milwaukee v28 cable how to video

[Jay64]

Oops, I meant 5 lbs! The stock battery was 15 lbs. Sorry, my bad.

 

[1800vtx]

I couldn't restrain myself, so I went ahead and bought the first of 12 packs

If nothing else it'll allow me to get started on figuring out the size, weight (with my scale ), and location(s) to place the packs on my bike. I'm also going to put my order in for the mounting adapters before the price of those goes up

Lastly I'll be purchasing the disk brake for the rear of my bike to replace the v-brake setup.
Then its a waiting game till next payday

 

[pwbset]

first of 12 packs

You're nuts man! And that's a... good thing!

 

[1800vtx]

first of 12 packs

You're nuts man! And that's a... good thing!

Can't just stick all 12 on the back end, got to distribute the love

Yeah, I've been getting that a lot lately, "12 packs, ain't that a bit much for your wee bike?"

If it wrong, I dunna wanna be right 8)

 

[Joey]

I just assembled a 3s2p Milwaukee 28V Li-Mn pack on a bike with an EV-Tech BMC rear hub motor, and Crystalyte 72V 35A analog controller from ebikes.ca. The batteries and chargers are brand new and were all purchased at the same time. I made a few test runs two evenings ago and everything worked beautifully. I then rode the bike into work (7.7 miles) the next day, taking it easy since it was downhill and I wanted to conserve capacity for the uphill return trip. My bike was parked outside all day at work and the outdoor temperature hit 94 degrees. The batteries were in a black rack trunk bag on top of my rear carrier. I left the batteries connected to the controller but the controller power button was off. As I left work that afternoon and travelled about 100 ft or so on level ground, power dropped suddenly and I had to rediscover the pedals. The CA display showed a combined pack voltage of 43V. It had showed over 52V after arriving at work that same morning. As I pedaled home, I switched on the controller occasionally and observe the CA display. After a few times, the display started showing random characters, and eventually went dead.

I was wondering what might have caused this problem. When I got back home, I put the batteries on their Milwaukee chargers and they immediately showed 3 LEDs on indicating that they had not lost more than 1/4 of their charge. After reaching full charge in minutes, I connected them back up on the bike and went for another test drive. Once again, everything worked beautifully. Do you think the problem was thermal? Does the red button on the Crystalyte controller power off everything, or does it still draw some power even when this switch is off? What else could have been the problem?

-- Joey

 

[1800vtx]

I just assembled a 3s2p Milwaukee 28V Li-Mn pack on a bike with an EV-Tech BMC rear hub motor, and Crystalyte 72V 35A analog controller from ebikes.ca. The batteries and chargers are brand new and were all purchased at the same time. I made a few test runs two evenings ago and everything worked beautifully. I then rode the bike into work (7.7 miles) the next day, taking it easy since it was downhill and I wanted to conserve capacity for the uphill return trip. My bike was parked outside all day at work and the outdoor temperature hit 94 degrees. The batteries were in a black rack trunk bag on top of my rear carrier. I left the batteries connected to the controller but the controller power button was off. As I left work that afternoon and travelled about 100 ft or so on level ground, power dropped suddenly and I had to rediscover the pedals. The CA display showed a combined pack voltage of 43V. It had showed over 52V after arriving at work that same morning. As I pedaled home, I switched on the controller occasionally and observe the CA display. After a few times, the display started showing random characters, and eventually went dead.

I was wondering what might have caused this problem. When I got back home, I put the batteries on their Milwaukee chargers and they immediately showed 3 LEDs on indicating that they had not lost more than 1/4 of their charge. After reaching full charge in minutes, I connected them back up on the bike and went for another test drive. Once again, everything worked beautifully. Do you think the problem was thermal? Does the red button on the Crystalyte controller power off everything, or does it still draw some power even when this switch is off? What else could have been the problem?

-- Joey

Hey Joey,

See the top of page 3 of this post.. pwbset describes an issue with the batteries BMS (rated at 55V) when trying to go for a series of 3 (its the reason I'm going with a series of 2 myself).

Consider yourself lucky, one guy joystix2 tried that kind of setup and ended up with a bunch of smoke!
He now uses a 2 series as well, and although its not as high a voltage, his Clyte 405 (on a 20" wheel) gets into the low 30's speed wise.

