KMX Cobra

[Ypedal]

Time for an update !

lmao.. tommy.. hilarious.. but so true ! .. this weekend messing around in the garage, i kept going for short rips up the road, thru the construction yard.. back home.. work for a bit.. go for a ride.. got more ballzy as i put more seat time on it.

I had my first tip-over on sunday ! .. my driveway is 2 cars wide + , doing as tight a circle as i could i kept adding throttle and leaning until i reached a point with 1 wheel just off the ground for another turn then zoink.. i tipped.. being so low to the ground tho i just rolled over and back onto my feet ! ( yes.. wearing gloves !! but no helmet.. )

Aaany ways.. so this past week i've been real sick, wooping cough is going around here and everyone is sick it seems.. was my turn last week. so i'm all goofed up on cold meds.. stuffed up . ears ringing.. just kinda physically messed up but mentally ready to bike..

Anyone see the problem with this picutre ?

[Ypedal]

I disconnected both 24v 10ah packs to charge with 2 seperate soneil 5 amp chargers..

Once charged, i checked all cell voltages, 16 cells all at 3.457v , perfection ! ( No BMS, 2+years not ballancing, used at times, sitting for months .. )

so i grab a red and a black that are aimed at the Cycle Analyst and hook'em up., i hear a " pop " . that familiar crackle you get when the controller powers up ( charging capacitors ) .. then i look over and see another + and - pair..

Without registering wtf i was about to do, i just plug them in to complete the 48v junction between teh 2 packs.. but wait.. i heard the controller power up.... uhm... ** all this in about a 2 second cound ***... then i hear a WOOOSHHH... and a huge puff of white smoke come billowing out the side of the trike and fills the garage !!!..



snapping back to reality, i swipped thru the wires thru the smoke and luckily hooked the right wire to seperate the connection..

the anderson housing melted off and coated the connector..

[Ypedal]

Grabbed the pedals and yanked the trike out of the garage and let the air clear..

I was sure one or more cells were going to vent, i quickly grabbed the top pack and pulled it off and clear of the house..

Got the volt meter out and would you imagine.. 3.335v all cells.. and aprox 40 celcius cell temps.

in 10 minutes i had this thing apart.. Bonus for nuts and bolts packs.. they are large and bulky but easy to repair !!.. been wanting to change the stiff car audio cable for soft silicone turnigy 10 awg wire.. so made up a pair.. bolted back on .. re-charged the pack , took 5 minutes to top it off.. checking cell voltages all 3.45x at green light..

[Ypedal]

also, now.. this was noticed PRIOR to the battery incident.. .. fairly cold, like 2 celcius, when powered up it shows voltage, kph, ah, watts, as expected.. but short ride later i look down and this :

kmx47-ca.JPG (43.65 KiB) Viewed 288 times

The trike is still running fine, full power, so i pull over. disconnect and hook back up, the display comes back and i ride again.. a few seconds later i'm back to black boxes.

the CA is calculating Ah , it shows an increase when i cycle the power, is this the cold temps ? or something else going on ?.

i've run the originals, V1, 2, etc. small screen way up into the minus double digits temps and never had this problem. bigger screen different ?

[Doctorbass]

also, now.. this was noticed PRIOR to the battery incident.. .. fairly cold, like 2 celcius, when powered up it shows voltage, kph, ah, watts, as expected.. but short ride later i look down and this :

kmx47-ca.JPG

The trike is still running fine, full power, so i pull over. disconnect and hook back up, the display comes back and i ride again.. a few seconds later i'm back to black boxes.

the CA is calculating Ah , it shows an increase when i cycle the power, is this the cold temps ? or something else going on ?.

i've run the originals, V1, 2, etc. small screen way up into the minus double digits and never had this problem. bigger screen different ?

The only two times i got a display like that i was never able to repair it.. it was the chip inside that blew so i needed to send both to Justin

Doc

[Ypedal]

Doh. !

[sn0wchyld]

ha... happens to the best of us mate. Particularly when your playing with connections while your less than 100%. Ive done it too, shorting out a 20s pack. Luckily the bullet vaporised, all that happened is I ended up feeling like I'd just been starting at the sun for a moment or two. That and someone just jabbed me with 100cc's of adrenaline . Lucky you got away with nothing more than some fried connections and blown caps.

once you're back up and running... how bout some vids?

[Doctorbass]

Maybe time for upgrading to the new V3 cycle analyst

I contacted Justin to get one for my new Zero motorcycle

Doc

[Ypedal]

heh heh.. yeah.. when you screw up with Lipo you dont even get the connectors to clip in.. they vaporize instantly... lower C rate cells are not as volatile ( and these PSI cells are still capable ... compared to lower end 2C stuff )

[Tommy L]

Time for an update !

lmao.. tommy.. hilarious.. but so true !

