Let the Ping surgery begin

[docnjoj]

Here are the first photos of my cuttin up a perfectly good 48v 20 AH Ping. I need to balance it on both sides of my trike and this seemed like the only way. Dnmun suggested that I use it's natural "cut zones" and make it( 2) 24V 20 Ah batteries. This really would be fairly simple. I would really like (2) 48V 10 Ah batteries connected but the amount of desoldering and reconnection makes this daunting. If anyone has "the easy way out" to make 2X48vX10ah please let me know. Otherwise I will get to extending the sense wires and the series connection. Thanks in advance! The ceramic knife really aided my confidence as it obviously cannot short anything!
otherDoc

 

[nicobie]

I had Ping split my 48v/20ah into two pieces so I could mount them in my saddle bags.

It looks to me that all you have to do is cut the big white wire in the bottom of the pic and that would separate the two halves. Then just add the length of wire needed in order to place the two packs where you need them to be. The same treatment will be needed on the sense wires on one half of the pack.

You would then have 2 x 24v/20ah packs wired in series and end up with a 48v/20ah battery. trying to get 2 x 48v/10ah would be kind of tough to do. I'd be afraid to try it.

 

[docnjoj]

Roger that, Nicobie. I just was wishfully thinking there was an easy way out! Oh well!
otherDoc

 

[Ypedal]

Sweet ! looks like a piece of cake ! split that sucker right down the middle ! 2 good rectangular blocks, one for each side saddle bag ! 8)

ymmv, but when i solder or wire up these things i try to work on the vertical instead of the horizontal so if you drop something it goes to the work bench and not on top of the pack.. take some tape and cover the tabs you don't need to work on..

Remember, clean work bench, no jewelry !! Tape your tools when possible, and i really like that ceramic blade... :?

 

[docnjoj]

Hey Gaston! If I could get my wedding ring off, well, I would. Prolly tape over it and wear rubber gloves. Good thought about working on the vertical. I will only do 1 wire at a time so that should help. 22gauge sense and keep the 12 ga power. The series jumper I guess 10 ga. Yep neet and tidy, I hope. Ceramic blade courtesy of

http://www.ceramicknife.org/

Cool guy and also from Canada.
otherDoc

 

[kilowatt]

I just finished splitting my Cammy 36Volt 20amp pack into two halves and Cammy used the cylindrical cells and spot welded bars throughout so I had to be careful not to lift a weld; I did lift several but solder fixed them. When I removed all the duct tape and cardboard I found two 18 volt 20 amp batteries series connected with battery bars. This made it pretty easy to separate the two. Cammy sent me the pinout for the BMS sense wire connectors so everything is tucked away in panniers and charges just fine. I too think the two 24 volt 20 packs is the way to go. Unfortunately, I couldn't get the photos uploaded for some reason. How do I upload a JPEG? I found a source for 9 inch wide shrink wrap is anyone is interested. TPpacks.com. They also sell a BMS kit.

kilowatt

 

[docnjoj]

TPPacks I believe is Gary Goodrums website. He has some cool stuff and I will check for the shrinkwrap. It does seem a shame, however, to ruin the ducktape finish! I am getting ready to do the deed, but way too much stuff has descended on me for Christmas. Family stuff unfortunately comes before bikes. Maybe later this week I can get some free time to operate and solder 8 wires. We will see. Have you noticed a problem with uneven leads to the BMS causing charging differences? Merry X-mas Bah Humbug!
otherDoc

P.S. Killowatt Jpeg should be fine if around 640x480. Upload thru the website and it works fine as attachments.

 

[nicobie]

Have you noticed a problem with uneven leads to the BMS causing charging differences?

On the split pack that Ping did for me, one of the sets of balancing wires is 30 in long and the other side is about 6in. It seems to balance fine.

 

[kilowatt]

Thanks for the Jpeg info. I want to change my sense wires to 22 gage; my battery is charging fine but I think the ribbon cable I spliced into the BMS cable is too thin a gage. Is 22 gage the norm for this? I have to splice because I can't find a like BMS connedtor anywhere to make a single cable end to end. I have one 8 pin connector and one 4 pin connector. The 8 pin holds 1-6 for the left battery half and 7-8 for for the right half with the 4 pin holding 9-12 for the right (6 channels each half). This makes extending the bms wires a challenge; I wish they had used one 12 pin connector but it is working.

