Bought a used emmo proton testing batteries..

Domhelp

100 mW
Joined
Oct 2, 2018
Messages
49
I fully charged the batteries and the resting voltage was about 80 volts. After about 10 km Under full load from a stop voltage was 72 and after 20 km full load voltage was 68 after 30km full load was 65.5. Resting voltage was always above 72. After 40 km battery was dead and resting voltage was 70 and 63.5 under full load.
It was 8 degrees Celsius. Just wondering about condition of batteries compared to when new. They are 72 volt 30amp hour lead acid. Thanks.
 
I forgot to mention that there were a lot of hills and high-speed riding
 
I did some research on SLA batteries. In a 12 volt battery once your resting voltage is 12 volts your battery is pretty much dead. Manufactures recommend to not go below 11.8 volts but some users say you can go down to 11 volts as an absolute limit. The deeper the discharge the less cycles your batteries will give you. My resting voltage after 40 km was at 70 which is about 11.7 volts per cell which means the batteries were dead but I did not severely discharge them. I guess there is built in protection for the batteries. As far as my distance I am not sure what other owners are getting in the real world. Do emmo proton owners really get 60 to 70 km?
 
How many batteries are in there? 80v seems a bit odd.

It sounds like they are working reasonably well. Lead acid really sucks though, and you should eventually try to upgrade to lithium EV batteries. Used ones from cars are getting easier to find these days.
 
You're right that's after the batteries had been sitting for a couple of days. Right after a charge I think they were closer to 88 volts and there are 6 12 volt batteries. I intend to go the lithium root. Still learning and and considering making my own pack.
 
88V sounds about right for 6 12v batteries.

Keep watching the used EV batteries. Chevy volt and Nissan Leaf are fairly common, but there are lots of others out there. It makes such a huge difference in performance. About 21 series Li-ion cells would be close to your current setup.

Post a picture of the bike if you get a chance. I don't think I've ever seen one of those.
 
20181001_133529-1008x490.jpg20181001_133538-1008x490.jpg20181001_161751-1008x490.jpgHere are some pics. Rear fender from a grom,handle bars changed not sure from what and headlight from some type of Jeep. I want a little more acceleration. I know battery will help but I can tell that the controller is limiting amps on acceleration so I need to see if I can modify controller or if it needs to be replaced. Will change motor if necessary but I don't need much of an improvement to be happy. Controller is supposed to be 45 amp 24 mofset and don't know if it can be modified. Controller stamped with Yufeng. Took it for a ride started raining it needs a bath.
 

Attachments

  • 20181005_201906-1008x490.jpg
    20181005_201906-1008x490.jpg
    74.3 KB · Views: 2,307
I love this thing and it's great transportation. Unfortunately it's getting cold now so I will not be using it much.
Previous owner did a great job in the looks department . To improve performance I plan to get a lithium battery. I may get an 84 volt battery and keep this controller or get a 72 volt battery and buy a better controller. What do you guys think is the best way to go to get a little bit more performance? Top speed is good but I want a little more acceleration from a stop or low speed. A lithium battery I believe would be about 90lbs lighter, that alone should make a big difference. So much fun can't wait for good weather.😁😁😁😁
 

Attachments

  • 20181011_162538-1008x490.jpg
    20181011_162538-1008x490.jpg
    141.4 KB · Views: 2,176
  • 20181011_165257-1008x490.jpg
    20181011_165257-1008x490.jpg
    76.6 KB · Views: 2,176
  • 20181015_172105-490x1008.jpg
    20181015_172105-490x1008.jpg
    133.4 KB · Views: 2,176
G'day.
Instead of buying a 72V battery & controller first, I'd by the 84V batt. If the controller can't handle a 12V increase & blows ( doubt it ), then buy a better controller.

AussieRider
 
AussieRider said:
BTW, very nice machine!

AussieRider

Thanks
I intend to increase the voltage first but unfortunately there is no room for another 12 volt 30amph battery.
Not sure that I can justify spending about $1500 on a lithium battery as the machine is fun as it is. I may spend the money towards a mid drive mountain bike build as this way I will have two very different style of ebikes.
 
Hey Dom,

Paul here from Kijiji. One other thought I had that may help improve your bike's acceleration/torque would be to perform the shunt mod to the controller. As we talked about before; I suspect it is being limited to 500W to conform to Ontario laws. If the controller can't be programmed; the shunt mod would trick the controller and allow it to use more battery amps (see the link).

Just be aware you will consume more juice from the battery. I highly recommend fitting a power meter on the bike so that you can see how many amps the controller is really drawing from the battery. This will be especially useful if you decide to shunt mod the controller.
 
Hi Paul,
The shunt mod was done. It is fast enough and I have to decided to leave it be. Any faster and it would be dangerous for city streets. Over the winter I will build a mid-drive mountain bike that I can mess around with off road. This bike is great transportation and fun but I need something for the dirt and bad weather. A power meter is a good idea.
 

Attachments

  • 20181104_161143-1008x490.jpg
    20181104_161143-1008x490.jpg
    143.3 KB · Views: 2,019
I bought it with the shunt mod already done. I am not sure if the shunt mod on this controller increases acceleration or just top speed. I was under the impression that this shunt was a type of governor that would limit speed by limiting current once it reaches a set speed. An amp meter measuring current with or without the shunt (shunt is on a switch and only switched on off road) would tell me what effect the shunt is having. From feel the shunt does nothing below a set speed but I may be wrong. Maybe the controller can be modified in other ways. Definately
Need to measure amps.
 
The shunt mod increases the current limit, which would give better acceleration but not much change in top speed. Some controllers have a speed limitation independent of current but the shunt wouldn't change this.
 
Ok thanks

My top speed doubles but acceleration, I believe, does not change with the modification. so maybe it's not a shunt but some other modification. Maybe one day I will open the controller and have a look.
 
Installed an amp meter. Only about $30 on Amazon. Comes with an 100 amp shunt and does voltage up to about 90v I think. Only issues are it's not entirely waterproof and there is no mounting hardware. I am using velcro to mount and can remove it if necessary so it works great for me. Does voltage, watts, amps and amph.
 

Attachments

  • 20190208_183103-1612x784.jpg
    20190208_183103-1612x784.jpg
    141.9 KB · Views: 1,655
Nice meter, I'm curious to see what your max current draw is on that bike with SLAs. I'm not sure what the back of the meter looks like; but liquid electrical tape might help with waterproofing it.
 
pwd said:
Nice meter, I'm curious to see what your max current draw is on that bike with SLAs. I'm not sure what the back of the meter looks like; but liquid electrical tape might help with waterproofing it.

According to the meter just over 45 amps. One day I will compare it to a clamp on meter to see accuracy. So I guess that explains why my "500 watt" scooter does over 60kmh. The only modification is the governor bypass and this does not appear to affect max amps.
 
Very nice; 3kw should get you up to speed fairly well on that bike.
 
If the motor is anything like the EM-1 then you may find little increase in going to a slightly larger pack. The motor is saturated already and you just warm up the motor and see a little less voltage sag. The actual controller is okay, not the best but not the worst. The swapping the motor out is probably going to yield best results
 
I weighed the batteries on my proton. It has a 72v 30amph battery. Each 12v battery weighs 23 lbs, thats 138 lbs in total and more than half the weight of the bike. My 72v 20amph lithium battery weighs 18 lbs. If I install this battery I will shed 120 lbs and probably have higher voltage under load. This should transform the bike, Something to look forward to. :bigthumb:
 
Back
Top