Deecanios first build the "DC1"

[Jozzer]

^^ what Gaston said^^
You should see the watts reading take a dive when the green light comes on the charger, hopefully it will still read some 15-50 watts, indicating that it is charging very slowly. If this is the case, let us know the reading, and we'll work out how long you'll have to wait before its recovered!

 

[deecanio]

Hi Guys,

well i went with the db inline so we could see what was going on and the batt started to charge at a steady 120w?
starting voltage on the batt was 38.1v which rose to 39.3v within five mins of being on charge (seemed quick).
the green light came on after 50mins and initially db was telling me it had put in 2.25ah (i had used 2.35 before lvc last time out) and 42.8v - alas the watts reading had dropped off to complete zero and once i unplugged the charger the batt voltage dropped to 39.3v then once i hooked the batt up to db the right way it read 39.1
mmmmmmmm.
i was going to take it for a ride but im fairly sure it will give me 2.235 ah then die, bah.
im charging the other batt just to top up so i'll see if that comes in the same again or improves,ill post up later once its charged.
maybe i should ride the dud and give it another couple of charges see if it improves with use?? - what do you guys think??

cheers


D

 

[fechter]

Can you measure the individual cell voltages?

You might be able to get a single cell charger and cycle each cell separately to try and get it back into balance.

 

[Jozzer]

Aye Deec, at this point you need to get into the packs and see whats happening. (sealed metal box Fech)

 

[deecanio]

Hi Guys,

second batt came up to 40.7 (40.8 last charge) so that looks ok by comparison
dammit i guess it will need to be opened up then (sweats at the thought).
My biggest concern is that once my packs are opened that will never be the same dimensions again and they fit in their frames to the millimeter, snug i tells ya
dammit. the metal box is thin and difficult i'd guess, knoxie said it was a bastard to crack it open and then repair.im not sure what to do now

cheers


D

 

[Ypedal]

I"d try to contact Knox and find out what's inside and in what location.

Open it carefully and you will be able to re-seal it like a can.

EXTREEM CARE needs to be taken not to nick a cell or wire inside while doing this, or the BMS so knowing what's inside and how it's put together is important here.

Me.. i'd use a dremel with cut-off disks and work slowly ( mask, gloves, full arm lenght shirt, if possible do this outside )

The alternative is that the packs stay on your desk gathering dust..

Considering you are not comfortable doing this, likely best to send it to someone with experience.

 

[deecanio]

ok thanks Y,Fech,jozz

i'll try and get in touch with paul, or wait till he shows in the new year, he's bound to cast an eye at some point.
jozzer we'll find out from paul whats where in the packs (i know he has opened and uprated the bms on two of these) and see what he reckons - the problem with the point 1 packs in series was the bms rating of 55v so i'm wondering whether its worth cracking both to uprate the bms at the same time? then i could use an uprated xlyte and run 72vx35a (walk/run etc).
1 thing i dont understand is how the imbalance occured (although i guess we are guessing until we open them) hopefully they wont do it again whilst in good use
i certainly dont have the know how to open these, this was one of the main reasons for buying the modular packs in the first place, maybe not the best cells in the world but just whack them on and they perform well when they perform
oh well one more hitch to deal with before i get this bike cracked at 72v - thanks for all the help guys, lets see what knoxie says and go from there, if theres anything else i can try let me know.


cheers


D

 

[deecanio]

Hi All,

i am looking to sell my point 1 lipo's, please see the for sale threads.


Cheers


D

 

[Ypedal]

quittin on them Poin1's are ya ?

Well.. can't say i blame you,

what's the plan for DC1.2 ?

