psychonurse

Hi, I am desperate and frustrated!. I purchased a 48V20a.h. LifeP04 battery off one of the members of Endlesssphere.com another electric bike forum. He purchase the battery new from a vendor in China. He decided not to build the bike and sold the battery. When I got home I noticed the charger was for a 36v not a 48v. I removed my old lead acid battery and mounted the LifeP04. It worked fantastic. I received a new 48v charger from PING. I plugged in the charger It was red for a couple of hours then went "green" indication all done. I put it back on the bike and can't get any power. The throttle indicates fully charged. I put back the SLA battery any motor spun normal. I measured the voltage on both the charging port and discharge port and it read 53.4 Volts. I'm at loss as to what to do next. Any help appreciated. Thanks in advance. Mike 818-653-1266

FMB42

First, I'm going to assume that your system controller is setup for a 48 volt 48V LifeP04 battery. If not, then this could be all, or part of your problem (the controller may, as a safety precaution, be shutting the "system down" due to either excessive or insufficient voltage of your 48V LifeP04 battery).

Meanwhile, a "fresh off the charger" 48V LifeP04 battery voltage reading of 53.4v sounds pretty low. Most 48v LifePo4s are fully charged to somewhere between 58 and 59 volts (depending on cell count). This voltage will usually drop to around 56-57 or so after you let it sit for a few hours.

Anyway, I'd definitely contact the LifeP04 battery seller about the apparent battery charger voltage miss-match (note: some chargers have a small switch that allows you to select between 36 and 48 volts).

psychonurse

I will call the Ampedbike company to see if the controller has a "cuttoff safety feature". If so why didn't it shut off before? I was using it on the bike without issue for the past week. Even if the voltage is lower than expected would it not still make the motor run somewhat? If it has a bad cell is the battery toast? Thanks Mike.

FMB42

Be sure to ask Amped Bikes if your particular controller is capable of working with a 48v LifePo4 battery. Most controllers will only work with one particular voltage (i.e. 36v or 48v). However, some of the latest controllers are capable of sensing and then automatically switching over between 36v and 48v (there is no physical switch).


A: The LifePo4 battery voltage "as delivered" may have been low enough to operate within your controller's parameters. But that's just a guess on my part. Btw, did you successfully charge and then use the LifePo4 battery for the past week? And if so, did you do this more than once (i.e. did you "cycle" the battery more than once)? If this is correct, then I'd suspect a loose or bad connection and/or wire between the LifePo4 battery and the system (I say this because your lead acid pack seems to work fine). Also make sure that the LifePo4 battery fuse (if applicable) hasn't blown.

B: Or, did you just ride the bike until the battery was drawn down? If this is the case, then your controller may have allowed you to discharge the battery below the minimum discharge rate (possible due to running a controller that isn't 48v LifePo4 compatible).


No, not necessarily. If the voltage is outside of what the controller expects to see, then the system will not operate (the "level of battery charge" indicator lights will, however, often still work tho).

A "dead cell" could be the problem. But a bad and/or voltage miss-labeled charger could also cause issues (i.e. a 36v charger that has been erroneously labeled as being 48v). But I'd start with the "easy" stuff first (i.e. bad connections, blown fuses, damaged wires, etc).

Hang in there, you'll figure this thing out...