M-350 - no power to display

[Kerrith]

Stopped while driving with full batt. The LED screen showed nothing. I've removed and reinserted the batt. When I press the on button on the batt and press the Mode button on the handle bar, as I've been doing for 2+ years, still nothing.

Update: 10/20/25

Received new controller but same problem. The batt is fully charged.

Got suggestion?

 

[Chazmo]

Sounds like maybe a loose/broken connection somewhere. Stupid question, but is the battery turned on? Do you feel any heat generated from the battery if you place your hand around it in various places…?

Are you dead in the water or is it just that the display isn’t turning on?

 

[Kerrith]

Full Batt. I unplugged and replugged the wire into the display. Batt temp feels normal.

Re: "...dead..." I was riding and it simply stopped, the display went blank. I had to walk it home.* The M-350 is about two-years-old with about 400 miles on it.

* I am disabled so I never pedal.

 

[Chazmo]

Oh, I’m so sorry I am not able to help you, Kerrith. Unfortunately, there are many reasons why this could be the case.

My best wishes finding out what’s wrong and repairing it.

 

[Kerrith]

Thanks Chazmo.

 

[Kerrith]

Thanks Chazmo. Any idea about of where to get an answer?

 

[Chazmo]

Kerrith, when a bike just shuts off like that and the display won’t power up, that generally means there’s something wrong with your battery. There are lots of other possibilities, but the first thing I’d do is put the battery back on the charger and see if it charges at all. It should charge a bit if you were riding with it for a bit.

If it charges, let it charge a while and make sure the battery isn’t getting hot — the charger will, but the battery shouldn’t. If the battery gets hot it could be dangerous since one of the cells in the battery could be bad, Kerrith. So please be careful, and do the charging somewhere that won’t be a problem if the battery flares up. Unplug the charger if it’s getting excessively warm.

This is the first step in figuring out where the problem might be. If you’re not comfortable doing this yourself, maybe you can seek out the help of a bike store near you?

 

[Kerrith]

Thanks Chazmo. I did that, it was so full that it stayed green, it didn't charge. I left it for 30 mins and same room temp. Also I took it out and reinserted it.

Do you know where to post to get more help?

Re: "store" No car. No store.

 

[Jeremy McCreary]

Do you know where to post to get more help?

Try the subforum for your bike's manufacturer here:

Discussion by Brand & User Reviews

Discuss electric bikes by brand and if you already own one, share your upgrades and insights including user-created reviews or links and summaries of third party reviews

forums.electricbikereview.com

To help us help you, provide as much info about the bike you actually have as possible — including make, model, year, type of assist, etc. Sure I'm not the only one who knows little to nothing about the M-350 just from that name.

 

[Chazmo]

Thanks Chazmo. I did that, it was so full that it stayed green, it didn't charge. I left it for 30 mins and same room temp. Also I took it out and reinserted it.

Do you know where to post to get more help?

Re: "store" No car. No store.

I think the fact that the charger is staying green is implying that your battery is bad, Kerrith. No guarantee though. Can you get a second battery to test the theory?

One other thing… Are you sure your charger was not on a switched outlet? I know, it seems like a silly question, but I’ve been confused by that before. My charger turns green immediately (on power from the battery) if the wall socket is off and has fooled/worried me before. If the battery is taking current than the charger should turn another color. And, since you were riding on this battery, it should be taking some charge.

Yeah, sorry, other than contacting the manufacturer or a local bike shop, I don’t know what else to tell you. Good luck, Kerrith!

 

[Kerrith]

Thanks for the suggestions Chazmo. Power to charger is confirmed.

Re: "And, since you were riding on this battery, it should be taking some charge." It was less than 100 yards before it stopped from a full charge.

I also have an M-340 that's having a twist throttle problem. Display OK, just no go. Unfortunately, the batts between the two models are not interchangeable; a big disappointment; I bought the second trike for emergency part-swapping.

 

[Chazmo]

Ugh, problems with both trikes… Sorry to hear that! I have a spare parts bike that I raid (frequently) to supply needed parts to my running bike.

I didn’t realize that it was only operational for a tiny bit. That is very peculiar. Can you look at the battery pack and see if it has fuses that you can access? If so, that’s a possibility too. Finally, does the battery itself have an on/off switch? And, can you tell if you switch it off and on whether it’s turning on? Mine has a power display so I can tell. If it’s just dead (and it’s supposed to have a gauge or something) then it’s still probably the battery that’s at fault.

 

[Kerrith]

Ugh, problems with both trikes… Sorry to hear that! I have a spare parts bike that I raid (frequently) to supply needed parts to my running bike.

I didn’t realize that it was only operational for a tiny bit. That is very peculiar. Can you look at the battery pack and see if it has fuses that you can access? If so, that’s a possibility too. Finally, does the battery itself have an on/off switch? And, can you tell if you switch it off and on whether it’s turning on? Mine has a power display so I can tell. If it’s just dead (and it’s supposed to have a gauge or something) then it’s still probably the battery that’s at fault.

Hi Chazmo. Success with the M-340. I swapped the M-350-A's twist throttle and the M-340 works now.

I'm 87 (memory problems) and haven't used either trike for a couple months so I forgot how the M-340 key works. I can't get the display to turn off, even if I remove the key, however the display turns off after about 5 mins. Is this the way it's supposed to work? I lost my manual so I don't know how to remove its batt.

Much thanks for your support.

 

[Chazmo]

Oh, that’s great, Kerrith. Glad you’re back in business!!!!! Sorry, I couldn’t help you more with the other trike.

Yes, the bike should turn itself off after a certain amount of inactivity. Some bikes can be programmed for a specific amount using the display; I don’t know about your trike.

If you have a local bike shop, maybe they can help you fix the other bike. Best of luck!