 

[deecanio]

Hi Y,

i know you feel my lithium pain
i have few options at the moment, sell the batts as is,or let jozzer have a crack at repair.
the point 1's need uprated bms and repackaging so we are going to try the upgrade on the low charge batt and see how it goes.
i'll leave the good batt up for sale to see what ppl will give me for it if anyones interested as it is a corking battery when run at 36v,but you know that thats not enough for me :lol:
if jozzer gets the low batt fixed and repacked we'll do the good one too as knoxie has two of these uprated bms repackaged point 1's and they are fine.

so fingers crossed, if the upgrade doesn't work out i will buy some lipo from Gary, when i can afford it

cheers mate,


D

 

[GGoodrum]

Based on the behaviour exhibited, my guess is that one, or more, cells in this pack have been "stressed", and have lost about 10% of their capacity. More importantly, the "C" rating has also been reduced to the point that the voltage is sagging badly under moderate loads. The is tripping the LVC circuit in the BMS.

Another point is that if you have two BMS units, one in each pack, the 55V limit is not a problem. Since the packs are in series, the limit is really 110V In any case, it sounds to me like at least the LVC portion of the BMS is working fine, as it is pulling the plug, so-to-speak, before anymore damage can be done. I'm guessing if it does have some sort of voltage clamp/regulator on each cell, it is also working properly. the fact is if you have stressed cells, the voltage will drop about 5% within minutes of eing off the charger.

I'm pretty certain the cells in these are in the prismatic format, where each is enclosed in a sealed bag. With early version of RC LiPo cells using this format, there were a number of quality control issues where tiny bits of moisture got into the bags during the manufacturing process. This usually happened more often if the cells were made in the summer months, when the humidity was higher. What would happen is that at some point in the future, usually within six months, the moisture interaction in the cell would cause it to "puff", When this happens, the cell is pretty much dead.

I think what has happened here is simply that at least one cell was weaker than the rest, and the load just caused it to get damaged/stressed. If you end up keeping the packs, you'll need to do what has been suggested here, and let Steve, or somebody open this pack up in order check the health of the individual cells.

-- Gary

 

[deecanio]

Hi Gary/All,

thanks for the info Gary - my packs are winging their way to jozzer as he has far more knowledge than me and has kindly agreed to take a look and see what is going on inside.
Hopefully they will be ok and we do have some spare cells (pouches) if theres any damaged ones.
I have my eye on a new frame as we speak so that i can revert the DC1 back to original from for pedal cycling and move the wheels and electrics to the new frame (DC2).
if as we discussed the new pack is a frame traingle fit only and if we do manage to squeeze 20 cells giving me say 50-60 volts do i understand correctly what will happen to performance?
as things stand when i run 72v20a i have 1440w (have seen it hit 1800w) reasonably good torque and a top speed of 31.5mph.
if i were to run 60v but say 40a would this mean that my top speed would reduce to say 26mph but the extra amps would get me there a lot quicker? i have to be careful not to burn my puma so im looking to use around the 2kw mark?



Cheers


D

 

[GGoodrum]

Well, assuming that wind resistance isn't a factor that is limiting you to 31 mph now, I'd say yes, your top end will drop a bit, but with the higher current limit, you will actually be able to pull well over 2kW. When I was running a 20s4p a123 setup with a 40A controller, I'd routinely see 2400-2500W peaks. I've since had Bob mod this controller with the 4110 upgrade and he upped the current limit to about 85A, so now this little beast (it is on my 20" folding bike, with a 5303...) smokes the tire and hits 5500W peaks.

 

[deecanio]

Hi Gary,

yes i have seen the results in the vids, quite impressive!!
i have to be careful with the puma or i'll burn it - i figure if we go for a 60v pack (assuming it fits.will know the new frame size by weds hopefully) i will limit it initially to a "measly" 30a this will give me 1800w which is the recommended max according to knoxie's testing and that's good enough for me.
the big bonus of your pack is i can unleash muchos more amps as and when i have a motor that will take it (for me the x5 is out because of the weight, and there is nothing better than the puma pound for pound imo).
I'm totally happy with my motor as it pulls like a champ even at low voltage so 60v30a should be way plenty
i will probably get the 72v 35a puma controller from mark at some point and that hopefully will complete the bike, please god need more riding than waiting this year!!!!

cheers


D

 

