Bosch 36V fatpacks opened up

[aaronski]

Did you revive the two pack from the CA mishap?

All fixed. the Soniel charger has a deep discharge state charging feature that brought it back up. put 4.4 ah in it. seems to run the same now as before, but I fried my throttle hooking up to an alternate controller, it had switched vbat and 5v pins... I'm just pedaling my 55 lb monster now...

 

[jkirkeboe]

I know everyone says not to split the packs but as I needed a very custom shape and 48V I had no choice. So I did this:

Opened the packs and cut open the red plastic. No need for a dremel, a sharp knife removes the plastic in 10 seconds.
Separated the cells in packs of one or two by cutting the tabs. I bent the tabs over and added solder.
I then glued the cells together with a LOT of hot glue. 12 gauge cable was tinned and soldered to the pre-tinned tabs.
I the added a lot of hot glue on top of the battery (well, both sides) as well. The pack is very solid and with almost no chance of anything shorting out, even in a wipeout. But it is also close to impossibly to swap out a cell....
Around the pack I added bubble wrap and duct tape, and a 60A fuse from one of the fatpacks.

The resulting pack is 48.1V and ~11Ah, 13s9p configuration. 54.6V hot of the charger (will adjust this down to 53.3V).

I have ordered a custom in-frame bag from Epic design, awaiting this I mounted the battery with duct tape for the time being. The bike is fitted with the Ezee kit from ebikes.ca, and Cycle Analyst.

Speed on the flats with NO pedaling: 25mph(!)
Moderate effort pedalling: approaching 30mph.

The pack never went below 50V. I'm very happy with the results!

So, one can quite easily split these packs if one needs to for whatever reason. I used two evenings to build the pack. The pack is just under 10 inches tall, 12 inches long and a little over 3 inches wide. Weight 12 lbs, complete bike 45 lbs.

I knwow it's not a "clean looking" battery build, but it works. Quick and dirty

Pictures:

View attachment 3




BTW: This is a crap seat, not the one I normally use.

 

[pwbset]

:lol: Nice! Glue, solder/copper, duct tape. Looks all too familiar to me. :wink:

 

[nineball]

I started to make this nice 3 pack holder out out 1/4 luan, notched to slide on the pack, with contacts made from copper pipe, and then cut slots in a board to fit it all together. 3 packs per.

Then...i just took a 10g (yellow) ring connector, (small, 1/4 or so), and soldered the hole closed, and filed it so it would slip in the pack contact. Slipped them in, taped them in, and just did the same to more packs, and soldered the wires into a harness between packs. All I did was make the next one a little longer, cut a section of insulation out of the first one, and soldered the second one to that, and the same for the third.

To hold the bare sections together while soldering, I wrapped them with some 22g telephone (skinned) wire.

Then I just taped the 3 packs together. (I think I blew a fuse in one, so using 2x2 now)

So now I have (or will soon, 2 now), 3 packs in parallel, per side (panniers), 6 total, with on board 36v charger..PLUS. my 4 12v sla (48v) with it's own charger (haven't built the 2 48v headways yet). 84v..about 100v hot off charge. Leme tell Ya...this thing fuking flys now...I'm luving it...

Same set up I've been running 12v A123 packs (60v total), swapped them out for the 36's.
Had to swap out the 30 amp switch, and relay for 50a versions, and put a 30a breaker in place of the fuse I now blew twice. Pullin some C's now

 

[nightowlgk]

Well, I just ordered everything. Thanks for all the help here!

6 Bosch fatpacks from eBay (Toolsteal)
Tenergy 13S Li-ion charger from All-battery
Ezee rear kit with pedal sensor, 9-speed frewheel, left side half-throttle and Cycle Analyst from ebikes.ca

It's my understandig that the Cycle Analyst will do both LVC and current limiting.

I'm looking forward to putting all this together 8)

Looking forward to a review of this combo........

 

[nightowlgk]

OK, Green light went solid.

Just measured all packs. Pack 3 (not connected to middle plug, but paralleled to the others) is 39.1. The one I had the middle plug into is 40.1.