Kilowatt

 

[docnjoj]

Okey dokey! Ping is separated and sense wires extended on one end (the easy one). I had to use 20 ga wire cause thats all I could get around here! I re-enforced it with a lot of shrink tube and I hope it works. We will see. I even taped my ring as I really dont want shocks from 48 volts! I also have a connector problem and that is only one 16 pin connector is used so I cant disconnect the two batteries once I solder the extended sense wires. I may make a trip to the hobby shop tomorrow to see what they have. Radio shack really doesn't have much but every once in a while they surprise me, The last surprise was the 22 Ga wire that they had was single strand, not so great for a bike situation. Here are photos.

View attachment 1
otherDoc

 

[nicobie]

That looks just like what Ping did on my battery. He also used 20 ga. wire and ran them through some thin yellow shrink wrap that he left un-shrunk so it's still flexible.

My Radio shack had 9 pin molex connectors in stock and that's what I used. However they are kind of big and I don't really trust them so I ordered a pair of 8 pin jst connectors that I'll put on in the future.

 

[StevenR]

I just cut the connector in half. It seems to work. I sorta melted the ends and it seems to hang together.

One more reason NOT to try the desolder-cells-and-reconfigure approach. The used cells tend to swell if not kept compressed, particularly if charged or discharged. I haven't finished the repair job I started because the whole thing swelled up when I wasn't looking (over a couple weeks). I cranked it together with a couple of clamps but I doubt the cells are any good anymore. Even so, I didn't get enough new cells to even replace all the bad ones I found before it swelled. I considered bad to be 15aH (75% of rated) and I had four packs between 10 and 15aH and two at zero. Lucky I ordered a V3 along with the new cells and a Headway from evcomponents. Now I think I will just pick the carcess like a hyena - find the good individual packs. Anywho, the two packs seem to be individually wrapped when you cut them apart so they should stay compressed. Perhaps it would be good to compress it further as the tape has probably stretched. Anybody know how much to compress the cells? I have seen reports http://www.endless-sphere.com/forums/viewtopic.php?f=14&t=13911&start=15&hilit=compression on how compression deceases internal resistance but I never saw any figures. The cells in a Ping v2 20aH are 3x6ish for 18 square inches. Five 4aH pouches per cell group times eight per half is fourty cells. Each pouch takes a fraction of the compression so you need to get a pounds per cell as a standard that would be true across all. I'll move this discussion to that thread, but it is a good time to compress, when you are splitting it and repacking to some extent. And now that I look at it, it actually looks like it is no longer square. Is it longer across the seperated plane than on the outside? COMPRESSION - STAT!

Edit: fixed spelling and grammer

 

[docnjoj]

I too had to go with Molex 9pins which I hate but our local HobbyTown just closed! And right before Christmas too! I will wrap the individual packs today with Gorilla tape but none of my pouches appear swollen. It is a fairly new battery with only 30 or so cycles so maybe I got lucky! We will see! I like the cutting in half of the connectorbut will probably go with JST when I order. I just hate to have to do this all over again. I'll run tests with the Molex.
otherDoc

 

[docnjoj]

It looks like I may have spoken too soon about bulging cells. It looks like one pack has one or more cells bulging at the end of the pack. The group reads 3.32 just like the rest of the groups of 5 cells, but it could be trouble. Stay tuned. I wrapped that pack with the Gorilla tape pulled tight but probably "the gas is in the bag" for those cells.
otherDoc

 

[docnjoj]

Well the deed is done! It is balancing and I'm gunna leave it overnight to do so. Cell groups rang from about 3.6x to 3.7x and the charger periodically comes on. This battery hadn't been used since about May so it needs to get on the trike and run to see range. I could run it thru my toaster for load but I finally got a set of panniers coming and I believe thay can take 10 lbs per side so it will be easiier and more fun than making toast! Stay tuned for a range report. I hope it doesn't quit too far from home! There are some bulged cells so I hope the Gorilla wrap helped.
View attachment 100_4120.JPG




otherDoc

 

[docnjoj]

Well initial tests show Fatpacks 1 Ping 0! The first mile went fine (1/2 down 1/2 up) but the second started a series of BMS cutouts on the Ping. At first I thought it was "bad cells" but luckily I still had the Fatpacks mounted and made it up the hill without coughing up a lung! On closer examination I found a poor connection between the 2 24 volt pings.(I wonder who made that) he says as an aside So time for repairs snd tomorrow will attempt again with the fatpacks powering the HobbyKing meter to retain peak values. It could still be bad cells but there is some hope. A couple of points:
1. The Ping power was stronger at first but not by much. I will repair the Anderson and try again tomorrow.
2, Having the 20 lbs of Ping on the tail really bothers the handling at speed even low in the panniers. I got tail wag at 22 mph downhill and really had to slow down! Mid mount batteries are better!
3. Fatpacks may be the way to go!
otherDoc

Oh yeah! Apicture of the panniers where the Ping lives. Say that fast 3 times!

