stocks17 Posted November 3, 2023 Report Share Posted November 3, 2023 Hey there, Wow it's been a long time since I've been on this forum, I think I had a Montesa 315 last I posted here. I now have an older EM sport. I think it's like a 2015, just noticed lately when the battery is charging it'll get to the last two bars and start blinking. If I shut the battery off and turn it back on it'll show a full charge. Just curious what this indicates if anyone's a battery expert. Thanks Quote Link to comment Share on other sites More sharing options...
konrad Posted November 3, 2023 Report Share Posted November 3, 2023 That's strange behavior. The LED display is an autonomous voltmeter that is not being controlled by the BMS. There are two relevant pages on my EM website. This one describes the 5.7's battery in some detail: https://www.electricmotiontech.com/home/em-5-7/5-7-battery This one shows two inexpensive power meters (one for the DC side, and one for the AC side of the charger) that have helped me understand the charger's progress: https://www.electricmotiontech.com/home/em-5-7/10-amp-charger Quote Link to comment Share on other sites More sharing options...
dgshannon Posted November 3, 2023 Report Share Posted November 3, 2023 9 hours ago, stocks17 said: ... just noticed lately when the battery is charging it'll get to the last two bars and start blinking. If I shut the battery off and turn it back on it'll show a full charge. Taken literally, this suggests that you have the battery turned ON while charging. Not sure that is a recommended state, or that the indicator should be trusted while doing do. Quote Link to comment Share on other sites More sharing options...
konrad Posted November 3, 2023 Report Share Posted November 3, 2023 (edited) 14 minutes ago, dgshannon said: Taken literally, this suggests that you have the battery turned ON while charging. Not sure that is a recommended state, or that the indicator should be trusted while doing do. The older EMs (5.7 / sport) require that the battery switch be on during charging. The BMS detects voltage at the charge port and enables the charge relay instead of the discharge relay. Edited November 3, 2023 by konrad Quote Link to comment Share on other sites More sharing options...
BC_Islander Posted Thursday at 09:42 PM Report Share Posted Thursday at 09:42 PM Hi @konrad thanks for your excellent resources in regard to the Epure line of bikes. I am the owner of a 2017 sport recently purchased. My battery does the exact same thing, flashes last bar (nine I believe) on the indicator and then when you shut everything down, shut everything off and then turn it back on. It'll show a full charge reading on the indicator I had no issues with this strange behavior as the previous owner had mentioned it to me. However. i'm now having the BMS kicking out after 15 seconds no matter what the state of charge. Likely according to epure France, because the one of the cells is reading too low in relation to the others and the BMS is shutting it down to protect the overall battery pack. The problem I'm having, is that with Lipo batteries no one will work on them. Before I take the pack out and try and figure out how to send a lithium hazardous material device all the way back to France. Is there anything I could do locally with a multimeter alligator clips and a lightbulb or something to test whether or not it's a bad cell or bad contractor or bad bms or is there a way to renovate that bad cell? Quote Link to comment Share on other sites More sharing options...
konrad Posted Friday at 02:08 AM Report Share Posted Friday at 02:08 AM This is the big problem with electric motorsports. The battery is not something you can work on without specialized knowledge. There is no way to rejuvenate a bad cell. It takes HAZMAT certifications to ship even a small vehicle battery. See: https://www.electricmotiontech.com/home/em-epure-race/battery#h.orhjts73kbs9 It is possible to read the 5.7's BMS. See: https://www.electricmotiontech.com/home/em-5-7/5-7-bms But again, not without specialized knowledge. About the only thing you can do is eliminate the charger as the source of the problem. (A 5.7 owner contacted me saying he thought his battery was bad, but it turned out to be the charger.) 1 Quote Link to comment Share on other sites More sharing options...
BC_Islander Posted Friday at 03:05 AM Report Share Posted Friday at 03:05 AM Thank you. Can you suggest steps to test charger? Battery has rs-232 port so maybe can voltage/amperage be monitored during charging I wonder? I have a fluke dc clamp meter if that helps... Quote Link to comment Share on other sites More sharing options...