Not a huge difference, maybe but I think I need to connect all the middle plugs for even charging.

 

[docnjoj]

Hmmmmm..........I only have the +/_ terminals connected in my 4 pack // system and they all read 40.6 after overnite rest from the Bosch charger. I think the middle terminal is for contact with the charger cut/in. It won't charge without 1 board connected.
otherDoc

 

[icecube57]

How would my charger respond if a put a diode on the output. Im expecting a forward drop of about 0.7v which would put the charging voltage at 41.3v. Would this cause the chargers to keep charging until it sees 42v or would its stop 0.7v shy of 42.

 

[nightowlgk]

Success, and 1st charging weirdness.

I stripped the loose end caps and trim off the packs and mounted them in a simple, white pvc gutter " tube" from home depot. I cut it and expanded it so they slide right in. Then is straps in the triangle to the lower tube. I hearby copywrite it, "The Torpedo". Pics to follow in a couple of days.

I paralleled the 3 packs and used one Charge plate with a +/- pigtail to charge the pack.

Used 5.9 Ah / 15 miles with a few long hills and lots of pedaling on my first ride to 32.5 LV and still going but slow. Then came in for its first charge which I baby sat in the garage. After about 45 min. the charger got warm, the fan and red light came on and it shut off. I guess this is the thermistor on the charge plate. I let it cool a minute and then plugged it in for a full 1 &1/2 hr. charge to 41.0v.

I'll check it out in the morning and ride again tomorrow.

 

[Sagz]

So... excuse the stupid question. I've very new to the whole battery thing. Are there 20 Cells in these packs?

 

[Russell]

So... excuse the stupid question. I've very new to the whole battery thing. Are there 20 Cells in these packs?

Yes

-R

 

[Sagz]

Wow so a quick autocad drawing later and this could be the way I go..

I like the idea of hot gluing the pack but I'd still like to be able to swap a cell out. I thought about gluing one side to a plastic plate and then shrink wrapping the rest. Any thoughts?

oh this would be 13s9p for 48V

 

[pwbset]

Any thoughts?

Yes, keep the packs in tact. :wink: Seriously though... as one who has taken apart and put back together 100s of these cells in all kinds of ways I've ditched all that and am getting in tact packs. Life is too short to be monkeying around with loose cells all the time. I've only ridden like half the mileage of last year because I've lost so much time to tinkering with stupid batteries. Fun, sure. Learned a bunch also, but still, for me, in the end if I'm not riding I'm not accomplishing what I set out to do with ebiking in the first place. YMMV. Good luck, post pictures. Etc.

 

[etard]

OK so who has the best intact pack setup on here?

As PWBST said, these are fun packs to keep as they are, maybe even show them off. Anybody painted them all black? Or what about a chrome spray on the cooling fins? Any ideas on how to customize them??

The reason I ask is searching for heatsinks for a powerful LED light, I came across this monstrosity on ebay. It got me thinking that hiding batteries would be cooler if you put it in a cooler. :wink:

Can we do something like this with the Bosch? Ideas welcome....

 

[yoyoman]

ah, now that this thread is moving towards the intact setup, I'd also like to ask how are you binding and wiring them?

I have been looking for a narrow container that I can use to hold the batteries standing up. I would also like to add something to my wires to make sure the +/- can never touch. I was thinking of using a flat piece of wood and poking the spade connectors through at the proper spacing so that I can just drop that as a whole onto my lineup of batteries.

Does anyone with intact packs have a good working example?

 

[icecube57]

I took the bms off drilled holes in the side covers. Ran the wires through the covers. Terminated them with the cheap 100pk insulated spade connectors. They stack pretty nicely. I ran a few healthy beads of liquid nails on top of the packs and stacked them 3 high. I let it cure about 3 days. They are not coming apart. They fit in my panniers. 6 on each side.

Or you can remove everything and wrap it in alabama chrome like i stupidly did on my first 6 packs.. You save a little over half an inch in width and height. You loose weight too.

