New bike won’t start

[Dyanne78]

Help! My husband purchased a Maxfoot MF-30 Trike for me for Christmas and for himself an Maxfoot MF-18. Here in Michigan we have great trails to ride but we have to make hay while the sunshines and the cold is at bay. We’ve had a fabulous March so he assembled mine and it is working great. Unfortunately, he assembled his MF-18 and after the briefest of rides (30 seconds) electrical power failed. Display went blank. Verified the pack output is at 48 Volts (Voltmeter reading). Verified everything is plugged in, seated correctly etc. He is an electrical engineer who has worked on batteries so he needs to know where to go with this issue. There are no diagnostics on the net, display is blank, no fault codes. Support is excruciatingly slow. They have answered each email in the middle of the night with an unhelpful response to check what we already have. As I said, we have a short season and are so anxious to get to riding. Does the support team ever call customers, that would expedite things. Anybody with any thoughts or advice?

 

[indianajo]

I checked the bikes by brand threads, and there is a maxx brand but no maxfoot brand. Looks like your phone number is your only support.
If I didn't have a warrenty I would skin the insulation of the battery to controller wires to see if there was voltage there, using a voltmeter. That would determine the battery is bad internally or the battery connector is bad. However, doing that would void the warrenty. It is up to you how much your warrenty is worth. I determined I had two trash batteries by doing something like that, and got my money back from Amazon on one of them. You've only got 31 days to get your money back from a lot of these companies.
If you have alligator clip leads and a 15 ohm 250 W resistor, he can remove the battery, connect the two in series and the voltmeter in parallel, to see if voltage at the battery collapses under a 3 amp (48 v battery) load. My trash battery did, but it took me more than 31 days to assemble the test jig, and I did not get my money back from Sun-ebike Baldwin City CA warehouse. Just doing this test may void a warrenty if the phone contact didn't think of it. You can't ship the battery back for testing, you are not a certified haz mat shipper.
If you live near California, Florida, Las Vegas, or Ohio, there are battery repair shops. These may be able to address a bad weld, but probably will want to empty the case and install new cells for a fixed price. You have to drive a LiIon battery to a repair shop; it can only be shipped by certified hazmat shippers.
Next time, the major brands with dealers and short lists of known problems are Trek, Pedego, Cannondale, Gazelle. Giant Specialized & Rad are huge but have a lot of problems posted in the brand threads.

 

[Dyanne78]

Thank you so much for responding. We are in Michigan so Ohio can work. This is still under warranty but the rate the Support team answers (1 email a day with very off-target answers) it may be out by the time they give any real guidance. So frustrating. Pushing them on social media now..I hate that they won’t talk to you on the phone!

 

[harryS]

They use the same battery? Then you could always swap batteries, but you've already verified the Maxfoot MF-18 has power. By the way, a fully charged 48V lithium battery is 54.6V, and can go as low as 40-42V before the bike shuts it off. So 48V is only 50% charged.

If you do swap batteries, verify they have the positive and negative on the same pins. It would be crazy if they weren't the same, but when you switch between different bikes with similar battery cases, sometimes they flip the terminals.

These displays, and your husband will understand, have 5 wires: Battery, Start, TxD, RXd and ground. All they need to turn on is Battery and ground. If they're not turning on, power is not getting down the cable, When they do turn on, the Start wire is powered to the battery voltage. RXd and TXd are serial data lines that start working after the Start signal wakes up the controller. The little three button attachment for the display has three switches in it. That could have failed. The display should start even if the battery is down to 40V, but it will indicate undervoltage. Somewhere lower than that, I dunno, it won't start,

Sometimes, the display has a connector going into a handlebar harness. If both bikes use common displays, at the risk of blowing up a working Trike, one could swap displays,

Anyway, you might want to look for that connector, FIrst ebike we bought, they brought one out of the warehouse and handed it to me, No power, I heard the tech get on the phone with the importer, They told him to plug/unplug the display. I was dubious, but it worked.

 

[Mike TowpathTraveler]

Thank you so much for responding. We are in Michigan so Ohio can work. This is still under warranty but the rate the Support team answers (1 email a day with very off-target answers) it may be out by the time they give any real guidance. So frustrating. Pushing them on social media now..I hate that they won’t talk to you on the phone!

Dyanne, HarryS here is well versed in these bikes and has been a great help to many folks on this forum....

Let me tell you, if you find they won't talk on the phone to you, then you won't be surprised that the guy assembling the bike in the below factory authorized video never says one single word during his assembly of the bike. I've never seen anything as bizarre as this assembly video. In the end, this bike is still under their warranty and things don't work out, hold them to it. Good luck and let us know what you find.

Taken from their same site as the "assembly" video, the owners manual. It has a diagram showing what the various wiring plugs are for: https://cdn.shopify.com/s/files/1/0...17P_and_MF-18P_Owners_Manual.pdf?v=1594096246

 

[harryS]

Nice find on the shop manual. Check the main 4:1 harness at both ends. especially the display connector. They are water tight, and really hard to push in and pull apart,

 

[Dyanne78]

Awesome info Harry & Mike! I will share this with him tomorrow and let you know how it works out!

 

[Dyanne78]

Update: We checked the pack...there is correct power at the main power line coming out of the power pack. The power pack is good and the main power connector from the power pack is good. All checked out. Waiting to see where we go from here.

 

[harryS]

DId you look at the bike manual linked above? THey have a pretty good manual. Make sure the plug for the display is tight, DItto the main at the other end of the harness.

You can also check the #1 connection for 48V. It willl be there on two of the five pins,

 

[zzRider]

If you live near California, Florida, Las Vegas, or Ohio, there are battery repair shops.

Her post said they were in Michigan.

 

[Dyanne78]

Hubby is going out today to go over everything again and will check over all the instructions and diagrams again. Maxfoot is asking for him to send the controller to them and they will look at it. More delays I’m afraid. Fingers crossed something presents itself today. It’s weird that he was able to ride it briefly and then it just failed, the display won’t even come up.