currie electrodrive help

[aljsk8]

hi

i have taken my currie electrodrive box to bits to try a new battery system

well the results were poor so ive decided to put the old sla box back together ive got it all back together
but when i first took it appart i cut the wires off to the charging socket - and now i dont know how to rire it back up

its an xlr socket and i can still see the solder blobs on 2 of the pins - but how do i know which is positive and which is negitive

also at the other end can i just solder the wires from the xlr to the terminals of the battery(s) i know it wasnt like that before as i thing negitive went to battery but positive went through the fuse

all in all im confused any wireing help would be great - or even a way i can suss it out for myself

i got the bike running batterys were full but it definatly lacks the power and speed it had origionally before all the messing around
cant understand whats going on

thanks

Alex

 

[fechter]

I don't have one to compare against, but if you have a voltmeter, you should be able to measure the voltage on the pins and wires. The critical thing is to get the polarity correct. If you attach it backwards, bad things could happen.

Most 3 pin XLR chargers I've seen use pin 1 for positive and pin 3 for negative, pin 2 not connected. If you look closely at the connector you should see pin numbers in the plastic.

You can connect the charger wires directly to the battery. It is better to have a fuse in line.

 

[dnmun]

can you tell us what you did? is it possible you could still do something to resolve why the original upgrade did not work?

sometimes you can just look closely at the cut ends of the wire and match the 2 ends together just from the way the wire or solder blob is severed.

if you don't already have one, get a voltmeter, it will eliminate your anxiety about this stuff in the future, and then you can check continuity, even from the PCB printed circuit board to the end of the wire where you want to reattach it to the plug on the battery case.

low res, close up pictures help.

 

[64ragtop]

Plug your charger into the XLR socket and use the voltmeter to determine which is positive. There are usually numbers (tiny numbers) in the plastic of the XLR, and I have only seen pin one used for positive - but I haven't seen everything!!! Check and double check, because hooking the charger up backwards to the battery pack will make NOBODY happy!

ATB

BC

 

[aljsk8]

thanks for all the help guys

1 question what exactly do i need to do with my DDM (voltmeter) to figure the polarity out

a nice idiots guide would help

thanks

Alex

 

[dnmun]

good to ask first. never try to use your resistance measurements while the parts are electrically active. don't leave the probes stuck into a circuit while you twist through the dial to get to the voltage range.

otherwise, the voltmeter goes poof, a little bit of smoke comes out and the dial sometimes glazes over.

you use the voltmeter part by setting the dial to the range, then apply the probes to the part to check voltage. to measure resistance, first set the range, then hold the probes tightly together to short them out. this should be your 'zero' ohm reading. you will see that the dial is not on zero, so you adjust the little thumb dial on the side so that the dial points to zero. this is called calibrating the scale. then apply the probe to the part needing to be measured and read the ohm value off the display. to measure current, always use a higher scale than you expect the current that you measure to be. you will see that there is a separate place to plug in the red lead if the current is over the low range available on the dial. if in doubt, always use the 10A range first, then once you know the current will be in range for the normal plug, then swap the red lead back over to the standard position and use the lower ranges.

and always remember that the probe is electrically 'hot' itself when you are probing a circuit, and touching the probe while measuring a high voltage will cause some harm, and possibly death if it is very high voltage. 240V will not always kill you, but it is very painful if you receive a sufficient current to burn yourself. always be safe, just like riding in traffic, you can control your own risk by just thinking of all the places you can accidentally touch an active wire, it will happen eventually, so be careful. technicians who worked for me always followed procedures for discharging large high voltage sections before entering the cabinet, i mean high rf voltage. even then, they would always short out sections manually with a screwdriver to be double safe, and eventually someone did blow up a screwdriver and it saved his life.

 

[64ragtop]

thanks for all the help guys

1 question what exactly do i need to do with my DDM (voltmeter) to figure the polarity out

a nice idiots guide would help

thanks

Alex

What dnmun said, but let me start from jump. (beginners are not idiots, just uninformed)

First, a couple of opening remarks. Your digital voltmeter might have even come with a manual! (manuals are handy - even handier if read and followed) but often not supplied with ultra cheap meters - no shame in buying cheap for this use!

In any case, your meter should have a dial to select types of measurements and the ranges. Most likely will have three jacks to plug the test leads into, and two test leads - usually red and black. the test lead jacks will probably be labeled something like "Common" (or "Com"), which is where the BLACK lead plugs in, "10 amps"(which we will ignore for the beginner lesson) and "V-mA-and the Omega sign (sort of a horseshoe, with the open end down) which is where you plug in the RED test lead.

The meter will probably have a rotary dial which may or may not have an "OFF" position. If no "OFF" position on the dial, then it should have a switch. Turn the meter on and see what happens to the display. If the display is blank, you probably need a battery or to plug a supplied battery in, if it is in the battery compartment. Now, let's be sure the test leads are plugged in correctly. Rotate the dial to one of the resistance scales (indicated by that omega horseshoe symbol) use the 2K or 20K position. Touch the tips of the test leads together and hold them. The digital readout should steady at "0.00". if it doesn't move from whatever the rest reading is, one or both test leads are not plugged in completely.