Welcome to the 3 wheels of joy! \\m//

[Tommy L]

Maybe time for upgrading to the new V3 cycle analyst

I contacted Justin to get one for my new Zero motorcycle

Doc

DOC!!!! You have a new ZERO? I can't wait to see some posts..

[Tommy L]

I disconnected both 24v 10ah packs to charge with 2 seperate soneil 5 amp chargers..

Once charged, i checked all cell voltages, 16 cells all at 3.457v , perfection ! ( No BMS, 2+years not ballancing, used at times, sitting for months .. )

so i grab a red and a black that are aimed at the Cycle Analyst and hook'em up., i hear a " pop " . that familiar crackle you get when the controller powers up ( charging capacitors )

I use a 100watt light bulb as a pre-charge
Still a little pop/crackle, but way smaller!

Got that tip here on ES

So glad that no one or your project got damaged. \\m//

Tommy L sends....

[Ypedal]

Been taking the KMX out for rides almost every night, have had everyone i know try it ( at least 20 test pilots so far ) and gets big thumbs up from everyone..

Tonight the sky was grey but the urge to ride got me out again, this time my neighbor came along on his 100v 9C 100 amp bike ( damit.. i need more power.. emailing Lyen as soon as i post this to confirm a controller purchase.. 18 fet 4110 unit on it's way shortly. )

Went to the local park, was a school football game on, plenty of questions and looks ( must remember to bring business cards when i go out on this thing, at least i had the shirt ! ) .. it's a chair anywhere you go.. pure awsome..

the PSI cells are good to go.. no sign of damage from the dead short incident, and delivering 7ah with voltage holding strong. cool.

the CA has been working properly since the weather has warmed up, no more black blocks.. yet...

[Sacman]

So where are the videos of you screamin' around town?

[Tommy L]

So where are the videos of you screamin' around town?

Yes YPEDAL..... just where are those vids? lol

Uploading mine to YouTube as I write this.....

Tommy L sends...

[Ypedal]

heh heh.. was telling the neighbor last night we need to get video making.. not very impressive at only 48v, but at least we can make a before and after comparison !

Weather is going to suck pretty hard for next few days but hopefully on the weekend we get some clear skies.. got a reply from Lyen last night, controller will ship soon.

Must also order some lipo.. that's a today plan.

[bdc43]

Would have loved to join you and your neighbour on your test ride but I was stuck recharging my pack from a ride the night before (got home late so didn't have time to charge before heading to bed). Hopefully I can join you guys on the weekend (if the weather holds).

[Ypedal]

alrighty...

I just ordered 6 of these to get started with, first time ordering nano's. :
http://www.hobbyking.com/hobbyking/stor ... duct=20548

[Tommy L]

alrighty...

I just ordered 6 of these to get started with, first time ordering nano's. :
http://www.hobbyking.com/hobbyking/stor ... duct=20548

\\m//

[Ypedal]

UPS guy arrived this morning !!!!

[Ypedal]

All 6 cells , in all 6 packs are showing 3.810v to 3.820v on arrival !!!...

Topping them all off as i type this..

[Ypedal]

4 packs ballance charged, at 1C ( 4.5 amps ), and discharge at 100v from a portion of my lightbulbs at 5.25 amps, while the last 2 packs ballance charge.

I also received my Lyen 18 fet controller.. more on that shortly !

[Ypedal]

An honest 4ah ! ( From 4.5ah cells ) from cycle 1.

I dont like to deep discharge packs, but it's the only way to know what's in there and prevent an overdischarge on the road.. weakest cell dropped to 3.455v at the 4.0 mark all others at 3.5xx wich is just awsome.

[Ypedal]

pack remained cool ( room temp is 23c , comfortable vacation weather !! ) .. up to the 3ah mark, and slowly got warm to 4ah when i pulled the plug.. outside pack temps 36c

[Doctorbass]

pack remained cool ( room temp is 23c , comfortable vacation weather !! ) .. up to the 3ah mark, and slowly got warm to 4ah when i pulled the plug.. outside pack temps 36c

Great!!

I guess you feel really happy now

Just to let you know, the lithium cells dont like to be discharged too low because of the heat that they produce when at the end of discharge when their RI is increasing. But the nanotech are very low RI compare to other lipo cells so no worrie about low discharge to 3.00V. You will not reduce their cycle life by discharging them to 3.00V... it will only happen if you leave them too much time at low or high state of charge.. ex 3.00V or 4.20V



Doc