I don't want to put a damper on the work these guys are doing on ES but if i remember correctly they have been working on that BMS for a long, long time now. I sent them a PM a long, long time ago asking for a cost est, because at that time they thought they were really close to finishing. I nevr heard back from them. I think that was sometime around Xmas. So I hope they succeed and do very well with it but I wouldn't bet the farm on in the near future.

Well, there are at least two other options. I saw the Doctorbass video where he built the thing for an e-car and another video where the beastie I had hoped to use was running. I know he got a load of boards, and that there was an issue with one of the circuits. I have to admit, Fechter can run rings around my electronics background, but I bet I can work something out when I'm ready.

I've used this to go to work two days now at -3 (celsius) and back and the charger combination is clicking nicely with careful supervision and manual cell balancing. The 36v charger is doing well, but it needs a cell "top off" every couple of charges to make sure things don't wander too far into the "red zone."

I'm one of those people sho are always "lucky" in that Oprah's definition of "Luck is opportunity meeting preparation" applies. "Always be prepared" - Boy Scout motto....

Careful not to charge the lifepo4 in the cold. I read that you can charge them in the freezing cold and think you got a full charge when you really didn't.

The only thing BMS's are for are the consumers who just want to plug it in and not worry about it. Enthusiasts like us can navigate around those things. The only thing that is really absolutely necessary with Lithium is a Low Voltage alarm and that's only if you want to use the entire pack (which most people do). If you know what you are doing, a standard BMS really isn't necessary. The electricity does flow through all the cells. The people making the BMS try to pretend that the electricity doesn't flow through all the cells. Well, that's nonsense. As long as you don't have a charger that takes past the high voltage threshold, it's fine. You just have to find a way to top them off every now and then.

Where I go, the batteries go. It's a little wierd and I'm kinda getting used to it. They don't spend much time in "the cold" - I bought gloves today. One of my "exploration rides" last week took me over 3 frozen waterfalls - I walked over them instead of risking a dump. Wind resistance and "assistance" is significant here. Let's say that I've easily gotten windburnt over exhausted, and I do pedal on hills and such. It's threatening to snow, so the bike is shelved for a couple days.

My coworkers are fine with it as long as I don't charge at the office (they saw the videos.)

I'm beginning to see the limited value of a BMS, and after today's ride, I'm going to up the LVC to 34v from 33 for the pack. The serial charger is working fine without much help and I'll be able to finish the longer-range batteries shortly. I think I can outwait the production of the "BMS of choice" - but I wouldn't recommend that everyone try it.

As for the regen issue - I sorely missed the regen braking today going down some hills. At the very least, it saves on pads and the batteries bouncing all over. I was being careful, but could have let it go - and then I got passed by two police cars at the local ski hill. (Calgary Olympic Park).. I don't think that energy recpture is its strongest point, but then I still have yet to hit the end of the range on my 20Ah set...

BMS's are just kind of substitution for laziness. Most consumers don't like reading instructions.

Morph,

I think you would agree that monitoring discharge and charging is critical, especially for lithium batteries. Yes, most people want automatic monitoring and that's not laziness, it's caution. Fortunately, there are now some more affordable alternatives for automatic monitoring available than just computerized BMS boards. I have a CellLog 8S on my new TS LIFEPO4 pack. I use the audible alarm feature to warn me when the battery is charged as well as when any cell is discharging below 2.7. I don't have electric brakes, if I did, I could actually wire the CellLog 8 to function for LVC. The newer, less expensive CellLog model doesn't log, but it does monitor cells during charging and discharge and it's price is dirt cheap. There's now no excuse not to have automatic monitoring for your LIFEPO4 pack.

Here's how I've attached the CellLog to my pack (I have the Currie conversion kit installed on my bike and the battery case slides into the side rack--I've now got my original SLA and the LIFEPO4 pack for power).

The argument for a cell monitor is well noted. My Cycle Analyst has a Low Voltage Cutoff that will cut off all power at a certain level. I've not had any problems with cell balancing after the initial top-up, although I do manually balance the cells once a week anyways. Since I have it set to go at 34v (2.9v * 12 cells) it will generally catch any issues - although I would hate to be out in the middle of nowhere if it were to go off.

I would gladly trade the hours of manual finicky stuff to be lazy really, but this learning experience has been invaluable. It helped build "trust" in the system - knowing how far I can go and just how far I can push the system. I'm gradually expanding my range and testing different routes to maximize range by reducing hills and other wasteful practices. I'm pedalling more when it counts and watching the consumption of power to try to minimize draw to extend range.