If you don't mind bypassing the BMS and voiding the warranty (5 year/2,000 charges) to get your 84V, go for it. But most of us went for this setup due to its ease of assembly and the non-need to open the packs or do any custom soldering.

Good luck

 

[pwbset]

If you don't mind bypassing the BMS and voiding the warranty (5 year/2,000 charges) to get your 84V, go for it.

You can indeed leave a 3s2p pack build in tact with warranty in place if you solder some diodes inline on your assembly blocks so if (more like when) your battery pack BMS trips the diodes conduct and protect the pack (see fechter's thread in EV Basics on BMS protection ). I've been riding 3s2p all week at 84v and maxing my 20A controller and it hasn't been an issue at all so far. If my pack BMS are indeed tripping it's so fast to recover that I'm not noticing it. 84v is a kick in the pants needless to say. From everything I've read/heard these Milwaukee packs are individually rated to 55v and 20A each so 2 in series is fine "out of the box" (at least @ 20A), but 3 in series needs the diodes for protection. See this thread for details and photos of the diodes --->

http://endless-sphere.com/forums/viewtopic.php?f=6&t=4716&st=0&sk=t&sd=a&start=30#p72912

What's your max Amp draw on the Cycle Analyst? I bet your 35a controller is tripping the pack BMS, in which case you are indeed lucky the FETs haven't "puffed" on you.

Do a member search on mlrosier, jondoh, maytag, lazarus, joystix2 etc. etc. They all had the builds that I poached from to build mine.

 

[pwbset]

It had showed over 52V after arriving at work that same morning.

If pack voltage was 52v at the beginning of your ride you weren't 3 in series, but only 2. 52v is consistent with a 2s that's near a full charge or under load. "Hot off the charger" in 3s is around 87v. You may have wired your setup wrong. Got pictures?

EDIT: You should probably start your own thread under Photos&Videos so we can track your build there.

 

[1800vtx]

You can indeed leave a 3s2p pack build in tact with warranty in place if you solder some diodes inline on your assembly blocks so if (more like when) your battery pack BMS trips the diodes conduct and protect the pack (see fechter's thread in EV Basics on BMS protection ).

Whoop! You're correct sir! I glanced over that little tidbit (you'd think I'd remember after reading about it this week)

This 'work around' can allow you the 84V you seek without voiding the warranty

Shoot, I might just reconsider my 2 series

 

[paultrafalgar]

I'm sure you've all thought of this, but, in case you haven't...
If you're only interested in extra range, rather than speed, why not stick with the 2s2p arrangement, thus avoiding the complications of 3s2p and carry the extra 4 batteries and swap them with the others when those get exhausted?
Or have I missed something?

 

[pwbset]

If you're only interested in extra range, rather than speed

I chose 3s2p because I have a rear 4011 and need to climb 1,600ft over 3.5mi every morning to get to work and at 56v the 4011 is okay, but at 84v it really shines and pulls hard at lower amp levels. Having the ability to burst up to 30mph through traffic helps to.

I do like your idea of just having some spare packs in a backpack and swapping as needed for long trips. Gotta save some money first! Batts are getting expensive!

 

[Joey]

Darn, I meant to say 2s3p (56 volts) when I mentioned my problem. I still need help.

-- Joey

 

[pwbset]

Darn, I meant to say 2s3p (56 volts) when I mentioned my problem. I still need help.

In that case I'm not sure, but maybe it was the heat. If the batts were in a 94 degree ambient sealed in a black bag that's kinda hot, but I'm sure within the operating limits. Was the controller in the bag too? Controllers like to breath fresh air. Have you triple checked all your wires and connections for possible shorts?

 

[Joey]

The batteries are in a nylon trunk bag on top of the rear rack. The controller is mounted separately on the front portion of the rear rack on a downward slope toward the seat post. The controller wires and power button are toward the seat post end.

I checked the wiring when I got home with an analog VOM. There were no shorts and good continuity where it is supposed to be. I have a 30A fuse on the positive side of each 2s battery pack section. The fuses are Ford automobile style and securely snap into a 6-to-1 fuse block. The single output of the fuse block goes to the controller. The negative leads are tied together on an insulated barrier strip, and the negative common goes to the controller. All of the connections were tight and secure. There is a pair of Anderson powerpole connectors in-line to the controller. Both the fuse block and barrier strip are mounted solidly on a plywood sheet using nylon screws, and all connections are covered with heat shrink. The fuse block and barrier strip assembly fits nicely in the pouch at the back end of the nylon trunk bag. There were no blown fuses.

