New guy with a 48V question

[MikeSSS]

Hi, I'm MikeSSS in San Antonio, TX. I'm 190 lb, comfortable speed is about 9 to 15 mph, average energy use is about 15 to 20 Wh/mi, average watts are about 100 to 180, all this is based on charging data. We have some climbing here in SA.

Edit to add, the hub motor is an Aotema, brushless, sensorless, 3 wire, direct drive front hub motor.

My ebike is a Japanese mtb, 3 chainrings, 6 cogs, with an older Aotema brushless direct drive front hub motor, battery is 36V gel cell made of three 12V, 12Ah batteries. One of the three batteries is sagging after only 4 miles or so, it has 10.5V at the end of about 8 miles but voltage rises with resting time, the other two batteries have more like 12.4V at the end of the same ride. Rides of 14 miles have a lot of sag in the weak gel cell battery but not the two good batteries. Power is adequate for all but climbing, the motor is just a couple degrees over ambient after 4 miles at 14 mph, with some climbing. I plan to replace the weak battery with a UB 12120, but also want a lighter battery pack, the current pack is just too heavy to be fun to use.

Miles to date are about 200, perhaps higher. The Aotema front hub motor, and controller have been totally reliable.

I use a lot of Lipos for RC planes, multi rotors, crawlers and boats, but don't have any experience with Li ion batteries, other than cell phones. I'm looking at Hobbyking Lipo, 6s, 16000 mah, 22.2V batteries, two would give 44.4V. http://www.hobbyking.com/hobbyking/store/__66310__Multistar_High_Capacity_6S_16000mAh_Multi_Rotor_Lipo_Pack_EU_Warehouse_.html

Is there a 48V controller that would work with the Aotema front hub motor and 44.4V Lipo batteries? I'd especially like to use a half turn twist grip throttle, the thumb throttle on my Aotema rig is just too different than the throttles on the motorcycles I've had. It would really be good if the new controller would also work well with Li ion batteries in the 48 to 52 volt range.

Well, that's it, replace Aotema 36V controller and thumb throttle with a 48V controller and half turn twist throttle and use a 44.4V Lipo battery and also use 48 to 52V Li ion batteries.

This site is most excellent, it is fun to read and very informative.

Thanks,

Mike in San Antonio.

PS, I really like titusmc's bike: https://endless-sphere.com/forums/viewtopic.php?f=6&t=81195

 

[Drunkskunk]

Welcome to the forum.

Normally I try to steer people clear of Lipo for safety reasons, but it sounds like you know how to use them. I use them on several bikes. It's amazing how much better a bike performs even with the same sized Lipo as the original lead.

Before you go to far with a new controller, you might want to check yours. Some "36v" controllers are only limited by their settings for low voltage. If you ignore that feature, they were fine to run up to a peak of 63 volts. You can confirm this by opening them, and reading the voltage rating on the capacitors. If they are 63v or more, then you're fine upto 55.5v of Lipo. You'll lose the low voltage cut off, so you'll just need to monitor your pack voltages while you ride.
The usual low voltage cut off of a 48V controller is 42 volts. That would cut your 44.4v Lipo off when you hit 3.5v per cell.

Aetoma/W.E. made a brushed and a brushless motor. Not sure which one you have, but the brushless version can run just about any brushless controller. a cheap Ebay controller could serve, but you could also run a higher end programmable unit and unlock better performance from your motor. I'm a fan of the Infineon based controller paired with a direct connect Cycle Analyst.

 

[Rassy]

I didn't see if you mentioned that your hub motor is brushed or brushless. I had several of the Aotema 36V motors and controllers, all brushed, and eventually started running them with 48 volts with no alterations or issues except for disconnecting the LEDs on the throttle which became super bright, would probably have burned out anyway, and no longer gave valid battery info.

