battery is throwing sparks from the charging cord

[vjpcat]

hi everyone - i'm new here and don't know a whole lot about ebikes, but i've got a serious problem with my set-up and don't know what to do or if the system is fried now or what.

here's a little background on my bike:

a friend gave me her bike which had an aotema front hub installed powered by three 12v batteries (i am unsure if they are in series or parallel or what kind of batteries they are - they are newer than the bike's motor system as my friend had replaced them in the last couple of years)- i believe she said she purchased it from evergreen. it is an older model that she purchased several years ago. she gave it to me in august last year. it was not completely working - the throttle lit up, but no power was going to the hub. i found a document online which had the troubleshooting procedure and all seemed ok, but the connectors to the hub broke off, so they might have been weak. i replaced the connectors (anderson? look like trailer connector) and got the bike working ok.

since then i had used it a few times and then decided to move the system to another bike, which i did successfully. i haven't really rode it more than just down the street and back while testing it and working on the bike. the last time i rode it, i noticed the battery warning light come on on the throttle, so i plugged it into the charger the same as i always have in the past, only this time i noticed there was no spark or pop when i connected it. i let it charge until the charger light turned green and went to unplug the battery from the charger. it seemed tight and like it did not want to come out, but i kept on pulling and was able to separate it, but there was a lot of sparks and possibly a flame for a moment. very scary. i just tried to move the plug connected to the battery with a wood handled rubber spatula and again, more sparks and a flame. it appears to be welding itself onto the metal bike rack which supports the battery.

i am afraid i t may have fried the whole system, but i am scared to touch anything now as the cable coming from the battery is still live. anybody have any thoughts or suggestions. i am at a complete loss. thanks much for your help!

jaime

RCA style female connector

you can see where it arced onto the bike rack and burned it

battery charger and male RCA style plug that connects to battery for charging

controller is attached to bike just below seat

battery bag on metal bike rack

 

[el_walto]

Obviously there is a connector problem. If you have two wires coming from the battery, cut one wire, put some tape over the end. Then cut the other wire and put some tape over the end. Do not cut both the wires at the same time, as you will short them together. Replace connectors with some decent ones.

Maybe you can provide some pictures for clarification.

 

[vjpcat]

thank you. i'm not sure i completely understand that - there is only one connector (an RCA style plug), and i think it does have two wires coming out of it, but i will post pix soon - i figured it would be helpful. also wondering if i posted this question in the most appropriate section of this board...

 

[el_walto]

Do you have a digital multimeter or voltmeter? You can measure the voltage of the battery, and charger by using one of these.

Is it sparking while plugging it into the bike?

 

[Gregory]

Sparking when connecting charger - can mean you need to turn the charger on first before connecting the battery. Normal.

Hard to disconnect - sounds like the connector heated up during charging which means a poor physical connection or under rated connector and melted itself. Replace the connector.

Sparks and flame on disconnect - no idea, something is broken and shorting. Measure voltages with a multimeter. Replace connector.

Welding to frame - your bike frame isn’t chassis grounded is it? Charger fitted to the bike?

 

[999zip999]

Sometimes the conntor twrist and the wires short. Or loose wires in the plug. Those plugs can be junk.

 

[vjpcat]

thanks for all your responses - i will read thru them in a bit. i just wanted to let you know that i've updated my original post with some pictures - hope they help. also, the batteries used here are SLA.

el_walto - yes, i do have a dmm, but i'm afraid to touch anything on the bike right now. it sparked again when i moved the wire coming from the battery, but i think it was just when it came in contact with the metal bike rack the battery sits on. do you think it is safe to remove the battery from the rack as long as i do not let the connector touch metal again? i will test the battery voltage and all the circuits when i am sure the battery will no longer throw sparks. and no, well i haven't tried since, but it never sparked when plugging in although it did make a pop sound everytime except this time.

gregory - no, as i just mentioned, it never sparked on connecting, but there was the lack of a pop sound when i connected it this time. i'm not sure what else to call this kind of plug if it is not RCA or phono style, but i have updated my original post with pix so you can see what it looks like. your comment on the difficulty disconnecting makes sense - perhaps the wires were loose and shorted out - the battery may have had such a low charge to start that it did not even pop, but once charged, if the wires were loose, then that would explain the sparks and shorting out. these connectors probably are crappy and did have tape on them, so they may have just been put together poorly. also, no, i do not think my bike is chassis grounded and no, the charger is not fitted to the bike.

