Advice on repairing my ebike

rbrouwer

New Member
Region
USA
Hi,
I am 63 years old and in 2020 I bought a inexpensive Ecotric 27 Hammer for myself and the matching smalling folding Ecotric bike for my wife. My Hammer some how fell off my bike rake on the highway and not get run over. The bike is rideable, on/off/shifter button cover went missing, the gear shifter got damaged and does shift gears, I can turn the bike on but it will not stay working. When I put the Hammer battery in my wifes bike it will do the same thing and turn on but quickly turns off and not work. It seems like the battery is damaged. My wifes battery will not fit in my hammer, so I can verify that the Hammer battery is damaged.
Any advice on repairing my bike or should I just replace?
 

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Since you are not familiar with electric bike or bicycle innards and components, you should replace it.

I build my bikes from the frame up so I could deal with something like this, but it would be a long process of diagnosis that could probably get really ugly in terms of figuring out which electrical components are damaged, if the problem is not obvious. You could end up replacing one part after another starting at the display, working down to the wiring harness and the brake cutoffs, then to and thru the controller and so on.

Then there is the cost of diagnosing and replacing the bicycle parts. While the bike was bouncing around, did the crown race get dented on the headset? Thats not immediately obvious but will be as soon as you take a test ride. Will you know what it is you are feeling thru the bars when you feel it?

If you love a long term project, thats the only way you're going to get any measure of success out of this after a lot of trial, error and research (unless you get lucky... it could be an easy fix but you won't know until you succeed how much time, effort and money it will take). Write it off and buy another bike.
 
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Those are commonly available silverfish batteries, so you could consider a new one for the Hammer.

These are both 48V batteries right? If your folder is 36V and the Hammer is 48V, you can't swap batteries and use that as a test. But say they're both the same. I don't see why the folder battery won't fit into the Hammer, unless it's too short for the key to turn in the locking plate. Remove that plate temporarily, Then if the Hammer powers up with the other battery, then you'll feel more confident about buying a new battery. But make sure the bike still works frist and has no cracks on the frame. Hate to see it split in half on you. A new Hammer isn't much money and you might want to try a different bike anyway,

Used to own an Ecotric 20" folder. That's why I know how the battery goes in.

From the pictures, it seems the battery powers up, shows full charge on screen, but shuts off when you run the bike? Something broken inside. Based on what your tool bench looks like, you'll probably be looking in there. Be careful if you do. Go ask the guys at endless sphere if you want to investigate it.
 
Those are commonly available silverfish batteries, so you could consider a new one for the Hammer.

These are both 48V batteries right? If your folder is 36V and the Hammer is 48V, you can't swap batteries and use that as a test. But say they're both the same. I don't see why the folder battery won't fit into the Hammer, unless it's too short for the key to turn in the locking plate. Remove that plate temporarily, Then if the Hammer powers up with the other battery, then you'll feel more confident about buying a new battery. But make sure the bike still works frist and has no cracks on the frame. Hate to see it split in half on you. A new Hammer isn't much money and you might want to try a different bike anyway,

Used to own an Ecotric 20" folder. That's why I know how the battery goes in.

From the pictures, it seems the battery powers up, shows full charge on screen, but shuts off when you run the bike? Something broken inside. Based on what your tool bench looks like, you'll probably be looking in there. Be careful if you do. Go ask the guys at endless sphere if you want to investigate it.
 
Thanks for your great advice about removing the battery rail to test with my wifes bikes smaller battery. It worked great, so now I am wondering how you would recomend repairing or replacing the battery.
 
I carefully disassembled the baterry and attached pictures if this would help. I do have some electronic experience with building my own Heathkit stereo system a long time ago.
 

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I am not trying to be a jerk here so don't take it that way. What you are doing and describing with your level of experience is almost the textbook example of how a battery fire happens.

