controller hookup - ignition wire

[RVD]

Hi Everyone,

I have the 9 FET 72V Infineon Brushless Controller (LYEN's Edition).

As you can see in the picture, this is a picture of where the battery should plug in. You see 2 anderson connectors for the +/- from the battery.

Between them you can see the thin red wire. This thin red wire is for the ignition. I don't have an ignition wire so the documentation (and Edward Lyen) says that I should just hook this up to the positive.

However, I have a few quick questions if I do that:

1) Will this cause a spark when I hook up the batteries to the controller? There is no on/off switch on the controller.

2) What is a good way to just connect this to the positive of the battery? Should I create a Y connector out of the battery so that 1 anderson goes out to the controller red and another anderson connects to this thin wire (convert this thin wire to anderson)?

Or should I strip this wire and solder it to the controller red wire together and crimp them together to form 1 anderson and then just plug in my battery to it?

Or is there another way that I should do this?

3) Is it easy enough to create an on/off switch and use the ignition wire for it? I think I would rather have an on/off switch for the controller if it's easy to build one using this red ignition wire.

For example, maybe hook up the ignition wire to a switch and also hook the switch up to the battery using a Y cable (one battery out to ignition + power on controller) and use the switch to turn on/off the controller?

 

[dnmun]

yep, put a switch on that line and you can turn off the controller circuit current when you shut down. the spark is from charging up the big input caps on the large red wires which you can leave plugged in all the time since they will not drain the battery down when connected, but the small red wire carrying the circuit current will drain the battery unless switched off.

 

[neptronix]

Yeah; pair it with the positive wire.

You will always get a spark. That's what precharge resistors are for. At 36v, not a huge deal. At 72v and above.. free arc welder!!

 

[Philistine]

yep, put a switch on that line and you can turn off the controller circuit current when you shut down.

Correct me if I am wrong, but my understanding was that if you leave the large positive/red connected, and you disconnect the thin/ignition wire, you will still be putting a slight drain on the battery. I am just trying to make it clear, that if you simply put a switch on the thin ignition wire, and left the bike plugged in like that (with the ignition wire switch off), you would still drain your battery. I understand that by turning off the ignition switch you will "disable" the bike, but my understanding is that it still will be draining the battery very slightly. Otherwise it would be great because you could just use a low amp switch on the ignition wire, but if you truly want to isolate the battery, you have to have a high amp switch on the main negative. That was my understanding, and I just wanted to be clear on that one.

 

[Alan B]

I measured approx 2% per day drain on my Lyen 12 FET at 75V when connected to the power lines and the controller's "on" wire disconnected. This on a 10 amp hour pack.

The "on" wire is good to put through a "kill" switch. It turns the controller logic off.

 

[itchynackers]

I run that thin red "ignition" wire all the way to the handlebars and to an anderson connector, then another anderson joined next to it and back to the main positive. So now you have two open ended andersons at the bars. All you do then is create a jumpered anderson to anderson "key" that fits into the open ended ones. You now have an easy emergency pull key near the handlebars. Ah...I'll just take a picture...

 

[skeetab5780]

that a pretty good key too...unless ur a electronics hobby nerd like most of us here. normal folk wouldnt figure that out.

 

[dnmun]

you can leave the large red wire connected all the time if you put a switch on the small red wire that carries the circuit current.

the voltage does not leak out of the large red wires because they are turned off by the mosfets for the phases. if there is no voltage flowing in the controller circuit that controls those mosfets, they remain turned off and the wires are essentially disconnected then. so you don't have to plug and unplug the battery from the controller, just shut off the switch. everybody does that i think.

 

[Alan B]

you can leave the large red wire connected all the time if you put a switch on the small red wire that carries the circuit current.

the voltage does not leak out of the large red wires because they are turned off by the mosfets for the phases. if there is no voltage flowing in the controller circuit that controls those mosfets, they remain turned off and the wires are essentially disconnected then. so you don't have to plug and unplug the battery from the controller, just shut off the switch. everybody does that i think.

This is the condition that drained about 2% per day in one test on my setup. Not bad for a day, but not good for a couple of weeks.

 

[auraslip]

IRRC the drain is 50ma - If you use you're bike everyday it's a real no brainer. I use a keyswitch on my bike.... no need for a precharge resistor on it because the caps are already charged.

 

[wojtek]

just a silly question - the key should be installed on the red wire between the battery and controller right?

Are you using 230v switches at around 15a/20a for more powerful ebikes?

Any good website selling them?

I found something here.. http://www.rapidonline.com/sku/Electrical-Power/Fuses-Circuit-Breakers/Circuit-Breakers/Rocker-Switch-Circuit-Breaker-M1-Series/400931/26-4323

but does it mean i should also use 8awg wires through?