999zip999 - after reading everyones comments here, i would not be surprised at all if the plugs are the problem.

so, now i have a couple of new questions:

is it possible that the batteries or controller may have been damaged when the wires shorted? i suppose my multimeter will tell me so...

and assuming all will be fine if i only have to just replace the connectors for the battery and charger, what type of connector would you recommend that i use?

thanks again for your input!
jaime

 

[dogman dan]

I had immediate problems with that piece of shit RCA plug on my first aotema kit years ago.

So yeah, you need to fix it. You haven't ruined anything yet I think, not even the charger.

Open up the bag, and disconnect the red positive wire and the black negative wire from the battery pack. Now you can work on the connector on the wiring harness.

My favorite plug replacement on those kits is an Anderson Power Pole. Get some, and being very careful not to mix up the wires, replace the plug to the charger.

I eventually needed to replace the battery to controller plug as well. The bullet connector got eventually damaged by plugging into the controller, that does make a spark every time. 15 amps contacts are fine for charger wire, and 45 amps contacts are perfect for the larger wire to the controller.

 

[The fingers]

I smoked one of those on the battery side of the Amped kit. My fault though, I tried to use it after it got smashed a bit. Kind of a PITBoaz to replace, but I did it. The charger end looks trickier.

 

[dnmun]

does it still charge through that plug? it shorted across the outside ring to the center on the frame so if you can avoid doing that again you should be able to use it since your charger is likely only about 2A.

 

[FeralDog]

I had immediate problems with that piece of shit RCA plug on my first aotema kit years ago.
So yeah, you need to fix it. You haven't ruined anything yet I think, not even the charger.
Open up the bag, and disconnect the red positive wire and the black negative wire from the battery pack. Now you can work on the connector on the wiring harness.
My favorite plug replacement on those kits is an Anderson Power Pole. Get some, and being very careful not to mix up the wires, replace the plug to the charger.
I eventually needed to replace the battery to controller plug as well. The bullet connector got eventually damaged by plugging into the controller, that does make a spark every time. 15 amps contacts are fine for charger wire, and 45 amps contacts are perfect for the larger wire to the controller.

^^^^ dogman is Exactly correct.
I have one of those old Three 12volt (wired in series 36v nominal 12aH) blue battery bags on my shelf.
Do as dogman says and un-zip the bag. Then disconnect (or cut) one Red POS Or Black NEG wire at time that leads out to that burnt connector. NEVER cut across two wires at the same time, or you could get some sparks because your cutting tool could act as a metal "bridge" to short the Positive to Negative
There are 2 major problems with that style SLA in that bag.
#1 Those RCA style connectors don't hold up to much wear, or weather, over time. They fail.
#2) The "wiring" used in the various battery connections is often cheaper "braided" copper wire. Those SLA bags got a bad reputation for the cheap braided wire working itself loose from connections AND the wire did not really carry the amp load well from the battery. Also, over time, the bag fabric can rub and grab the wires. (And some of those old 2 amp Chargers had e-bike suppliers "instructions" that directed you to "Connect (charger) To Battery First: Then Connect To A/C Outlet".)

You will likely benefit greatly from new solid copper wires Or better silicon braided wires (if yours doesn't already have them), and new connectors.

Do you have local "Hobby Shop" that has R/C (radio controlled) items for sale?
If so, they may have all the parts you need to make your battery pack safer.
Best of Luck to Ya , and Welcome to the Forum.

 

[999zip999]

Nice two dogs helping a cat. Use a multimeter before cutting wiresto see if there hot. Then you can untwrist that Rca connector. Plus where does this cat live ? Post please.
Plus check with M.M. then check again always.

 

[dogman dan]

That is odd, usually I chase a cat up a tree right away.

If I remember right, that female RCA plug has the + on the outer connector. Incredibly dumb design, since it's ready to ground on anything it may touch.

Yeah, check for the right polarity on both the charger and the battery when you change that plug. Then, after putting on the plug, check again. I fried a charger that way on that steep part of the ebike learning curve.

Get a proper plug too, I fried another charger by using a lamp cord AC plug "temporarily" Of course, I soon plugged the DC side into the wall. Then for a time I used molex plugs from radio shack. They kept malfunctioning. Only when I started to use Andersons did things finally last.