When I first tested them with 48 volts it was with 4 of the 12V 12AH SLAs, but later with 48V Pings, which came off the charger at about 57 Volts. Two of those hub motors are still in service on other folks trikes at about 10 years old, and have never required any service. They both use 48 Volt Pings.

As a side note, I still have one of my original 12V 12AH SLA batteries that I use to pump up an air mattress a few times a year. Most of those batteries died after a few years, but this one is now charged with a pulsing charger that is designed to "restore" Lead Acid batteries, and it is performing great and holds its charge for months at a time.

 

[MikeSSS]

Yep, forgot to mention that the Aotema is brushless, sensorless, 3 wire, it is a front hub motor, and is probably a few years old. I've been using it off and on for a year.

Because of RC I use a lot of Lipo batteries, but none have enough capacity to run an ebike. Thing about the HK lipos I'm looking at is that they are cheap and can provide plenty of power on the climbs.

I'll look into the caps on the controller, it may do just fine.

 

[wesnewell]

By 3 wire, I assume you mean 3 phase wires, usually green, yellow and blue. Are there no other small hall sensor wires (5) coming from the motor? If not, then you have to have a sensorless controller. In any case a 36V controller should work fine with 12s lipo even if it only has 50V caps inside. Charged voltage of 50.4V. No 36V controller will have less than 50V caps, and many will have 63V. You could also run 10s lipo without a problem, other than LVC may be too low for it, as it would certainly be too low for 12s. Most 36V controller have alvc of ~30V. I'd recommend 35V for a 10s pack of rc lipo.

 

[motomech]

Just to expound on drunkskunk's reply;
Multistars are great for low-powered systems like yours.
They are often on sale and it's been awhile since HK has any of their Lipo on sale, so it's about due. I guess you know how HK works.
My last order, I went w/ 4) of the 6S/10Ah bricks configured 2S/2P for a 20Ah pack. It was easier to fit 4 bricks into my triangle bag rather than 2 larger bricks. Don't shy away from 2s/2P to get the capacity you want if 2S/1P doesn't work out.
The regular Turnigy 20C is good too if they go on sale first.
DS is exactly right on a 48V controller's LVC. With Lipo, you need a good solid LVC(no alarms)and 42 Volts is perfect for 12S, so stay with that. It will get your top speed over 20 mph and you will quickly get to liking that :lol:
I think this 9-FET 19A controller would be a good match;
http://www.ebay.com/itm/36V-48V-500W-9MOSFET-ebike-Electric-Bicycle-Brushless-Motor-Controller-LED-/222181208529?var=&hash=item794f452464
It comes with the simple 810 display that allows system on/off, 3-speed limiting and PAS(which you should try and use).
As for the throttle, I prefer half-twists, in particular, the left-handed ones. Since the chain ring is not shifted with a motor system, I remove that shift and put the throttle there, leavingthe right side for unfettered shifting. Ebike CA has them;
http://www.ebikes.ca/shop/ebike-parts/throttles/t-lhtwist.html
Lastly, you will want to monitor your pack capacity is some way. These days,I only use a Voltmeter, it tells me what I need to know. You can use a cheap mini-meter off Ebay, but I like the flat meters from Luna Cycles;
http://lunacycle.com/batteries/gauge/luna-voltage-meter/

Hope this helps.

 

[MikeSSS]

Motormech: The controller linked has EABS and it looks like it can't be disabled since it is on the PCB. Here is a link to an alternative controller that does not mention EABS on the PCB, I don't want EABS.
http://www.ebay.com/itm/36V-48V-350W-9MOSFET-ebike-Electric-Bicycle-Brushless-Motor-Controller-with-LED/222181208533?_trksid=p2047675.c100623.m-1&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D37470%26meid%3D6bcf2e27befe4042bbeb765b319635b2%26pid%3D100623%26rk%3D3%26rkt%3D6%26sd%3D222181208529
I'd really like to have a 42V LVC in the controller but using the Luna voltage display with my controller would be fine for a while.

