48V 1000W Conhis Motor Upgrade

[sheikhuu]

HI everyone.

I bought a 48V 1000W conversion kit off ebay about a year ago and now i'm thinking of an upgrade, but don't know if that's feasable. The thing is that, currently, a 26Inch rim is laced on to the hub motor and i can acheive 52km/hr with that configuration. Now, however, i want to change the rim size to 24inch, but my top speed reduces (by calculation) to about 48km/hr. I don't want that. So to balance that out, i'm thinking of changing the controller to 60V. I have searched for 60V controllers and have found these on ebay:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=280836209091
http://www.ebay.com/itm/60V-1500W-Brushless-Motor-Speed-Controller-For-Electric-Bike-Bicycle-Scooters-/280836209091?pt=LH_DefaultDomain_0&hash=item41632479c3

these are 2 different sellers. Has anyone ever bought these controllers from these sellers? and i'm really confused about the throttle? Please, read the item description and tell what kind of (full-twist) throttles are compatiable with these controllers?

But first things first; is it really a good idea to upgrade from 48V to 60V? will it damage the hub motor's hall sensors?

Looking forward to anyone's reply.

 

[Punx0r]

I wonder if your current controller would take 60V?

If you identify it one of the experts on here might know

 

[spinningmagnets]

is it really a good idea to upgrade from 48V to 60V? will it damage the hub motor's hall sensors?

I believe the hall sensors run off of 5V from the controller, so you'll be fine. Your hill-climbing torque will improve at the higher voltage and also your top speed will go up. Make sure your controller is rated to run at 60V. Some controllers are made run only on a specific voltage, and others will work in a range of voltages.

 

[dnmun]

you need to determine what type of battery you will be using to get more speed, then modify your current controller or purchase another replacement.

the LVC of the controller you purchase will determine how much charge you can remove from the battery. the LVC is set for use of SLA batteries as the power source, not lithium ion storage.

if you want to use the current controller and upgrade it to higher voltage, that is really simple. just the cost of a few higher voltage caps and maybe an input power resistor change.

if the mosfets in your current controller are the p75fn75 mosfets then they will handle up to 75V. your 48V controller caps are 63V and will need to be upgraded to 100V.

if you go over 75V (60V lifepo4=73V fully charged) then you will need to upgrade the mosfets in your controller also to the irfb4110s.

post up if you wanna do the upgrade. you can buy the 20S lifepo4 BMS from ping, or go lipo like a lotta these guys and then 18S lipo would allow you to use the 75V mosfets.

 

[o00scorpion00o]

I Had great craic with that conhismotor with a beefed up Lyen 12 FET for 5 kw on 66V 16S LiPo

It will really lift the front wheel and do 40 mph or so with the controller set to 120%. You would have to upgrade the phase wires, I highly recommend 12 AWG Alpha Ecowire. It's got really thin insulation and is ideal for hub motors.

You would probably need a new battery also and high power usually means LiPo, or much more expensive and larger LiFeP04 such as A123.

I would save a few hundred on the motor and have some fun with it and make good use of it before spending money on another motor. The conhismotor isn't the most efficient sure. But you could save on a new motor and put it to a better battery.

For 5 kw you might need to go to a 18 fet controller for better reliability especially in warm countries. Go with an infineon controller with a program cable so you can set it to your needs and that of your battery.

If you want more torque with the same battery and controller then the best thing to do is go with a mac 8T it's got a lot more torque than the conhis say at 1kw -2kw. I got 28 mph out of it on a 48 V ping with the controller at 120% setting. The mac would be a lot more efficient.

 

[sheikhuu]

Thank You!

Well, the controller is a Chinese make. I have attached a photo (i admit it's a crappy photo) of the sticker that's on the controller. In front of the label 'Model', it's written 'SYK-48-100W'. I hope that helps.

I'm currently using 4x 12v12Ah Lead-acid batteries as LiFePo4's are out of my budget. :/

I'll try to open my controller and see the type of mosfets inside. Can you please tell me more about voltage caps? I really appreciate the help.

I've also attached a photo of my ebike.

 

[Punx0r]

This is the sort of thing you're looking for:

That's rated very high (450 volts).

 

[sheikhuu]

I'm sorry. I'm a freshman college student and i don't know how a brushless 3 phase controller works. How should i attach a 450V capacitor to the controller? Looking forward to your reply.

 

[Ykick]

450V capacitor is for a tube amp or one of Luke's controllers not the OP.

My 1000W Conhismotor controllers handle 62.5V hot off the charger. A battery from this century will pretty much solve your RPM difference of 26" - 24" motor wheel.