Powerwerks is the place to get them in the USA.

 

[100volts+]

Think of those sparks as training for when you vaporize a set of connectors into plasma and get partial or full on kff.

 

[vjpcat]

hi y'all -

ok, let me run thru your replies again - quickly tho.

dogman - i will follow your suggestions and i will get the anderson power poles. i have already replaced the controller connectors once before, as well as the motor ones which are the same - pigtail trailer hitch style - they definitely are not made to last. i had actually found a couple of those pigtail connectors on cut wires yesterday at my local salvage yard thinking i would use those to replace the RCAs, but i do see the andersons are most appropriate.

oh btw, forget my comment regarding the lack of the pop sound when i plugged in the charger - i realized i was thinking of the controller, but for some reason thought it was the charger that popped. anyway...

so, do you still get the pop with the anderson connectors for your controller? i read that i could install a high power switch or relay to eliminate the pop, but perhaps it's not necessary with the anderson?

dnmun - i have not tried to charge again since - that plug is obviously fried and with so many verifying how crappy it is, i am going to change out the connectors before hooking it up again.

feraldog - thx for the bag comments - i always thought the bag was crap too - had no idea about the wire issues with it. one thing i've noticed is the zippers are broken and it does not open/close easily at all. what can i replace that with?

i suppose a battery wire overhaul is next on my bike repair agenda. i think i have some solid copper wire, but what gauge should i use there? the SLAs kinda suck - they're so big and heavy. i (eventually) would love to use a lighter weight battery system, but that's (financially) a ways down the road for me, so i have to just tune-up the stuff i got for now.

back to your questions/comments -

yes, there actually is a real good rc shop nearby - i've been in there before looking for something else, but i just checked their site and they don't carry anderson power poles - suppose i'll have to order that stuff online? i'll stop by that rc place anyway - they super nice and it's just down the street a ways.

999zip999 - ha! great observation. funny.

i will definitely use my multimeter first, but wouldn't i end up cutting (and stripping) the wires anyway or is there benefit to twisting the RCA off before replacing the connector? oh maybe you're thinking i could reuse the RCA? or maybe i can't test with MM unless exposed/stripped? i don't know - excuse me - i'm tired now. i'll re-read this after some sleep and it'll probably make more sense.

this cat's in northern california - sonoma county these days


dogman - i'm not in the tree yet.

yea, i was wondering about that with RCAs - you're right, stupid design and why would anyone every use that as a power connector?!

thx for the polarity check reminders - i'm usually fairly conscious of that sorta thing, but i am fairly new to the DIY electrical stuff. scary thing is, i tend to take on stuff with a trial/error approach. best not do it that way with this stuff, huh. guess i'm lucky tho, that i can learn from y'alls' mistakes :wink:

so, is powerwerx the only place to get them or is there a chance i could find them locally? i'll look into that some too.

100volts+ - kff?

goodnight y'all - gotta sleep. will check back tomorrow.

thanks again for all your help - i really do appreciate your expertise and experience. even you dogs.

 

[dogman dan]

Yes, you will still get the spark with the controller connection. But, if you just had it connected, then the caps will still be full inside the controller, and then you will not get the spark. The spark is the current rushing into the capacitors when they are empty when you connect.

I like the andersons, because their design is intended to take the spark a the tip when connecting, then slide in to make the final contact on clean un burned metal. I have some andersons on controllers that have lasted 5 years taking that spark, and are still just fine. Others add a circuit to reduce the spark, which can be very good with other types of connectors.

Make sure you don't mix up wires. BEWARE, WE has been known to use the same bullet connector on both sides. This means on one side of the plug red is +, but on the other side red is -. You likely noticed this already.

 

[100volts+]

100volts+ - kff?

KFF = Kentucky Fried Fingers

 

[The fingers]

=ouch!

 

[999zip999]

to open up the RCA connector you untwist to open it up, this will show you if the wires inside are shorted against the the metal connector themselves or some part of the connector. This was just to see if the wires inside the RCA connector were shorted out and causing the problem. I believe your local RC shop would probably have a connector don't use solid copper wires there's much better 10 gauge 12 gauge wires that you can use for your thing.