 

[dnmun]

there are TWO red wires going to the controller. the circuit current that the controller uses to control the output mosfets goes in through the small red wire. the current that goes to the motor goes to the controller through the large red wire.

i repeat, you can wire up the large red wire to the controller permanently, and put the switch in the small red wire. it only has to handle the 60mA of controller circuit current so it can be very small.

 

[wojtek]

thanks!
there are TWO red wires going to the controller. => are you referring to the battery - controller wire? I never cut it before. All i did was to plug the battery to the controller wire with the anderson connector.. So what you are saying is that there are two separate wires inside the red cable [battery-controller or controller - motor]

I am referring to the sensorless lyen controller or the crystalyte controller.

sorry for basic question!

 

[RVD]

i think it depends on your controller. i'm not familiar with your controller although i'm sure other people here are very familiar with it.

on my controller, there were 2 red wires and 1 black to connect to the battery. on yours i don't know, if you only have 1 red and 1 black it's easy and not much to think about...just connect it to your battery pack and go.

 

[ABritInNY]

Yeah; pair it with the positive wire.

You will always get a spark. That's what precharge resistors are for. At 36v, not a huge deal. At 72v and above.. free arc welder!!

Lmfao, that JUST happened to me on my first install of a new 72v 30ah lifepo4 prismatic battery at 1st touch of positive, the crack/bang was so loud, that even though I was expecting it, I got quite a surprise (NO precharge resistor and no ignition switch) Then I remembered that in my 'dread,' I'd forgotton to serial both reds together, so now I've no power to my controller or CA, Sooooo, NOW I gotta gather up courage to disconnect the positive terminal and serial both thick and thin red wires together (I gather that's how Lyen's controllers work?) again knowing about the arc spark and bang and still probably jumping when it happens again lol... Higher Voltage scares the bejeeesus outa this Newbie.

 

[Ykick]

Yeah; pair it with the positive wire.

You will always get a spark. That's what precharge resistors are for. At 36v, not a huge deal. At 72v and above.. free arc welder!!

Lmfao, that JUST happened to me on my first install of a new 72v 30ah lifepo4 prismatic battery at 1st touch of positive, the crack/bang was so loud, that even though I was expecting it, I got quite a surprise (NO precharge resistor and no ignition switch) Then I remembered that in my 'dread,' I'd forgotton to serial both reds together, so now I've no power to my controller or CA, Sooooo, NOW I gotta gather up courage to disconnect the positive terminal and serial both thick and thin red wires together (I gather that's how Lyen's controllers work?) again knowing about the arc spark and bang and still probably jumping when it happens again lol... Higher Voltage scares the bejeeesus outa this Newbie.

Make sure to clean the connector contacts of any grease/oil, silicone, etc. That stuff tends to intensify precharge spark. Also, the plating or tinning used on Andersons seems to “fuel” a more intense spark.

Over time that shit wears down to the copper alloy and tends to spark less significantly. Especially, if kept clean of grease/oil/lubes using alcohol/solvent.

I’m not a precharge circuit user but my HOC (hot off charger) voltage is only about 67V. 72V systems around 80V HOC? That’s getting pretty intense I’m sure. Although the bottom line is that the “bark” much worse than the bite. Scares hell outta some folks and doesn’t bother others.

I get years and years of daily use from connectors so there’s really no significant longevity issue IME.

 

[ABritInNY]

you can leave the large red wire connected all the time if you put a switch on the small red wire that carries the circuit current.

the voltage does not leak out of the large red wires because they are turned off by the mosfets for the phases. if there is no voltage flowing in the controller circuit that controls those mosfets, they remain turned off and the wires are essentially disconnected then. so you don't have to plug and unplug the battery from the controller, just shut off the switch. everybody does that i think.

This is the condition that drained about 2% per day in one test on my setup. Not bad for a day, but not good for a couple of weeks.

AND It's doing the exact same thing to my 72v 30ah lifepo4 battery connected to my 4110 18fet 72v lyen controller!! after wiring an Spst key switch on the ignition wire, I left the battery cables wired up and turned off the controller by the key... 9 1/2 hours later on a switch on Test, my CA V3 tells me, I've 'lost' voltage from 84.5v to 82.7v :| ...That's not a "Minor drain" by any means...everything is 'stonecold' so what could be eating so much voltage?? I'm scared to check the drain in the morning, but need to test it all... Shame to "waste" discharge/charge cycles for nothing

 

[999zip999]

When not in use I unplug battery. No leak. ? I also use a precharge resistor a must 48v and above.

 

[RVD]

I also unplug whenever I'm not using the bike.