 

[Punx0r]

Sorry, the above image was only intended to illustrate the component and the rating printed on it

 

[dnmun]

I'm sorry. I'm a freshman college student and i don't know how a brushless 3 phase controller works. How should i attach a 450V capacitor to the controller? Looking forward to your reply.

no, you should not do anything until you can afford to upgrade the current SLA to lifepo4 since the only solution available to you involves using a 5th SLA battery on your bike and that is a 48V controller so if you run the 5 SLA down to 40V for the LVC of the controller, then all of the batteries will be severely damaged and your money will be wasted.

the lifepo4 will give you a longer period of use of your ebike at higher speeds than you can achieve with the current batteries. they will last much longer too with no degradation in performance over time. that is the reason for making the investment in better batteries, and then protecting them after you buy them. so if theft is a problem, then the pack is also light enuff to be removed from the ebike and carried inside to charge, otherwise it can be charged on the ebike just as with your current SLA.

 

[Punx0r]

If the chap already has SLAs and has built the bike around them, what's the harm in using them until they need replacing?

The best case scenario is not to buy SLA in the first place, but if you already have them...

A small increase in voltage is going to end up costing $1000 if everything gets replaced...

 

[dnmun]

did you read what i said? he basically would only get one use out of the SLA because as soon as it went to LVC the first time, the batteries are essentially gone. they don't like going to 8V.

if he is in china a 60V15Ah pack will cost about $300, and about $550 delivered here in the US. your opinion may vary.

i have already covered how to add a 60V lifepo4 pack in parallel with the regular 48V pack for a scooter in the thread alastor started.

but this was for a scooter, not a bike:

http://www.endless-sphere.com/forums/viewtopic.php?f=7&t=40048&hilit=alastor&start=30

 

[o00scorpion00o]

Open up the controller and take a few pics of the components. That will give us a better idea about what your controller can take.

maybe it can be beefed up for more current which will give you better acceleration,

But really the SLA is your biggest limitation, I would wait until you can afford LiFeP04 or LiPo.

But the motor itself can take a lot more power, (once you upgraded the phase wires) so the next logical upgrade should be to Lithium, you will not regret it that's for sure.

 

[wesnewell]

First, go to your user profile and fill in your location (country minimum). Now, it won't do you much good to go from 48V to 60V. And if you're using SLA, use them till they are dead, and then go to a 72V controller and lithium battery pack. Here's the controller I use at 100V.
http://www.dhgate.com/72v-1500w-brushless-speed-controller-for/r-ff80808131bbd38d0131bbda55e40253.html
I use 24s lipo with mine now, but 18-24s will work. A 20s pack (74V nominal) will cost you about $125 and you'll need a charger, which can cost anywhere from $25 up, depending on how fast you want to charge. A 5ah 20s pack will get about 15-20 miles at 20mph.
If you just want a couple more mph from what you have now, get a 6V battery and put in series with what you have now. You can still use your current controller. watch voltage and don't run below 47V or you could damage your batteries. Full charge voltage will be around 59V. And that within the specs of your current controller.

 

[sheikhuu]

Thank you all for your help!

Well, where i live the custom duties are pretty high. So high that even a $300 lifepo4 battery pack is going to cost me no less than $600. I get it that SLA are a big limitation but i can't afford lifepo4 right now or even for a couple of years since i'm not earning (i'm a student).

My idea was to add a fifth SLA battery and buy a new controller that operates at 60Volts. I want to leave my current 48V controller untouched. It's just the motor and the compatible throttle i'm worried about.

Sure, when i have the budget, i'll go for LifePo4 batteries and probably a crystalyte or dual magic pie motors. I originally designed my bike around lifepo4 battery packs, specifically 72V 40Ah battery packs. see some of the attached pics. But right now money is the issue. I have enough to buy a new controller and an extra battery.

 

[dnmun]

http://www.ebay.ca/itm/LiFePO4-48V-15AH-Battery-Charger-BMS-Rechargeable-Electric-Scooters-Sea-7-8-Week-/130656251541?pt=US_Rechargeable_Batteries&hash=item1e6bb82e95

 

[sheikhuu]

errr.......seller does not ship to Pakistan....

 

[pchen92]

What is your budget ?
What range do you want ?
Lipo could be fine if you know this chemistry. 3*5s 5Ah (10 miles range) could be good with a small charger 150W, a power supply and a low voltage cut-off.

 

[Punx0r]

did you read what i said? he basically would only get one use out of the SLA because as soon as it went to LVC the first time, the batteries are essentially gone. they don't like going to 8V.