OK, if you have the leads plugged in and the meter is on and battery supplying power, and your battery charger plugged in and lit up, STOP!!!! FIRST, rotate the meter's dial to the 200 volt DC position. (the DC voltage ranges should be identified by a solid line above a dashed line) If you touch the test leads to a voltage source with the dial set to an ohms scale you will probably kill the meter.

OK???

NOW let's check that polarity. Plug the XLR connector into the charger jack and look at the inside of the jack. If you can see numbers in the plastic part of the inside of the charger jack, place the tip of the red test lead on terminal one and the black one on terminal two. You should see a voltage reading matching your charger voltage - probably 25 to 28 volts for a 24 volt battery pack, 37 to 40 for a 36 volt pack. If no voltage reading, try moving the black probe to terminal #3. If you can't see numbers on the inside of the charger port, just pick any two terminals and hold both probes on them. You may or may not see any reading, or maybe a reading as above with a minus sign in front of it. Keep trying different pairs of terminals til you get a voltage reading as above without a minus sign in front. When you have that, the red probe is on the positive power supply terminal and the black probe is on the negative terminal.

From that point, you should run a red wire with the original fuse holder in it to the positive terminal of the battery pack.

I hope that helps!

ATB

BC

 

[aljsk8]

perfect

i actually figured it out for myself last night and ive just logged on now and
got the same answer as what i did

i tested a 1.5v battery first to see what happened with the minus sign

when i was confident i did the same with the charger

ive used the digital meter before so i understand the dial and i know a little about ohms law
so i wasnt completly in the dark

but this info you have provided is outstanding for a beginer like me

so a big THANK YOU

terminal 1 was positive and 3 was negitive
wired it up and its all working

just to let you know what all this was for....

origionally i had the standard currie system - 24v 2 sla batteries 15ah each
it went 19mph on the flat and i was very happy

then i lost my job and didnt need it as i got a new job a lot closer to home (blessing in disguise)
but i thought id change to vapextech 12v 3.7ah nimh packs for the 1.5mile commute

so i rewired with 2 nimh packs - 2x 12v 3.7ah
but it lasted about 400 meters only went about 12mph then ran out

so ive now put it all back to how it was origionally fully charged it
and it only does about 15/16mph on flat and dosnt have the torqe it used too

i really dont understand whats happened

the only other thing i did as dismantel the whole system clean it all and regrease it and put it all together
now its very very quietits still not bad

all very strange

anyway it works - thanks to you guys!

 

[dnmun]

if you ran the 2 nimh in parallel, the 12V would be so low that the current draw could have damaged the motor. i assume it is a brushed motor, so the brushes could have cooked, or the wiring could be damaged, less likely. and the batteries were so small that maybe they were not capable of delivering the voltage under load in series, with similar consequences.

your SLA could just be old and tired, or the charging is not sufficient to recharge the battery. the chinese replacement motors on ebay are super cheap, and maybe you upgrade eventually to 36V, with new nicads, boost performance. BOL, dm

 

[aljsk8]

nimh were in series - 24v


yes it is a brushed motor
motor still works fine - just a little slower

sla were fully charged before i stopped using it for a few months
and the system worked well then (19mph)

so then after the swap and then back again it now goes a little slower (3mph)

wireing is all fine everything works normally - controller etc

???

 

[64ragtop]

I was a little concerned that I got a little TOO basic with my DVM instructions. Glad ya got it figured out! I'm wondering if these were the 12 volt packs you used:

10vp3700SC-H-T1

12v RX Power Pack Rechargeable Batteries 3700 mAh Ni-HM

Huge capacity and power from this power pack, suitable for many radio control applications.
Band new, high quality Vapextech cells, fitted with Tamiya 2-pin connector on a high current flexible lead.

They're the only 3.7 Amp Hour packs i found on the British Vapextech site. Their blurb would certainly lead one to believe that they could meet your power needs for a short distance (3.7 is only 25% of 15 AH). 400 meters at 12 mph seems AWFULLY short, though!

I'm wondering about a voltage sag perhaps damaging your motor brushes or brush holders such that the efficiency of the brush/commutator junction was altered. I've not been into any of my Currie motors (yet) but I think I read somewhere about plastic brush holders melting and allowing the brushes to rotate in the direction of the commutator's rotation and altering the timing of the motor or the contact of the brush with the commutator. I think that could produce your lack of power even though the motor sounds fine.

I would swear I've seen Currie replacement brush assemblies, but can't seem to find them just now. Maybe someone else here has a source.

ATB

BC

 

[fechter]

I hope you didn't get any grease/oil on the commutator. I think the motor is sealed so this should be pretty hard.

Other than that, look for a loose wire connector somewhere. Sometimes the prongs get bent out and lose their tension in the plugs. This can cause a high resistance and loss of power. The connector will get really hot too. All connections should be very tight and not have any 'wiggle'.

 

[aljsk8]

64ragtop - that is the battery - like you say it should have worked

the motor is sealed - so nothing could get inside

all wires are fine

i can hear the motor tops out at about 19/20mph when i pedal
and again it used to top out about 21/22mph

it has actually got a little better in the last few days
maybe doing 17mph on flat so im just gonna leave it alone

once again thanks for all the advice and help

Alex

 

[fechter]

Forgot to mention two other common problems:

Check your tire pressure. Pump them up to the max.
Check your brakes and make sure they are not dragging.

 

[aljsk8]

cheers