Replacement Battery choices for the e-trike

[Deleted member 4366]

That's a start, but still no info on the controller or motor. IIRC, there was some sort of large DD motor on those trikes, so I guess a minimum 500w, for which I'd expect a controller of at least 22 amps. those batteries are rated at 10 amps, and they're OK up to about 15 amps (without knowing what cells are in them, but assume cheapo LMNC because they didn't mention a cell type), as long as you don't go that high for too long, so IMHO, they're a little under-rated, stress could be high, especially with a DD motor, and life would be shortened. These of course are all assumptions and guesses. If correct, it doesn't mean that the battery is no good. You have to weigh up all factors like cost, appearance, performance, weight and life. Choose the best balance that suits your application. If it were my trike, I'd have gone for a battery with a higher discharge rate because you get less sag, which means more power and longer range from the same number of aH, and less problems in the future.

 

[twinkle]

Dave

I think the motor / controller package is a " DD golden pie at 500w " Sorry no data on it , The controller appears to have some degree of regeneration as the external battery indication can reach 6 bars if cycling at speed without power .
Don't know any more . It was a non repeatable good deal I got for the pair during the middle of last year when I started to play with e-bikes and started to build trikes .

Its been in use now since August last year and between them have covered over 1000 miles usually about 50- 80 a week and that should increase as the weather improves .

regards emma

 

[Deleted member 4366]

Regen can also bring problems if the battery cells and BMS are not designed for it. You should email the supplier, and ask him about it. One thing that I can think of is that the charge current should be about 2,5 amps, or maybe 5 amps absolute max (2.0 +/- 0.5A in the spec.). Regen can go much higher than that down a steep hill. Is your regen adjustable in any way? You might even find that the BMS doesn't support regen, so it might not be working any more.

 

[twinkle]

Ho Ho ******* ho wheel / controller ,supplier was a box pusher with a less than zero IQ regarding all forms of e-bike kits , I have as much chance as making drinkable tea in a chocolate teapot as getting any information on the controller . Only reason for the statement about regen is that the external voltmeter I fitted within the viewing path can be illuminated by furious pedalling with the ignition switch in the off position . Only way I can prove either way is to fit a 30-030 ammeter in series with the battery feed and run it down a long hill to prove .
The battery spec says 25amp continuous rating and I cannot see the output rating being as low as 15amp , The first battery has been in use for 6 weeks now since replacing the SLA batteries without a problem , and I have not noticed a sag yet whilst in use or a rise in temperature of the battery pack whilst in use , only time will tell.

Its easier to say I told you so after the event unfortunately it a case of use what is to hand ,
The original project was to make a low cost functional piece of unusual transport ( the e-trike ) FROM SCRATCH to use as everyday green transport and to keep fit rather than use the car . .
The results proves the point that it can be done .

During the next week or so I will have a play to see IF there is any regen current of any real value being fed back towards the batteries ..

 

[Deleted member 4366]

I think it means that it has a 25 amp BMS, not that the cells can give that much. Do you have battery indicator LEDs that show what's happening under power?

 

[twinkle]

Hi Dave

Only a 3 led indication on the red trike and a battery check lamp on the battery
obviously unless you are a 2" high dwarf or a contortionist it would not be possible to monitor either.
I will need to attach a DVM to get a clearer picture of what is going on again something to look at , nearer the end of the week . It should not be difficult putting a voltmeter and ammeter into the connections .rather than using my RC power meter that wont give me any regen current indication

We use a lot of Lipos in the model aircraft we fly and obviously not the same technology ( lipos are more unstable ) we are draining well over 40 amps OFT from 3s1p lipos 1800 mah and these survive quite happily with only a low voltage cutout built into a "basic controller"

Even my reserve battery a 13s 1p 1800 mah lipo multipack is good for over 3 reserve miles without getting warm.

This new battery pack says it is suitable for up to 800 watt motors and thus these should at a nominal 800 watts .will be drawing 17AMPS
obviously that is a mean and not PEAK current .
so at under 500 watts a nominal 10 Amps drain is considerably less

 

[twinkle]

this is the controller a typical "noname 48v controller "

 

[twinkle]

Further investigation shows that it is not a "regen" controller . I think there is a little of the generative feedback of the direct drive brushless motor being rectified by the output transistors on the " overrun " this does not occur unless you can "spin" the wheel at "road "speeds greater than 25 mph ( 140 rpm cadence on a 86" gear) and the generated( leakage ) current is only a few milliamps .The battery voltage seem stable and whilst out on a 12 mile ride today the voltage indicator did not drop below the middle led ( of 3) OFT

regards
emma.