My bike has traditional cantilever brakes, the levers do not have switches to turn off motor power. Ebike brake levers are made for Vbrakes, to use them I'd have to change the brakes out, which I do not want to do. Can I not use ebrake cutoff simply by not connecting the plug to the ebrake levers? Eventually I'll change the host bike to something like a Townie that does have Vbrakes.

Well, I need to do more battery planning, thinking at the moment is Lipo 12s, with high enough capacity to ride the "Death Loop", a 26 mile ride that has a couple short climbs of over 6% gradient.

My most recent rides have used 15 and 16 Wh/mi and included some climbs. Planning the Death Loop budget at 20 Wh/mi and 27 miles, gives 540 Wh needed, at 44 volts this requires 12 Ah of battery net. If 60% battery capacity is used, then 20 Ah gross battery capacity is needed, to have safe reserve. Needed battery capacity could be further reduced by limiting speed on the flats to 10 mph and using aero bars, this is how I rode it using pedal power.

Does the controller linked above and perhaps the use of four 6s, 10Ah Lipos seem OK for the planned ride?

I'm a little concerned about using a direct drive hub motor for the Death Loop but switching to a gear drive hub motor or a mid drive would require more money and that is never a good thing.

Any and all comments and advice are welcome.

Thanks,

MikeS

 

[motomech]

The controller linked has EABS and it looks like it can't be disabled since it is on the PCB. Here is a link to an alternative controller that does not mention EABS on the PCB, I don't want EABS.

What's EABS
Seriously, I don't why they show that(and all genaric controllers do). I doubt it's even there and I don't know anyone who has tried it. Not to worry.

I'd really like to have a 42V LVC in the controller but using the Luna voltage display with my controller would be fine for a while.

Yeah, Luna has some kool stuff. Lov their h.light(on 44.4 Volts, oh yeah).

My bike has traditional cantilever brakes, the levers do not have switches to turn off motor power. Ebike brake levers are made for Vbrakes, to use them I'd have to change the brakes out, which I do not want to do. Can I not use ebrake cutoff simply by not connecting the plug to the ebrake levers? Eventually I'll change the host bike to something like a Townie that does have Vbrakes.

Ebrakes smeebrakes. If you want them, you need one of these;
http://www.elifebike.com/peng/iview.asp?KeyID=dtpic-2014-19-JMEJ.3MWYN
I don't think ELB sells these on their website, so if you want them, you might as well order the controller from ELB directly.
But unless you use the cruise, you don't need them. They would be nice for PAS, as there is a 2 or 3 second "over-ride" when you stop pedaling(cheap controllers do this). I don't use ebrakes, but my hydro. discs will over-power the motors and stop the bike no matter what. Now the Aotema is no power house, but then again your brakes sound weak.
Speaking of the Aotema, I almost bought one once because I think they look cool, so I know a little about them. They are the smallest DD motor avail., and as such, they are a little down on torque, so be careful on the hills to not let it lug down. Never let the motor speed fall below half of the no-load speed. Or to simplify, never let the road speed fall to less than half the top speed.

My most recent rides have used 15 and 16 Wh/mi and included some climbs. Planning the Death Loop budget at 20 Wh/mi and 27 miles, gives 540 Wh needed, at 44 volts this requires 12 Ah of battery net. If 60% battery capacity is used, then 20 Ah gross battery capacity is needed, to have safe reserve.

I don't bother with the calculations. I've been riding this bike for so long, I just know that I will get about 1 1/2 miles to one volt useage with a 10Ah pack, 12 miles/10Ah., 24/20Ah., etc. I carry 25Ah and never even get that close to LVC. It's easiser on the Lipo that way. A really fit rider could probably get 2 miles/Volt with 10Ah. I pedal moderately around 20 mph. in the flat. Hill drop range dramaticly.

Needed battery capacity could be further reduced by limiting speed on the flats to 10 mph and using aero bars, this is how I rode it using pedal power.