 

[docnjoj]

OK so it's a horrible day in and out. I got a code ind my node (a common cold) and it is raining and in the 40s out. Yuk! So I remembers Ypedal and his light bulb resistance set up and I gets dangerous. I know any resistance is a good one when you need it so I finds an old electric griddle and cuts the wire and connects it to my battery and meter and lo and behold I got 5 amps flowing! Yahoo I can test! If I can get 3 hours out of the battery before the BMS trips I will be a happy camper. I started at 1:15 PM so stay tuned.
View attachment 100_4124.JPG

otherDoc (the sniffly one)

 

[docnjoj]

Oops! It is now about 1:45 and the BMS tripped! Damn! I was just setting up a little servo connector to a 12 volt source to keep the values on the meter but it is as I feared. Dead cells. At least I can narrow it down to which block of cells it is that fails first and then order cells from Ping. At least I can troubleshoot in sections. Great!(sarcasm)
otherDoc

 

[docnjoj]

Hey battery BMS experts! I think this was asked before but can I remove blocks of cells in group of 5 (4 ah for each group@ 3.7 volts) and jumper off the sections on the BMS to make say a 40 volt volt 20 ah battery. Or do I need to start over with a new BMS. Seems like it ought to be able to disable resistors and bypass groups. I dunno?
otherDoc

 

[docnjoj]

After taking the tape off the top and using my 5 amp "resistor" I find one group of cells at 2.7xx under load and all the rest at 3.2xx. Not surprisingly that group has a bulged cell. So instead of try in to chop up the battery further I guess I will order some V2.0 cells (4 amp hr) x 5 per group and try to replace the bad one(s). I'll tell you that for the price of 5 cells plus shipping plus needing a single cell charger I could almost buy 2 more fatpacks. Decisions, decisions.
otherDoc

 

[docnjoj]

And now, the results of that operation. 5 consecutive ups and downs on my 1/2 mile 4% grade with the downhills against the brakes.
Vmin 35
Amax 40
Watts max 1400
Temp 48F
The total package seemed slower than my 4 parallel fatpacks, but there were no BMS cutouts.
Total weight of the trike and me about 350lbs
Used about 3 Ah total out of 16 availible (maybe less if the 5 amp d/c tests were conservative, which they probably were considering the numbers here)
20 Ah 36 volt rebuilt Ping about 15 lbs and the new Signalab BMS worked flawlessly.
Pictures to follow but I am a bit underwhelmed with the power (or lack thereof)
Any and all comments welcome but it seems that Fatpacks may rule even at the new high prices.
otherDoc

 

[monster]

damn those cells are soldered in well! i just spent 2 hours trying to unsolder cells from my ping battery without cutting the tabs. its possible but requires some skills. im just swapping some old cells out.

i used two soldering irons a solder sucker and cutters. two irons are needed to melt the solder. suck as much as you can up and then cut the edges of the circuit board by the slits to release the tabs. the battery tabs can be soldered to afterwards so you don't really need more solder boards. the battery tabs are really weak where they enter the cell and the top tab is coverd in solder so it wont bend. its best only to bend the tabs when the top tab solder is hot and melted or the tab will snap where it enters the pouch. i kill 2 cells this way so far. its a really time consuming, stinky job to do.

 

[docnjoj]

Yeah it is, Monster. I would not do it again and I just had to cut end cell groups off (mostly). But the 36 volt Ping and new BMS work fine in tandem with the 16 ah 18volt fatpacks. It has been going for about 2-3 weeks with no problem, no diodes and just an occasional (1x) balance through the BMS. The whole system charges very nicely, albeit slowly, with a 65 volt 2 amp Ping charger that I modified. All is good for the moment
otherDoc.

 

[The Mighty Volt]

What sort of cells are in that? They look like prismatic pouches! I heard this battery barely weighs 8kg.

 

[docnjoj]

It was originally a 20 ah 48 volt Ping that I splt and had to remove several bad 5 cell sets. This eventually ended up as a split 36 volt 20 ah pouch battery. All cells balance well and it seems to play well with the 18 volt Fatpacks.
otherDoc