Someone mentioned about doing a similar thing like did with my packs and putting the whole packs in a pvc pipe and bolting it to the bike some how. I thin a 5 inch pipe should fit one pack maybe. Slide them in 3 deep and put endcaps on them and drill a hole to run the wires out.

 

[jkirkeboe]

Any thoughts?

Yes, keep the packs in tact. :wink: Seriously though... as one who has taken apart and put back together 100s of these cells in all kinds of ways I've ditched all that and am getting in tact packs. Life is too short to be monkeying around with loose cells all the time. I've only ridden like half the mileage of last year because I've lost so much time to tinkering with stupid batteries. Fun, sure. Learned a bunch also, but still, for me, in the end if I'm not riding I'm not accomplishing what I set out to do with ebiking in the first place. YMMV. Good luck, post pictures. Etc.

I don't see the problem, really

I used two evenings to make my battery, which should last at least 2-3 years. Other work on the bike takes much more time...

 

[nightowlgk]

The "Torpedo" has been unveiled! Length DOES matter.

http://www.endless-sphere.com/forums/viewtopic.php?f=14&t=13037

Plenty of pics there.

 

[Russell]

It seems the price of Fatpacks is on the rise, there's only one seller on eBay offering them for $55 delivered with $78 being the next lowest (mine were $45 delivered a few months ago). I wonder now if the days of cheap Bosch Fatpacks for E-bikers is almost over. :|

One thing I really like about this LiMn chemistry is how easily it charges and then how it holds the end of charge voltage. For example if I charge my Fatpacks to 41.31V when I come back to use it the next day it's at 41.30V. My new 48V LiFePO4 battery on the other hand charges to 59.34V then falls from there so that the next day it might be reading 56.5V and 55V the day after that. Out on the road the LiMn Fatpack voltage falls steadily as it is used while the LiFePO4 quickly drops a few more volts as the 'surface' charge is burned off, then it stays exceptionally flat until dropping off at the end. I didn't realize there was so much difference between the two chemistries until I used them for myself.




-R

 

[icecube57]

I LOVE THE STAYING POWER TOO. IVE GONE A WEEK AND HAD A 0.03V CHANGE IN VOLTAGE. iT DOES TAKE A GOOD MINUTE TO BURN THAT SURFACE CHARGE OFF. WITH 6 IN PARALLEL ON MY 74V NOMINAL PACK IT SEEMS LIKE IT TAKES FOREVER. GOOD TIME TO SET SOME LAND SPEED RECORDS BEFORE IT DROPS OFF TO MUCH.

 

[aaronski]

sounds like fun. at this warning I bought 4 more packs, so I'll be running 3p2s. I have an e-crazyman controller on the way as well. we'll see what it's like moving from 36-72v...

 

[John in CR]

...we'll see what it's like moving from 36-72v...

Nice 6-pack. You'll never go back to 36v.

 

[ToughRowToHoe]

I have to say that Ice's photo shows me little space is gained by cutting the packs apart. Since the packs are virtually bullet proof together, there needs to be a large space constraint to make it worthwhile before pulling them apart. Sure hope the price isn't rising permanently.

 

[John in CR]

I have to say that Ice's photo shows me little space is gained by cutting the packs apart. Since the packs are virtually bullet proof together, there needs to be a large space constraint to make it worthwhile before pulling them apart. Sure hope the price isn't rising permanently.

That is not representative. With a minor amount of effort they can be made to stack together better resulting in a much smaller pack while still retaining the toughness of the thick red plastic sleeve. Sorry I didn't have backups of my in process construction pics when my hard drive crashed, but if I remember correctly I fit 4 in the height of 3 full packs. Plus there's length and width savings too. For example, my pack made up of 10 fatpacks is 11.5"x3.5"x9". I wouldn't toss it around like a toolpack, but I've knocked it over and dropped it with no ill effects, and it's far more water resistant that a raw pack.

John

 

[etard]

The price has gone up dramatically on these batteries! And now there seems to be some imposter off brand on there so buyer beware! Although the the seller seems to be All Battery, which I think is somewhat reputable. The lowest price I found was $100, and some sellers are selling them for $150!! Is the supply running out, or has the demand gone up? I hope I have enough. :?