Motors and this is the second one that has failed. Frodus helped me find a new 12V (isolated) converter on eBay for about $30 and it seems to be working fine so far.

I knew that I had a short in my system somewhere, and I suspect that's why the converter failed. After hunting around, I finally found that the postive terminal of the battery pack under the left cowl was coming into contact with the battery rack. So I cut apart some cat-litter containers made of HDPE and made an enclosure for the pack to keep it from contacting any metal parts. That took care of the short. I suppose I should have done that for the other pack as well...

Also, I finally bought an LED-compatible flasher module and installed that last week. My turn signals still aren't working quite right, though, so I've still got some wiring to check. I've started working on license plate illumination and backup lights for reverse gear.

The two 36V 20Ah battery packs arrived yesterday. Pretty fast shipping, considering they shipped from China on Thursday. (sunglasses in the photo are for scale) Sam at YESA was able to have them configured two different ways so I can fit one (barely) where the gas tank was and the flatter one in the left cowl. I think I'll separate the BMS circuit boards and put them in the gas tank area where they're better shielded from the weather. The chargers (one for each pack) were a little bulkier than I had hoped, but they're light and I think I can fit them under the seat, where I'll also include the charging cord.

Thanks for the advice about checking the individual cells. The only real instrument I have right now is an analog multimeter; will I need more than this to check if the BMS is working properly?

Jake

Altair Nanotechnologies Inc. has received a $1-million purchase order for NanoSafe 35 kWh lithium-ion battery pack systems from California-based Phoenix Motorcars for delivery in February and March 2007.

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