I did check into local suppliers for balancers, monitors and chargers - it's much more effective to order offshore (a 2 pack 6S LiPo charger here is 400, a simple 8 cell balancer is 110) and as impatient as I am, I'll wait a little longer for the goods to arrive and save tons of money.

BTW - nwmtnbkr - great job on the cases...

Just got back from a 40km (25mi) ride, used 15.75 Ah and the cells were all at 3.23v, I'm bulk charging them now. Still haven't gotten the regen fixed, looked like I was right when I figured the jumper I soldered in on the controller wouldn't cut it.

Sigh - off the buy more Artic Silver for the heatsinks when I pull it apart.

I hope you haven't lost sight of the main reason for a cell monitor. You indicate you have a CA with a LVC but it only looks at the total of your pack. Therefore, your total pack voltage could still be fine but 1 cell has a problem and drops low while under heavy load and you won't know it. Also remember that all batteries have an "at rest" voltage but it is not the same under load. So it is a false assumption that all is fine just because all you cells are 3.23v when you are checking them "at rest". I am not saying that this is a bad thing but don't be fooled into thinking the cell monitor while riding is not worth having.

I always check the cell voltages before and after charging and before the ride. Any time there's an issue, I top all cells to within about .01v of each other. (They sit for a while after charging before I test them) For now, I think I'm fine riding without the cell monitor, but I am always checking draw, voltage, Ah used and such during the ride (Cycle Analyst)... Over the long term, cell monitors and a BMS... I am not going to sit here and look at a bike and wait for the rest of the stuff to arrive as I can afford it.

Had a few issues with the bike - strange noises from the rear, regen stopped working, needed to waterproof the connections and then a pedal fell off - turns out it was stripped. The bike got ripped apart again so I could fix it up.

The regen issue was clearly going to require pulling the controller apart as I had tested everything else and it passed. I had used Arctic Silver, a high quality CPU heatsink grease - bad choice. That stuff turns into cement over time. I ended up drilling out two of the bolts and then had to use a lot of force, removing a lot of skin from my knuckles in the process, breaking a few internal connections (throttle override, a ground wire and the on/off switch connections. I was going to have to open it again since I wasn't happy with my original modding effort.

I have an Infineon controller, so thankfully I figured out that I could use a Radio Shack diode, located where the original had been soldered onto the board, traced it back and found a pad labelled "SL" that I could solder the new diode through. Lots of good technical info on the controller online. Soldered the ground and power lead back onto the board, removed and resoldered a better jumper for the regen and mangled the rubber seal on on side. Finally got it back together and re-sealed it with Silicone.

The regen issue turned out to be a broken wire inside a connector, so *snip* *solder* and a little heatshrink tubing solved that one.

Connected the batteries, powered it up and it looks like I got it right.

The noise turned out to be some of the spokes had come completely undone. Screwed the caps back on, checked the true of the wheel and used a little loctite to ensure they never move again.

Replaced the front crankwheel with a Shimano kit I bought and now I'm nursing a sore finger and wishing I had never taken the front derailleur off. No matter what I do, I cannot make it work. Tried what they said in Youtube, but no luck. Thankfully the bike shops are open tomorrow, maybe I can go bribe someone to make it work for me.

It was a beautiful day here and I had hoped to get a 30mi ride in but that was just not in the cards.

EDIT...nevermind. Definitely avoid going below 2.5v even with voltage sag. There is still a lot not known about lifepo4 but to be on the safe side avoid any sag below 2.5v.

Yeah, today was spent aligning the front derailleur, turned out to be the bottom bracket - that was an epic battle, but Shimano won.... I measured the original bottom bracket at 124mm and bought a 113mm Shimano to match the crankset. It's finally all installed. If I had gone to a shop, it would have been weeks before I got it back.

Now that it's all back together, off to see if I fixed the regen. And get ready for tomorrow's commute...

I ordered a new controller, throttle and brake today. I now has a magnificent pedal bike that works fully. I am just too lazy to pull the tire, tube and freewheel and put them back on the old rim. I did order 2 of the better CellLog monitors - mostly because there were so many of the "deluxe" ones in stock and none of the ones I originally wanted. They will work famously.

One thing I learned is that I am not gentle and once you have it working, don't mess with that part. Change is not always good if handled roughly. I needed spare parts anyways - and things to experiment on, but not everyone wants those. Still, they can sit for a few months while I cool down at my own stupidity.

Oh, I remember why I shelved the old "Daily Driver" - I knew it was stripped and stuff. I just never had the tools to replace it. *Packrat*

Hey new (hope ya don't mind, it's much shorter...) Is that an small IPOD case around yer cellLog?