Hmm. If only there was some way to stop discharging before hitting an arbitrary LVC.

 

[sheikhuu]

What is your budget ?
What range do you want ?
Lipo could be fine if you know this chemistry. 3*5s 5Ah (10 miles range) could be good with a small charger 150W, a power supply and a low voltage cut-off.

My budget is US $150 and with the current battery pack (48V 12Ah SLA) my range is about 12 to 13 miles on a single charge. I definitely don't want to end up with a higher speed but shorter range ebike.

did you read what i said? he basically would only get one use out of the SLA because as soon as it went to LVC the first time, the batteries are essentially gone. they don't like going to 8V.

Hmm. If only there was some way to stop discharging before hitting an arbitrary LVC.

My current 48Volt controller already has an automatic power cut-off feature when the battery pack goes below 43.2Volts (that's 10.8Volts per battery). It stands to reason that if i but a 60Volt controller, it will have a cut-off near 54Volts thus protecting my batteries from deep discharge and preserving their duty cycle.

 

[dnmun]

if you do understand why the LVC is there, you can buy one of the cheap voltmeters and just measure the total pack voltage with the 5 SLA and make it a point to stop and recharge when the pack voltage drops to 50V.

that was my concern, that you were not familiar with why the LVC is integrated into the controller function.

the main advantage of going to lifepo4 from SLA is the increased life span of the battery, and the voltage during discharge under load does not drop as much with lithium ion cells as with the SLA because of the peukert effect so you get more useful power over a very very long time by comparison to SLA.

but you gotta go with what you can do now. just make it a point to carry a charger with you along with the 5th SLA and keep it charged up whenever you stop at the 50V level.

nice bike layout. looks like you spent a little effort in creating the cowling for the pack. the sun-thing pack is kinda the cheapest lifepo4 option we can find on ebay here in the states. maybe in time you will make friends at school with someone from china and have enuff cash to get them to buy one for you when they go home and bring it back on the train with them. a pack like that sun-thing pack i linked is about 13lbs, easily carried on the train in a box. that might get you to the $300 level, BOL.

 

[sheikhuu]

the main advantage of going to lifepo4 from SLA is the increased life span of the battery, and the voltage during discharge under load does not drop as much with lithium ion cells as with the SLA because of the peukert effect so you get more useful power over a very very long time by comparison to SLA.

but you gotta go with what you can do now. just make it a point to carry a charger with you along with the 5th SLA and keep it charged up whenever you stop at the 50V level.

nice bike layout. looks like you spent a little effort in creating the cowling for the pack. the sun-thing pack is kinda the cheapest lifepo4 option we can find on ebay here in the states. maybe in time you will make friends at school with someone from china and have enuff cash to get them to buy one for you when they go home and bring it back on the train with them. a pack like that sun-thing pack i linked is about 13lbs, easily carried on the train in a box. that might get you to the $300 level, BOL.

Hey, that's a great idea! I do have friends in Hong Kong and Singapore. I'll get it from them. Thanks! and can you please help me identify how does the throttle connect with this brushless motor controller:

http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... 0836209091

 

[dnmun]

bad link.

throttle has three parts: 1, the ground, 2, the red (usually) 5V power to the hall sensor IC in the throttle, and 3, the hall sensor output, usually green or white but until we can see your throttle leads, no way to tell.

if you have an led indicator that tells you battery voltage at the throttle, that would be a fourth wire, and it will have the full battery voltage. having full battery voltage in the throttle can lead to hall failure of the throttle when it gets wet in the rain, that may or may not be a problem for you. if rain is a problem then don't connect that wire to the throttle.

there is a thread around here about a $15 voltmeter/ammeter that will help you monitor the actual battery voltage, and it will keep track of the amount of charge used as you discharge the pack so it will help you monitor the condition of the 5 SLA when you do it.

learn to carry a charger and use it if you use the SLA and it will increase your range and make the batteries last twice as long. so learn to scout out spots to charge up at your destination. BOL.

 

[sheikhuu]

Thank you so much for your help!

Sorry about the link. Here, try this one:

http://www.ebay.ca/itm/60V-1500W-Brushless-Motor-Speed-Controller-Electric-Bike-Bicycle-Scooters-/280836209091?pt=LH_DefaultDomain_0&hash=item41632479c3

Yeah, i'll look into that voltmeter/ammeter display. Currently using a analog ammeter and a bar graph display to show voltage. See the attached pic.

I have alot of free space inside my bike. So, incorporating an on-board charger isn't going to be a problem.