[deecanio]

Hi All,

well made another push for a finished bike and bought a 2nd bike .
Have been looking for a kona stinky frame for a while now but they don't come up that often and i was waiting for a 19" frame,the frames have been going for between 170 (battered) - 350 so i decided to pick up a 2004 kona stinky bike complete for 450 instead.
It made sense to buy the whole bike as it has good quality components all round and i would have had to buy these individually anyway so that i could return the DC1 back to my plain old 26" mtb.
Anyway parts are swapped and was very easy as everything is the same size - now all i need is some power and i can try to get my game on
lots going on with the bike at the moment in terms of mechanical whilst i wait for the electrical side that jozzer is helping me out with, ill post up more once i get things done.

cheers


D

 

[deecanio]

Hi All,

Few more bits done now but i've been absolutely manic at work lately and i wont have time to put it all together for a test run for at least another 3 weeks, but hey 3 weeks after 14 months is easy as
Jozzer has pulled of a comprehensive overhaul of all my electrics and can't thank him (and knoxie) enough for the work they've done, batteries - sorted, both controllers - sorted, DC1 at 72v35a? - sorted - Mr jozzer,Mr knox take a bow!!! without these guys my bike would be long since sold/project terminated!!!

i'll have all my kit back at the end of this week so its all here ready to go - also bought a new bb and tools to swap cranks so just need to sort out new torque arms and db mount and im good to go!!!

Oh, also managed to get the rim done finally!!! the old one was ok but fugly as.
If theres any of you uk guys that need a wheel laced try mailing this guy - thesproat@yahoo.co.uk fantastic pricing and very quick turnaround, already know where my next puma is going for lacing !!!


hehe - listen to me, "next" puma damn you ebike bug !!

"just when i thought i got out, they pull me back in."


cheers all


D

 

[knoxie]

Hi Mate

Nice nice cant wait to see that machine finally turn a wheel proper!! we will deffo get and meet this year, I will have to knock something up myself to bring to the meeting!! thanks for the heads up on the wheel builder as well!!

Knoxie

 

[deecanio]

Hi mate,

no worries on the wheel builder - he's a sound bloke too so give him a shout if you need any lacing
Yes lets meet up in the spring mate, im really looking forward to actualy meeting you and joz this season and goodwood is looking likely for the first meet - If anyone else is interested for a UK meet drop me a line and i'll find out all the details.
Should be turning that wheel proper within the next three weeks or so, fingers crossed this bike should eat trails!!!

cheers mate, see you soon!!!





D

 

[Jozzer]

Good luck Deec...I hope it all comes together easy!

 

[Ypedal]

Awsome ! looking good D !

So what was the lowdown on the battery packs ? are you gettng the Point1 originals back in better shape/ballanced or different packs ?

 

[Jozzer]

I changed 2 cells out of the bad pack and repaired the BMS, fitted 100v fets to both boards(4310's), and added balancer leads and a thunderpower tp-210v balancer, and balanced them until they could be balanced no more! ...they now should be as good as they should have been when they were new (if you follow me) At least, I damn well hope so...or all was in vain!

 

[Ypedal]

8)

I will be using the same thunder power ballancer on my 20ah packs as well, the original bms is nothing but a headache...

Difficult to open the can ?

 

[Jozzer]

Not difficult, but very scary! (all live inside, and packed with wax that needs chipping out solowly and carefully!). Simply ran a file over the edges till it popped open

 

[deecanio]

Hey Y,

yes joz has done a cracking job on the packs - i will get some pics up soon as i can as i must be honest - i haven't even opened the box yet i'll take some pics as joz sent them then i'll wave my pretty wand and take some more once i put them back in the bike - need to change crank and headset first and mount the wheel.
I'm up to my ears at work like you wouldn't believe and i'm away at the weekend so i wont get to build the bike until next weekend but i do have a fully working electric kit at last thx to joz

Cheers

D

 

[Ypedal]

Hey D !!! what's up ? we need an update on this !