I also built a precharge resistor many years ago and it's still going strong.

Coincidentally, I just picked up 50 resistors today to make some more precharge resistors. I don't need 50 but it was only a few bucks and cost the same as buying only a few.

RVD.

 

[ABritInNY]

So is there any decent priced precharge resistors built into a Key switch (led resistor optional but would be nice,) would e.g something like this work, http://www.adafruit.com/products/482?gclid=CjwKEAiA3_axBRD5qKDc__XdqQ0SJAC6lecALnaKq3NtTX8wyCOI6lNO60le1fungnbwL2Ez5iEmRxoCEPTw_wcB and if dso, how best to wire the on-off batt disconnect?

 

[ABritInNY]

Ok it's getting a lil weird with this battery drain condition :? it simulates a parasitic drain rapidly - from 90v HOC (that is the 24s lifepo4 charger the factory sent with?) that drops rapidly to about 86v (which I blv is the BMS in control, shedding voltage?) then a faster drain, that is steady till about 81.5v and much slower discharge from then on, so that by the 3rd day it only drops 0.2v/day...what the 'bleep' is going on here guys? at the slow rate It'll likely take all winter to drain fully, but that's not the point, I'd love to figure this out already :| ...

 

[amberwolf]

On LiFePO4, near top of charge the voltage drop as it drains will appear quick...then it has a nearly flat voltage level thru most of the rest of it's draining, then suddenly drops off again once it's near-dead.

What you're seeing sounds perfectly normal for that kind of pack, under a small load, but you could open it up and monitor the individual cells if you like, to be sure there arent' any cell-level problems (balance issues, etc).

 

[ABritInNY]

On LiFePO4, near top of charge the voltage drop as it drains will appear quick...then it has a nearly flat voltage level thru most of the rest of it's draining, then suddenly drops off again once it's near-dead.

What you're seeing sounds perfectly normal for that kind of pack, under a small load, but you could open it up and monitor the individual cells if you like, to be sure there arent' any cell-level problems (balance issues, etc).

Thanks for the re-assurance Amberwolf, it's my 1'st lifep04 pack and it appears to be a unique kinda chemistry from what I'm seeing so far... @about 80v the discharge is so level it's freaky, but (combined with the BMS programming) seems to be in line with what I'm now reading... I know if I give in to re-opening the batt pack, I'll end up ripping the 60a-120a bms out (to keep more voltage/power and rely on CA3 protections for the pack, saving weight, space and complexity BUT losing pricey protection, so for now I'm holding off... On a side point... during initial testing, my CA rated my batts resitance and 0.35 ohms, I'm indoors testing in heated warmth, could that affect the values? or is it accurate on the CA3 factory calibration and taken from the voltage diff on my acceleration tests?
Also for some reason the Pack only rates near 1,800 wh instead of the over 2100 I was expecting with a 72v 30ah batt... Chinese factory specs are sooo misleading... Therefore if it's a rapid voltage drop at the bottom of the cycle too + I've diminished capacity overall, I'll have to err on the side of caution until I fully understand the packs limits and capabilities, I thought I read on the CA thread that the SOC display for the battery is suppossed to correct for that if Lifepo4 is set in parameters.

 

[ABritInNY]

IRRC the drain is 50ma - If you use you're bike everyday it's a real no brainer. I use a keyswitch on my bike.... no need for a precharge resistor on it because the caps are already charged.

fine, I understand that and me too (currently, excuse the pun) but what about when you need 2 unplug and update the controller programming?

 

[amberwolf]

I know if I give in to re-opening the batt pack, I'll end up ripping the 60a-120a bms out

I wouldn't do that. Then you're going to need to manually balance the pack whenever you charge it up, and you won't have anything to protect the cells from too deep a discharge, since as you get down to the bottom of the capacity of the pack the discharge curve drops off rapidly, and any cell that is a little lower than ohters could be overdischarged before any manual or CA voltage protection detects a problem and stops the motor system.

The other issue is if it's designed to protect against overcurrent, and you remove that protection, then either your usage of the motor system or a short in the wiring would be allowed to draw more than the cells may be meant to take. Again, any manual or CA protection is slower to react and might not prevent damage.


Dunno about the internal resistance stuff, or the SOC stuff in the CA.

Usable Wh of the pack depends on the HVC and LVC of the BMS; those may be set conservatively to prevent damage / early wear to the pack.

Or the cells may simply not be as good as you'd hope them to be, for whatever reason.

Either way, the BMS, if designed properly, will protect the cells from damage better / easier than you can do it manually, especially while you're riding, so I'd leave it on there unless you find a problem with it that's actually causing damage to the pack.