ChrisCH Posted Friday at 07:35 AM Report Share Posted Friday at 07:35 AM Depending where you are there are other options to sending the battery pack to the manufacturers. There are here (UK) places that will rebuild battery packs for ebikes and would, I imagine, therefore be able to rebuild an EM pack. If there is a duff cell it could be replaced by that type of service centre. Worth having a search around for places that advertise repairs to ebike batteries. Quote Link to comment Share on other sites More sharing options...
konrad Posted Friday at 11:54 AM Report Share Posted Friday at 11:54 AM 8 hours ago, BC_Islander said: I have a fluke dc clamp meter if that helps... This section is particularly relevant: https://www.electricmotiontech.com/home/ev-tech-101/battery-care-and-feeding#h.qujvukxy97fa (But the entire page will be helpful.) Making measurements is one thing. It's quite another to interpret the results, and I'm not prepared to attempt to teach that. As Chris pointed out, it's best to find someone locally who knows what they are doing. But, as you discovered, the 5.7 uses "pouch" cells and most rebuilders work with cylindrical cells. So the entire pack will have to be replaced if you go that route. Quote Link to comment Share on other sites More sharing options...
ChrisCH Posted Friday at 02:55 PM Report Share Posted Friday at 02:55 PM 2 hours ago, konrad said: ..... As Chris pointed out, it's best to find someone locally who knows what they are doing. But, as you discovered, the 5.7 uses "pouch" cells and most rebuilders work with cylindrical cells. So the entire pack will have to be replaced if you go that route. I did not know they all have to be changed. You can certainly get them: https://ebikebatteries.co.uk/product-category/li-on-lifepo4-cells/li-nmc-pouch-cells/ So much to learn about new technologies after a lifetime of petrol engines. Quote Link to comment Share on other sites More sharing options...
konrad Posted Friday at 05:42 PM Report Share Posted Friday at 05:42 PM Sorry, did not mean to imply that just because they are pouch cells, they must all be replaced together. You can certainly replace a single pouch cell in a battery with an identical pouch cell. It's just that since most battery rebuilders work with cylindrical cells, they would likely only fabricate an entirely new battery from cylindrical cells. Which, depending on the condition of the other pouch cells in the battery, may be prudent anyway. And maybe this is why the OP wants to send everything to France? Quote Link to comment Share on other sites More sharing options...
lemur Posted Friday at 07:01 PM Report Share Posted Friday at 07:01 PM Imagine if you could build something that held all the little round cells in stacks so you could replace just one bad one at a time, sort of like in a 100 year old flashlight. I bet they make them like that some day. 1 Quote Link to comment Share on other sites More sharing options...
ChrisCH Posted Saturday at 09:27 AM Report Share Posted Saturday at 09:27 AM 14 hours ago, lemur said: Imagine if you could build something that held all the little round cells in stacks so you could replace just one bad one at a time, sort of like in a 100 year old flashlight. I bet they make them like that some day. The future - I hope - is lighter and more powerful batteries. Solid state looks as if it is near to a point that it will meet those criteria, just price that remains a problem (well for most of us...) One of the big gripes in the ebike world is the lack of standardisation. Motors vary between bikes and within the same manufacturer. The market needs to shake out and settle on one standard and then produce in volume to get prices down. In a perfect world the battery element of the equation would be just "fuel" and something you can change easily and not at 50% the cost of the complete bike. Quite a few of the people I know that are running or looking at battery cars are leasing as they think the battery technology will change soon. That said the government are keen to do away with the tax relief so I am not sure the volumes are going to be there yet. 1 Quote Link to comment Share on other sites More sharing options...
BC_Islander Posted Sunday at 03:16 AM Report Share Posted Sunday at 03:16 AM This is good to hear! France says they can fix the battery but can they do it without shipping it to them? Doubtful. The remote debug option would be great if I could get someone technical on a zoom call. I have considered having a shop rebuild the battery with 18650 cells but $$$$! Good to hear that if I get really stuck one can VERY CAREFULLY with full PPE (yes I am a retired structural fire fighter) remove and replace one pouch! Now I just need to figure out which one is giving me the grief. Seems like a good application for a fuel cell. https://www.designboom.com/technology/mit-open-source-hydrogen-electric-motorcycle-fuel-cell-ces-2024-01-12-2024/ https://www.kedglobal.com/hydrogen-economy/newsView/ked202303310001 Quote Link to comment Share on other sites More sharing options...
BC_Islander Posted Sunday at 03:23 AM Report Share Posted Sunday at 03:23 AM On 9/27/2024 at 7:55 AM, ChrisCH said: I did not know they all have to be changed. You can certainly get them: https://ebikebatteries.co.uk/product-category/li-on-lifepo4-cells/li-nmc-pouch-cells/ So much to learn about new technologies after a lifetime of petrol engines. Unfortunately Jimmy (owner? founder?) is very sick with cancer and looks like they will be winding down operations. Quote Link to comment Share on other sites More sharing options...
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