Anybody have manual for Vpower 48V 5-amp LiFePO4 charger?

[Little-Acorn]

I got a 48V 20Ah LiFePO4 battery from a chinese company on Ebay, and it came with a Vpower 5-amp 48V charger for LiFePO4. Does anyone have a manual or instruction sheet for this charger?

I think the battery had a fairly full charge when it arrrived, it drove my ebike at fairly good speed with no apparent sagging. I put the battery on the charger, and the two LEDs came on. One was red and stayed that way throughout the charging session (which wasn't very long). The other was yellow when it came on, stayed that way for about 10 minutes, then turned green. A few minutes later it turned yellow again, then green, changing color every minute or two. I disconnected everything after 30 minutes or so, not wantinng to overcharge the battery before I knew what the charger was trying to tell me. The first LED stayed red for the entire 30 minutes, and I don't think the battery ever reached a full charge. Maybe that first LED would have eventually turned green if I let the battery charge all the way up, but I don't know - I'm only guessing about that part.

Does anyone know what these LEDs mean?

 

[icecube57]

You really need to invest in a volt meter. That would help us alot in figure out whats going on.

 

[dogman dan]

Very likely the battery is balancing when it does the green yellow cycles. New batteries take a few cycles to break in, after which they should stay balanced enough for you to seldom see the bms working. Your vendor should be able to answer what the led's mean exactly.

 

[Little-Acorn]

I have a Fluke DMM and a WattsUp meter, haven't installed the WattsUp yet.

I plugged in the charger to the battery and into 110VAC, and it began the same behavior as described above. This was after it pushed my ebike (48V 1000W) for maybe ten minutes up and down the neighborhood, so I expected the charge to be a little depleted.

I left it for an hour, then came back. The LED that had always been red before, was still red. The one that had cycled between yellow and green, was yellow. Don't know if it was about to change back to green or not. I measured the voltage where the charger connected to the BMS, and got 60.2 VDC.

Then unplugged the charger from the wall, and disconnected it from the battery (BMS). Then measured the voltage at the BMS terminals again, and now it said 57.8 VDC (no current flowing now, or so I assume).

Does this seem fairly reasonable for a battery which just got charged up to the "full" point?

I hope to install the WattsUp meter on the handlebars in the next few days. Don't especially like the idea of running the high-amp wires (I have some 12ga wire) from the battery/BMS on the back rack, all the way up to the handlebars, then all the way back to the controller just behind the seat. But what's a mother to do. I want to be able to monitor amperage, voltage, amp-hours used, etc. as I ride, and that's the only way I can think to do it, unless I start fiddling with battery and/or controller placement.

Sound like a plan?

 

[amberwolf]

The only way to avoid running such long power wires (without moving your pack or your controller) is to use a meter with an external shunt (like the CycleAnalyst), or modify your WU by moving it's shunt to an external mount, with shielded (and/or twisted-pair) wiring.

 

[dogman dan]

Yup, at full charge, it should be close to the 60v hot off the charger, and then drop a few volts when the surface charge dissapates, or you run the wheel for 2 seconds. You are nearly fully charged, but not quite, I think.