Sounds boring. What is the point of going 10 mph with an ebike? They way it's done with cruise control or PAS, is set the speed almost to where you want it w/ the speed limiter(say 15mph, for best economy)and pedal 1 or 2 mph above that.
IMO, the best assist Ebike allows you input(and exersise), while maintaining a higher avg. speed(mo0re fun)and shorter elapsed trip duration.
Carry enough battery to do that!

How will you charge?
(Hint, bulk charging is the way to go)

 

[dogman dan]

FYI, the controller usually part of the aotema kit can handle 48v fine. 63v fully charged is the max. YOU DO NOT NEED A NEW CONTROLLER.

So 12s will work fine,, or 14s. 15s possible, but pushing that max a bit. The stupid lights on the throttle won't work for 48v, but they will handle the voltage and be an on off indicator.

13 or 14s can make bulk charging easier, since chargers set for that voltage are common.

Get at least a volt meter on the bike, for using lipos. you need to know when to stop, when the pack is at 3.5v per cell average. Preferably, size your pack so you never have to worry too much about it, and tend to return home with 3.7v or more.

 

[d8veh]

Although a little more expensive, these controllers with the LCD will give you everything you want. They give you a very good experience if you use the pedal assist function because they use current control rather than speed control. You can choose any one of 6 currents at any time by pressing a button on the handlebars. The currents are slightly adjustable and range from zero to maximum (22A). That means that you can pedal along on level 1 with a constant 60w of assistance, and when you get to a hill, you press the button for level 4 (say), which steps the power and torque up to say 400w. You can use a throttle with them, but you rarely need to. The throttle works alongside the PAS and can be used at any time to give instant speed control, just like any other controller. The LVC is also slightly adjustable, though just about all 48v controllers have their LVC set in the correct range for 12S lipos. Whether it's 38v or 42v doesn't make much difference because you're in the range where the voltage is dropping very quickly. Once down to 44v, you need to be close to home. The LCD will show the voltage, so you can see what's happening.

https://bmsbattery.com/ebike-kit/648-s09pw-easy-assembling-waterproof-connector-kit-ebike-kit.html?search_query=s09p&results=10

or this:

https://bmsbattery.com/ebike-kit/553-s09p-500w-torque-simulation-square-wave-controller-ebike-kit.html?search_query=s09p&results=10
https://bmsbattery.com/ebike-kit/670-s-lcd3-lcd-meter-for-s-series-controlers-ebike-kit.html

Download and read the pdf manuals at the bottom of the LCD listing to see all the functions, which are optional. defaults should be OK.

 

[d8veh]

One important thing that nobody mentioned. When you change to 48v, your motor won't be very efficient at the speed that you go, so your wh/m calculations might be quite wrong. If you want to travel at the same speed, you should stay at 36v and get a controller with a higher current rating for more power.

 

[dogman dan]

It will remain efficient at the low speeds if the load is light. like on the flat.

But on the Austin hills, 48v or 36v, the most efficient way to get up them is to gun it full throttle, pedal briskly, and climb them as fast as possible. This is likely to still be no faster than 15 mph. Below that speed, the motor will stall, make heat, and climbing the hills at 10 mph is a bad bad idea.

If you do change controllers, one with slightly higher current than your 22 amps controller would make climbing the hills even faster, and more efficiently possible.

But I still say,,, you don't need to change anything just yet. Perk that thing up with 44-48v lipo, and it will run fine. If you want to upgrade, then upgrade to a rear motor, display, the works.

Not sure how many miles others ran that exact kit, but I did about 3000 miles on one. Climbed many a hill, loved how it ran on 48v.

Missed the throttle thing earlier,, get a three wire twist grip throttle, cut and splice wires to get your aotema type plug on it, ignoring the purple wire that runs the lights on the original one. The connector on the aotema throttle is usually a mini jst.

You can also convert that original to a half twist. Glue a short piece of 1" PVC pipe on the throttle. not too much glue, regular pvc cement.