A123 lipo battery range in chinese scooter?

[dutchlincoln]

Hello,
From a friend of mine, i boucht one 48V/40Ah pach with bms and 10A charger. He gets them from a supplyer in china.

Now, i put such a pack in mu wife's scooter.
Today we drove a while. It was cold (8 deg. Celcius), windy, a bit wet, and light was on.
It is a typical chinese electric scooter with 1500 watts motor, going approx. 30Mph tops.
The range it has, from fully loaded to empty, is 30 miles.
Now, in my opinion, that's not much for a 40Ah package?
I don't have any real hard data of WH used or anything.
Is there anything to say off this range, is it right, or is it not enough, or... ?
Not sure how wind and temp. come into play with these cells.

The voltage when empty was 43 volts, wich is 2.7V/cel. (16S)
In my opinion, this is quite low, but the BMS doesn't disconnect them, so...?

What is the max (full) and min. (empty) voltage of these cells?
Charger says 60.5 volts...

Thanks!

 

[dnmun]

the BMS will shut off if the lowest cell reaches the 2.1V mark. you should buy a turnigy wattmeter or cycle analyst to monitor discharge. make sure to charge it all the time until the pack balances if it is new. should reach the 60V and have all the cells above 3.65V.

 

[SamTexas]

That's about 70Wh/mi at 30mph top, or 2,100W average power.

Too high an energy consumption rate for that speed. So either the pack was not fully charged or the capacity is much lower than 40Ah, or both.

Edit to add: Or the BMS (if there is one) is misbehaving.

 

[999zip999]

I would not go around triing to find the bottom of my pack. As you don;t run your gas tank to empty just to fill it up. Try breaking in the battery in for one week or more and leave on the charger for a while to balance.
Is this on flat land or hills ? Stop and go ? ect.

 

[dogman dan]

The cold alone could easily be costing you 5 ah of capacity. Then if the pack is unbalanced, you'd lose another 5 or so. If both are the case, then your range would be about right for 30 ah, at that speed.

First off, put the thing on the charger, and get it fully charged. If it has a bms, the bms could take up to weeks to balance the pack if it truly is that severely out of balance. If it is so, you will be seeing the charger turn back on for breif perionds from time to time.

Ride it shorter rides for now, and charge it a lot. It should improve some as the battery regains it's balance.

Another thing, how you ride it makes all the difference. Lots of stop signs can cost you 20% of your range for example. Lowering your speed by 5 mph could gain you 20% or more. A heavier bike will also cost more watts to climb a hill.

It should be quite possible to get 50 mile range from that battery or more, but not by jackrabbit starts from lights to 30 mph, followed by a relatively soon stop again.