Just for starters, if you have a short and that battery is sitting on that carpet, thats a fuel source. If doing something like this whether you know what you are doing or not, you want top do it on concrete and, if possible, in a large area with no roof structure that can burn.

And you want a big fire extinguisher on hand rated for lithium ion fires. I have a buddy who owns an ebike shop and he showed pics privately of his (very large) repair shop where a pack caught fire, and the whole shop was blanketed in powder. But it didn't burn down because he hit it hard and fast with the right tool for the job.

Believe it or not, water is actually VERY good for one of these types of fires. If caught early, low-intensity water will keep the pack temperature down so it will not put out the cells on fire, but it will prevent thermal runaway of the adjacent cells while the burning ones burn out. But you have to stand pretty much over it for a good half hour so indoors is not the place where that is going to happen.

Your battery pack is divided up into groups of probably 13 cells each (in series). Maybe 4 of those connected together in parallel. Each of those groups is welded together on the ends using a special spot welder, and impacts often damage/break those welds. Additionally each of the parallel groups has a wire coming from it to the battery management system. You can pretty much see none of that with how far you have disassembled the pack thus far.

Like I said originally, you will have to have significantly greater understanding of what you are looking at before you can be anything but dangerous. So either set this aside and start learning the ropes of battery construction (Endless Sphere is where you want to go for that) or just go buy a replacement battery with the same plugs for charging and discharging that you have now.
 
Yes, I remember Heathkits and tube amplifiers, I built a Knight kit amp, but only one channel, No stereo.

Neither Robertson or I want to see you get in trouble. so I don't endorse tearing into the battery, but I would like to know what happened. You said the bike powered up. What caused it to power down? Did you try to run the motor? Were you able to turn it back on with the middle start button on the SW900?
 
Thanks for your great advice about removing the battery rail to test with my wifes bikes smaller battery. It worked great, so now I am wondering how you would recomend repairing or replacing the battery.
I found this Ecotric Hammer replacement battery on Ebay. Is there a cheaper option some place else? Is it worth investing into this bike? Remember, I do have the matching Ecotric folding bike that could I believe I can also use this bigger battery if needed. What would you do? Thanks for all your advice!
 
Yes, I remember Heathkits and tube amplifiers, I built a Knight kit amp, but only one channel, No stereo.

Neither Robertson or I want to see you get in trouble. so I don't endorse tearing into the battery, but I would like to know what happened. You said the bike powered up. What caused it to power down? Did you try to run the motor? Were you able to turn it back on with the middle start button on the SW900?
I appreciate both of your concern!
So when I try using to hammer battery in the hammer and also my wife's folding bike it powers on briefly and the throttle will power the tire but then the screen goes blank. My wife's battery works both bikes normally.
 
Sounds like you've isolated the trouble to the battery. The battery listing you have shared does not list which cells are being used in the pack. Only "Grade A high power cells" is extremely vague. Are they Panasonic, Sony, Tesla, Molicel, Sanyo, Samsung, LG? Those are the only branded cells I would look at. There is also no BMS info listed. You can ask the seller, but they may not be willing to disclose that information. It seems the cheaper the battery, the less info the seller provides. Also, a cheap battery is most likely not built to the highest of quality standards. Sure the battery could work well for weeks or months, but with "Grade A high power cells" they may not be matched before pack assembly and would degrade faster than higher quality cells. A pack built with unmatched cells would most likely end up having a bad cell group. You may find yourself looking for another battery pack before a year has passed. Seeking a pack built with name brand cells could avoid some of the mystery. When choosing a battery, look at quality first. Since the battery is the most expinsive part of the bike, you want to be sure it's a quality pack with quality cells. This way you can have a pack that will function the way you hoped it would.

If I were in your situation, I would check out the Ecrotic brand forum and see if anyone else has purchased a battery for the Hammer and see what battery others have used. Or even look at bikes that use the same battery and see what replacement batteries those users have purchased. My first choice would be the manufacturer, but that may not be an option if the battery style has been discontinued. Some users here have gone to @Jenny Mao , but there may be other reputable sites that I am not familiar with. Normally, you'd want to purchase your battery from a seller willing to disclose the battery cell information.
 
