it looks like my xl-4000li battery is dying
Just got my xm-4000li (used). The bike has been in storage for months. It was shipped to me from New York. First I got the DC-DC converter problem. That seems to be fixed now, See: DC-DC converter . Last night I charged up the moped to full. This morning I rode it to work, it is only 5 miles. During the trip the battery gauge dip down to the red zone at some hilly roads (about 10 - 15 degree and I only weight 135-lbs). When the needle was at the red zone the red LED was blinking. When I got out of the hilly road, the needle was not quite at the red zone but fairly close. When I got to work, the kickstand was down, the needle of the battery gauge indicated that I had use up about 30% of the capacity from full level. I plugged the charger to a 110v circuit, it took about 1hr to charge it back up to 100%. I have the following questions,
1. How bad of a shape you think my battery is?
2. The red LED on the dash board is on solid the whole time when I turn the moped on, is it normal?
3. Occasionally when I ride above 40 mils/hr or climbing a hill, the needle drop down to the red zone. Is it okay to ride light that?
1. Your battery is in bad shape. The only time my 4000li ever dipped into the red zone (with LED flashing) was when the charge was extremely low. It is also termperature dependent, and you didn't mention what the ambient air temp. On full charge, healthy cells, and warm weather of 90F, my 4000li barely dips below 3/4 even on hard acceleration. Now I am at 13,250 miles, and still within battery warranty, so I plan on checking my cells soon and replacing any that are low.
2. LED should always be on. Just not flashing.
3. I think regardless of what you do, you will be replacing the cells soon. It sounds like they sat too long without being cycled and charged. And a 5 mile trip, and 40 mph should be nothing for a 4000li. I have been able to maintain 50mph and 40+ mile trips with no problem when the cells are healthy.
Mine sat for awhile too as a showroom display prior to me purchasing it with 14 miles on it for $1900. Fortunately I have the full 2 yr warranty on the batteries and will be sending them in for warranty check and replacment in a couple of months.
Your battery pack is heavily unbalanced and probably some cells are dead. If you don't want to damage and kill even more cells, do not charge the pack and do not ride! Every charge cycle will damage the pack more and more.
You need to individually measure voltage of every cell. Each cell should read at least 2V. If some of the cells will read 0V, it needs to be replaced. If reads below 2V it still may be OK or may have reduced capacity.
Then individually charge each cell to 3.6V. You can get special one cell charger for that (like: http://www.ev-power.eu/Chargers-Single-Cell-4V/Charger-3-6V-6A-for-LiFePO4-cells-1-cell.html ) or an universal lifepo4 charger used by RC guys like Turnigy ECOSIX etc..
Then you are ready to ride again. But I still heavily reccomend you to get a balancing BMS to keep your pack safe and healthy.
You may try with 20cell of CHL 40AH battery come with BMS,Usd1450 include freight !
Sorry,wrong photos,that's for ZAPINO
see attached XM4000li with CHL battery
When battery is full,no accurate to find out the difference.
Only check voltage when battery is low,this way you will easily find out defect cells
ezquimin, no need to take cells out nor disconnect them for measuring their voltage individually. About how low to go I'd be careful, going too low is one of the deadly things you can do to your LiFePO4 cells...
Bottoming out is never a good idea, unless you are attempting to end the battery life now. I have a digital voltmeter on my dash, and I have never run as low as 57.8v under load. The lowest I have ever seen is around 59, and I kept that brief. At 3913 miles, my cells at low charge were identical at 3.28 v. (yes all 20) In perfect balance. Also at 3913 miles, full charge of 79 volts, my lowest cell was 3.52 and my highest cell was 4.07. In my opinion, your cells are way off. Your 4000li sat too long without being charge.
I am at 13,250 miles now, and my full charge voltage reads around 75 now. I am going to check all cells for warranty soon. But 13,250 completely trouble free miles with no BMS....I wouldn't even accept BMS if someone tried to give it to me.
You don't need to connect it directly to the controller.
What you need is to buy the high current model with an external shunt of 0,5mOhm.
It's quite easy to connect, just connect the shunt somewhere between the battery and controller on the negative side, 2 wires from the CA to the shunt and 1 to pack positive.
For the speedometer you could use either the "magnet solution" wich is the simplest, or connect it to the hall sensors from the motor, which is a little bit more complicated.
Thanks Johnny, I just look at the cost. It is almost $200 with shipping and all. That is a little pricey for me. All I really need is a reliable way to measure the battery charge (or a good fuel gauge). I am looking around for a low end watt meter or Ah meter but all of them only handle up to 60v. I wonder if any one find a way to measure the Ah usage of these scooter while riding on it without have to pay more than $100? Thanks.
It's around $160 with shunt and shipping and I would say it's worth every penny. :-)