Update: I just went for a lengthy test ride and deliberately ran the batteries until they sagged to the point where they began to fall off sharply (somewhere around 39 volts). Everything worked normally. I probably should not have let the batteries get that low but I wanted to observe the system behavior to know what to look for when I'm about to run out of juice. I'm beginning to think my original problem was thermal.

P.S. What would be a good LVC value to set my Cycle Analyst at for this 56V pack configuration?

-- Joey

 

[pwbset]

P.S. What would be a good LVC value to set my Cycle Analyst at for this 56V pack configuration?

Looks like you're figuring it out through self diagnosis!

Are your Milwaukee packs in tact (if you're resting voltage is 39v it sounds like you bypassed the BMS of the packs)? If your packs are in tact you can just ride until they hit their own LVC at around 23-24v a pack... so like 46-48v... they will just shut off and wait to be re-charged with a single blinking LED. Of course you'll see dips below that under load etc., which may explain your 39v, but my 3s LVC trips around 70-72v resting. You'll likely not be able to ride more than 7.8-8ah before your pack shuts off so keep an eye on that also.

If you bypassed the BMS you can take these cells as low as 3v per cell or 21v per pack without damaging them in the slightest. So set your Cycle Analyst to 42v and you should be totally fine. They are spec'ed as low as 2.5v operational, but that would maybe shorten the life span.

Hope that helps.

 

[Joey]

Hi pwbset,

I am using my 28V Milwaukee packs intact, so I assume the internal pack BMS's are working. I did notice that after the bike ride when I let the 2s3p pack voltage get down to about 39V as indicated by the CA, and then put them on the chargers, they indicated one LED blinking. From your comment, I take that to mean that the LVC in the BMS's did in fact trip. Is it better to let the Milwaukee pack BMS LVC trip or is it better to set the CA LVC at a higher voltage, e.g. 42V as you suggested, so it will trip first?

-- Joey

 

[pwbset]

Is it better to let the Milwaukee pack BMS LVC trip or is it better to set the CA LVC at a higher voltage, e.g. 42V as you suggested, so it will trip first?

Dunno really if there is a better way. I just let the pack BMS trip so I don't have to worry about the CA settings.

 

[1800vtx]

If you're only interested in extra range, rather than speed

I chose 3s2p because I have a rear 4011 and need to climb 1,600ft over 3.5mi every morning to get to work and at 56v the 4011 is okay, but at 84v it really shines and pulls hard at lower amp levels. Having the ability to burst up to 30mph through traffic helps to.

I do like your idea of just having some spare packs in a backpack and swapping as needed for long trips. Gotta save some money first! Batts are getting expensive!

Damn!.. and here I was going to go with the 56V route!

I'm going to see how you're setup is doing in a couple of months, by Sept. I should be getting ready to put my pack together.
If your pack is still holding up, then I'm saying chao to the 56 pack and going with a 3s4p 84V pack

Until then, I'll be watching for any BMS issues vicariously through you and others with this setup!

 

[Jay64]

I have a pretty full set of Milwaukee 28v power tools, sawzall, skill saw, impact, hammer drill, flash light. I used to do some construction work with them and would rutinely run them down till they stopped and then switch out the pack for another one. I never had a problem with doing that. I think the problem with the battery that I just killed was because I had ran it all the way down, and then didn't charge it up for a very long time. I switched jobs, and hadn't gotten into this EV stuff yet, so I didn't have a use for it being charged and forgot about it. It was probably in that depleted state for at least 5 months. My point being, from my experience, I don't think there is a problem with running them down until the bms cuts them off, as long as you recharge it in a reasonable time frame. A lot of times I would wait a day or so before I would recharge them.

 

[pwbset]

I think the problem with the battery that I just killed was because I had ran it all the way down, and then didn't charge it up for a very long time.

What's the volt reading on your dead pack? I bet you could do the whole on/off/on/off the charger thing like 100 times to trickle it back up to where the charger will fire it up again.

 

[Lessss]

Bump, None of the vids in this topic seem to be working anymore.