Sounds like you've isolated the trouble to the battery. The battery listing you have shared does not list which cells are being used in the pack. Only "Grade A high power cells" is extremely vague. Are they Panasonic, Sony, Tesla, Molicel, Sanyo, Samsung, LG? Those are the only branded cells I would look at. There is also no BMS info listed. You can ask the seller, but they may not be willing to disclose that information. It seems the cheaper the battery, the less info the seller provides. Also, a cheap battery is most likely not built to the highest of quality standards. Sure the battery could work well for weeks or months, but with "Grade A high power cells" they may not be matched before pack assembly and would degrade faster than higher quality cells. A pack built with unmatched cells would most likely end up having a bad cell group. You may find yourself looking for another battery pack before a year has passed. Seeking a pack built with name brand cells could avoid some of the mystery. When choosing a battery, look at quality first. Since the battery is the most expinsive part of the bike, you want to be sure it's a quality pack with quality cells. This way you can have a pack that will function the way you hoped it would.

If I were in your situation, I would check out the Ecrotic brand forum and see if anyone else has purchased a battery for the Hammer and see what battery others have used. Or even look at bikes that use the same battery and see what replacement batteries those users have purchased. My first choice would be the manufacturer, but that may not be an option if the battery style has been discontinued. Some users here have gone to @Jenny Mao , but there may be other reputable sites that I am not familiar with. Normally, you'd want to purchase your battery from a seller willing to disclose the battery cell information.
Jenny has has some issues such as over output chargers. Danger. Whenever my dyslexic brain sees Ecotirc it sees Erotic. These $900 bikes are anything but erotic. I have my eye on a Como SL, super light, with a Gates drive belt and sealed internal gears where no solid parts have direct contact, from a mid-drive with a silent internal belt. Now that is a beautiful bike that is intuitive and smooth. The Ecotric will cost more than the Como SL over three-years, and it will still be a total dud 100% of the time. Don't go there. Cheap razor blades are more expensive, especially on your face.
 
Most bikes use the 5.5x2.1mm barrel plug which is rated for 5a. As long as the charger is less current than that, you should be good.

I have a 2a and a 3a charger for my battery. The 2a charges at 1.5a max and the 3a charges at 2a max. I’m starting to think that the current of the charger is the max output. The CC may not peak at the chargers rating.

I keep reading “Erotic” as well. Each time I see it. Maybe that’s what the company is going for. I mean, you won’t forget the name. And now look at us, talking about their brand. Lol
 
I replaced the 36V Silverfish battery in my Ecotric with a UPP brand off amazon. Everyone hates UPP because their triangle frame batteries are banned in US and UK, but their standard case batteries are made as well as any other maker, and are available with Samsung cells at extra cost, I;ve owned five UPP batteries since 2016 with no failures, while the Ecotric only lasted two years, However, you can only buy UPP Silverfish packs from their CHina website,

I bought the Ecotric fat tire folder in 2019, and discussed it in the Ecotric forum. Basically a well made bike for its price (I paid $700). They were offering UL rated batteries in 2020, Cheap steel rims and a 3 speed controller were its main tradeoffs, If it had been their lighter weight skinny tire folder, I might still own it,

Anyway, the Silverfish (what an awful name ,,, makes you want to stomp on it) battery is an old design, probably better than all the plastic ones in my opinion, but not good for sleek new ebike designs,
 
I was just watching this video and the speaker, Justin from Grin Technologies, responded to a question about putting out battery fires that is I think the best, most succinct way to answer that question and tell people why the standard internet answer (do not use water) is absolutely wrong, as well as a real world description of what happens with a chemical fire extinguisher.

This is a 42 minute presentation I have queue'd up to the moment where the question is asked and answered:

 
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