~$1,000 China Electric "Grom" motorcycle review, 68kph

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BahamasBiker

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The photos show the battery when "full" and another after a 45 km ride. Can someone calculate the range of this bike, if the battery is to not go below 3.1V per cell? There are 24 LIFEPO4 cells in this upgraded bike.

This is a review of a Chinese electric motorcycle, made to look like the very, very popular Honda Grom motorcycles.

Sells in China from USD$500 (one vendor's website, which I saw once, but cannot find again) to USD$1,000 (Alibaba) with SLA lead-acid batteries.

One China vendor's website says production capacity is 20,000 units per year.

My friend's "electric Grom"

What's bad:

View attachment 2



CAM05369_wm.jpg

[moderator edit to format pics]
 
REVIEW CONTINUED ...




This opinion review is after 55 kilometers of riding this Chinese “honda grom” -looking electric motorcycle.





WHAT'S BAD:

Jumpy takeoff from a stop. Jerky, until 20kms speed.

No under-seat storage. Probably have to find Honda Grom aftermarket saddlebags for cargo.

No hooks for helmet-locking.

The welding seems very crude, probably done by hand, where visible, in one place.




WHAT'S AWESOME:

The price is right! Even with shipping cost to the Bahamas or Jamaica.

Sizzling ride. Goes up steep hills at 40+ kph.

Hub motor does not get hot, even after a steep hill.

Honda 'Grom' styling is a crowd-pleaser. Almost everybody wants one, even teenage girls!

Comfy ride, good suspension.

Has motorcycle tires, won't get flats easily like bicycles.




WHAT I WOULD LIKE TO SEE:

3-speed electronic transmission (switch) like the ones found in my mate's China 'Vespa' clone electric scooter.

Regen braking, to save wear on disc pads, and for safety.
 
OTHER FEATURES OF THIS CHINESE 'HONDA GROM' ELECTRIC MOTORCYCLE:

It is taller than the real 125cc Honda Grom gas motorcycle.

Kickstand safety switch prevents operation unless kickstand is up.

Motion sensing alarm/remote trigger. Alarm also immobilizes the wheels from moving.

Handbrakes act as an electric motor kill-switch, for safety.

Fit and finish seem very good.
 
UPDATE - IS THIS FLAW OR FEATURE?

The headlight has a projector-beam lens, probably for style, but is not a real projector bulb, just a regular one. However, there is no “high” beam, or perhaps the wiring or bulb isn't working. On “high beam”, only two weak spots light up the sides of the road.
 
You should expect while charging the 24s LiFePo4 battery around 86.4V of max voltage at the final charge stage (3.6V per cell). And after disconnecting the charger around 81V of resting voltage (around 3.4V per cell).

To guess the range on LiFePo4 batteries is something pretty difficult, because the discharge curve is indeed almost flat between 95% to 5% of SOC at around sustained 3.2V (depending on discharge rate)

So you must expect around 77V most of the battery cycle and then a relatively appreciable voltage drop. So if you doesn't have battery specifications, you must make more measurements in order to calculate.
 
Hi Nobuo, you're right about the 77V "cliff" where the performance drops.

The circuit breaker tripped "off" while going up a steep hill. End of ride voltage: 76.5V. It could get up that hill, and even taller hills, when voltage was >79V.



REVIEW UPDATE:
-------------------

- The range is 40 kms in real world city/hilly riding, crossing two major bridges included. (With LIFEPO4 battery upgraded from SLA).

- The dashboard's "fuel gauge" is useless, always showing full.

- Would not recommend this to a newbie rider because of the fast-jerky take-offs from a stop.
 
More pictures?
 
BahamasBiker said:
Hi Nobuo, you're right about the 77V "cliff" where the performance drops.

The circuit breaker tripped "off" while going up a steep hill. End of ride voltage: 76.5V. It could get up that hill, and even taller hills, when voltage was >79V.
Click to expand...

there is no circuit breaker. your battery has a BMS that detected one cell dropping in voltage low enuff to cause the BMS to turn off the current flow from the battery to protect it.

we may be able to help you learn how to balance the battery so you can get more storage capacity and that would increase the range and reduce the battery pack total voltage at the point where one of the cells hits the LVC.

post up pictures of your battery and charger if you wanna work on it.
 