 

[FeralDog]

feraldog - thx for the bag comments - i always thought the bag was crap too - had no idea about the wire issues with it. one thing i've noticed is the zippers are broken and it does not open/close easily at all. what can i replace that with?
i suppose a battery wire overhaul is next on my bike repair agenda. i think i have some solid copper wire, but what gauge should i use there? the SLAs kinda suck - they're so big and heavy. i (eventually) would love to use a lighter weight battery system, but that's (financially) a ways down the road for me, so i have to just tune-up the stuff i got for now.

The major issue with Three SLA 12v batteries is the weight of approximately 26 pounds total. Their own plastic casing is A-Ok to protect them but the problem comes in handling them , and rough riding with them. Those Three batts need to be securely bound together (using strong tape ?, or a cable ties ?, or ?....) and they definitely need a very, very sturdy HANDLE for you to lift them (or they will tumble upon your toes).
That "bag" was an older e-bike kit makers solution to those issues of holding the three SLA together and (sort of) providing a handle in a "decorative" package, while trying to keep the bag on a rear bike rack with Velcro straps.
Because of the cheap Chinese wire available back then, combined with the funky "connectors" , many e-bike kit providers would go ape-sh*t and threaten to Void A Warranty if the customer used their own connectors. Cheap Chinese braided wires didn't last well over time in those bags with funky connectors , SO some e-kit sellers found that solid wires were much less troublesome in that package.

Since you may abandon the "bag" you are free to use your own choice of wire & connectors, make your own securely held together batteries, and make your own handle. A simple decorative "tackle box" can disguise the bound batteries , but the "tackle box" lid handle won't carry 26 pounds of lead very well. Customizing your own battery case is not too hard. Lots of examples for simple cases here on ES.

On Andersons Powerpoles, they will do the job and you should look into what wire size (and type) you will need if you choose to use them. Andersons will give you a bridge to the future if you choose another "better" battery chemistry later on. I started out with mostly 12 gauge quality Zip Wire and 30 amp Andersons, then I got some 10g wire and some 45 amp Andersons ------> see the specs before you buy http://www.powerwerx.com/anderson-powerpoles/powerpole-sets/ ..... http://www.powerwerx.com/wire-cable/

Finally, on suspect "connections" and "switches". I hate handling a funky junk hot switch or connector. I prefer to disconnect , or neuter the damn thing first ( I worked with high voltage applications and had some wild experiences!) That RCA connection is crap for your e-bike. Cut it and trash it.

Some pics of my old SLA "bag" connections.

 

[dnmun]

like i said, if you can plug it in now and it will charge there is no reason to do something different since it is only a 2A charger and the RCA plug will handle it. you just have to be more careful about letting it short out on the frame.

 

[vjpcat]

ok, i checked the batteries and they're good - 38.99v. the wires inside the bag looked ok, but should probably be cut and reconnected with more heat shrink as i did see some copper.

oh yea, my charger is not even 2 amp. it is only 1 amp, which i guess just means it charges slower? or maybe because it's old equipment?

i do want to get rid of the shitty RCAs - i don't ever want to see flames coming from the battery again, so i placed my order for 10 anderson power pole sets with the 30 amp contacts. i went with 30 amp because i read the 15 amp contacts don't fit solidly in the housing and i can just double over my charger/battery wires (18 and 16) to fit well and i can use the 30 amp when i upgrade my controller connector.

i will twist open the RCA out of curiosity, but i still have to disconnect from the batteries.

my package wont be here for a week tho, so i'll let y'all know how it goes then. thanks a million again y'all!

 

[dogman dan]

You can use the 30 amps size with the thin charger wire. I just fold the wire over the insulation, then crimp the wire and the insulation. Or, if you solder them, just fold over the wire several times.

 

[vjpcat]

yea thx dogman. i'd like to solder it, but i'm new to soldering too and not so confident i could make a clean enough joint, so i'm going to crimp. i was going to say i hadn't read anything yet that recommended one way over the other, until just now when my friend showed me a how to article on crimping anderson power poles, by, guess who, which i noticed at the very end after reading through the whole process.

funny thing is i had just finished telling my friend about the dogs and cats on E-S and there was the dogman 8)

 

[999zip999]

I crimp and solder. Start with a hot iron. Put the tinned iron on the peice then put the rosin core solder on other side and let flow in. Done. It's easier the cleaner it is.