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![]() If anyone happens to know anything about this BMS, I’d love more information. There’s not much in terms of labeling either. It’s a “Hitech 10S_100909” - I can’t find a thing about that BMS, so I’m treating it as a black box, sadly. The cells are 18650s, which is great - they’re a standard size and easy to obtain. As this is a battery pack, that’s a good thing. The first view we get with the shell off is the BMS (Battery Management System), some padding tape and a whole lot of batteries. Two bolts and a bunch of snaps hold the shell together. It doesn’t matter anyway as it’s a 4 year old bike. Warranty is void in the event proper care instructions as per the owner’s manual are not followed.” _One year warranty? This is why I like LiFePO4… Also, I’m reasonably confident fully draining the pack is not proper care. According to the information that came with the bike, the warranty for the battery is _“Lithium-ion type: One year (12 months) from purchase date by original owner. Please contact a qualified dealer for service. “For safety and function reasons, user’s disassembly is not allowed. Fortunately, the sticker is still there - just sliced! I should note here that the previous owner did pop the pack open when it died, so I’m not the first to be in here. I’m not entirely sure yet what the blue wire is, but I believe based on some conversations with iZip that it’s a voltage sense wire (it just happens to be a lot larger than needed).Ī close inspection of the end of the pack indicates that I’m going to void the warranty if I remove the sticker. The black and red wires on the “triangle” plug are power and ground. The other (thinner wires) connects via a cable to the external charging port up higher on the tube. One (the triangular connector with thicker wires) goes to the motor controller. There are two three-pin connectors coming off the pack to disconnect before removing it. It’s surprisingly easy to remove, though - remove a few screws, the bottom of the tube (containing the controller) drops out, and the pack follows quickly. The pack lives in the thick frame tube, arching up from the pedals to the steering bearings. iZip had nothing to do with this teardown and isn’t responsible for any of the stuff I did to their pack. This teardown was done against the best advice of warning stickers, totally voiding any remaining warranty on the pack (not that there was one 4 years later), and is definitely not a good idea. So, of course, I tried to.Ĭontinue for lots of interesting teardown pictures… A bit of research indicates that I can do a lot better. Neither is 2.7v or greater…Ī replacement OEM pack is $600. ![]() Individual cells were between about 0.6v and 1.2v. That’s “bad.” That voltage, combined with the time sitting, means the pack is physically damaged, recharging the batteries is not a good idea, and even if it will take a charge, it’s very likely significantly short on capacity. ![]() Maybe down to 27v, briefly.ġ0 volts for the whole pack is right out. That means the pack should live between 30v and 43v. Skipping to the punch line, this is a 10S pack. They must exist in a voltage range between about 2.7 and 4.3 volts per cell (and spend most of their life in the upper 3v region).ĭischarging a lithium cell below 2.7 volts tends to do physical damage to the cell if it’s left there (and, really, you shouldn’t ever have them below 3v/cell for any length of time). Lithium cells are great in terms of power density and energy density, but they require some specialized care and feeding. The bike uses lithium cells - ICR ( LiCoO2) cells to be specific. I got a back story involving the charger, a power outage, and the pack dying, so perhaps the charger drained it after the power outage, but whatever the case, it was dead. Unfortunately, this one wasn’t going to do any assisting at all. Of note are the very small, high pressure tires - it’s supposedly quite efficient as far as power use goes, even on a higher assist setting. This is a 500W geared rear hub motor, pedal assist ebike, with a 36v, 10AH pack. Please ignore the stack of phones and tablets on my desk that I need to fix or strip for parts…Ī quick trip to pick it up, and I had the following sitting in my garage: One of my flaws is that I’m a sucker for free stuff I’m interested in, especially if it originally sold for a lot of money. Someone at work was getting rid of an ebike they were sick of.
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