Nobuo said:
You should expect while charging the 24s LiFePo4 battery around 86.4V of max voltage at the final charge stage (3.6V per cell). And after disconnecting the charger around 81V of resting voltage (around 3.4V per cell).

To guess the range on LiFePo4 batteries is something pretty difficult, because the discharge curve is indeed almost flat between 95% to 5% of SOC at around sustained 3.2V (depending on discharge rate)

So you must expect around 77V most of the battery cycle and then a relatively appreciable voltage drop. So if you doesn't have battery specifications, you must make more measurements in order to calculate.
Click to expand...


The circuit break tripped. To un-trip, had to switch the circuit breaker to "off", then back to "on".

This was the voltage when the bike stopped completely.CAM05818_wm.jpg
 
CAM05780_wm.jpg
Arlo1 said:
More pictures?
Click to expand...

This China "electric Grom" beside some regular gas motorcycles, for comparison.

The white bag on the handlebar is for groceries. Yup, this is a grocery-getter.
 
dnmun said:
BahamasBiker said:
Hi Nobuo, you're right about the 77V "cliff" where the performance drops.

The circuit breaker tripped "off" while going up a steep hill. End of ride voltage: 76.5V. It could get up that hill, and even taller hills, when voltage was >79V.
Click to expand...

there is no circuit breaker. your battery has a BMS that detected one cell dropping in voltage low enuff to cause the BMS to turn off the current flow from the battery to protect it.

we may be able to help you learn how to balance the battery so you can get more storage capacity and that would increase the range and reduce the battery pack total voltage at the point where one of the cells hits the LVC.

post up pictures of your battery and charger if you wanna work on it.
Click to expand...


This guy keeps on providing bad information on this forum. He should be ignored.

There IS a circuit breaker.
 
BahamasBiker said:
dnmun said:
BahamasBiker said:
Hi Nobuo, you're right about the 77V "cliff" where the performance drops.

The circuit breaker tripped "off" while going up a steep hill. End of ride voltage: 76.5V. It could get up that hill, and even taller hills, when voltage was >79V.
Click to expand...

there is no circuit breaker. your battery has a BMS that detected one cell dropping in voltage low enuff to cause the BMS to turn off the current flow from the battery to protect it.

we may be able to help you learn how to balance the battery so you can get more storage capacity and that would increase the range and reduce the battery pack total voltage at the point where one of the cells hits the LVC.

post up pictures of your battery and charger if you wanna work on it.
Click to expand...


This guy keeps on providing bad information on this forum. He should be ignored.

There IS a circuit breaker.
Click to expand...

How do you switch On and Off the circuit breaker?

When you mention "circuit breaker" is it an independent board from BMS board?

Battery protections are always BMS boards that are usually installed within the battery pack or just next to. BMS's has not exactly the common physical circuit breaker, they just switch off their always opened transistors (MOSFETs) gates, so the current can't flow. Is what dnmun possibly were refering to! :eek:
 
CAM05915_wm.jpgHere's what Chinese circuit breakers look like. (Some cheap scooters, like the low end GIO's, do not have a quality circuit breaker like this.)

Always found under the saddle, from what I've seen.
 
Someone asked for closeup photos. Notice the "dished" disc brake on this e-Grom. The Honda Grom's is very different.

 
Nice 'boo-ya' on the circuit breaker lol. Imo, the bms limited current causing breaker to turn off?
Gfci commonly works this way, it needs power to remain on.
On the rust, just start using a bit of oil. The exposed metal will stay happy if it can be allowed to absorb some.

Also, nice thread and coverage so far, thanks! These bikes seem pretty cool!
500 is pretty darn cheap! A link to alixxxx would be great.
 
Dauntless said:
BahamasBiker said:
skylinefeb75 said:
Please can someone post up a link to where these can be bought???
Click to expand...

Here's the company that sells for $500.

On Alliexpress(?) for $1,000
Click to expand...

We still need a way to actually get to the page.
Click to expand...
http://cnsaichi.en.alibaba.com/product/60224417940-801206539/2015_new_products_72V20Ah_2000W_electric_motorcycle_electric_motor_scooter_MSX.html
 
What size are the wheels? Can you take some pictures of the handlebars and cockpit?
 
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