Battery compatibility - quick question

DavidfromOhio

New Member
I want to order this battery for the ebike I'm building. It's not brand name but it has good reviews. My motor is 1000w AW kit though. Would this still work? I heard something about it needing to have a certain discharge rate in order to work? Is that true and if so what does that mean? I thought as long as the voltage matched and amp hours are decent that's al that matters. They have one that says 15ah that they say supports 1000w and is about $100 more but weighs the same (10lbs)which is suspicious unless it's a typo.

-EBIKE
5.0 out of 5 stars 4Reviews
SUN-EBIKE 48V 12AH Li-ion Lithium Battery Aluminum Case Fish BMS 3A Charger Rechargeable use for 250w 350w 500w ebike Motorcycle

  1. SUN-EBIKE 48V 12AH Li-ion Lithium Battery Aluminum Case Fish BMS 3A Charger Rechargeable use for 250w 350w 500w ebike Motorcycle

 
From the specs:
Maximum continuous discharge current: 15A
Maximum instantaneous working current: 20A

I think that battery is too small. Every time you use the throttle on that 1000W AW motor, it will probably shut down, maybe not when fully charged, but quite quickly after you use about half the capacity. The ad says it's for 250-500W motors.

Yes, the AH will be greater for a pack that can support more current.
 
Dang, I was hoping I could get away with using that one because it's so cheap and if I like the battery, get a second one to put in-line with it on my rear rack. What's odd is that they have a 15ah 48v that goes to like 25a I believe, that they recommend for 1000w but its 100 dollars more just for 3 more ah and unless they just copy and paste the descriptions, the weight of the battery and the dimensions are exactly the same which seems fishy to me. It made me wonder if it's a scam and that they have the same capacity, just that their alleged 15ah is set to discharge faster. Is that possible? How is there a maximum discharge? What causes the limitation? And how is the discharge set? Is there a chip in the battery case or do you manually set the discharge rate from the controller? So far I haven't even got to wiring yet. I spent the last few days with very limited free time just putting on the back wheel, torque arm and brakes! Haven't even looked at the controller and throttle yet.

I hope my wires are long enough. Do people ever encounter that issue? If so, I wonder if theres some sort of extension wires I could buy on Amazon and what they're called. I've had problems every step of the way with this bike so I'm starting to just expect it lol
 
I bought a Sun ebike battery from a warehouse in LA, and it was garbage. Wouldn't even put out
5 A without the voltage collapsing to 11. I tested it with a 15 ohm 225 watt load. It was specified at 50 amps discharge, 17 AH 48 v. That warehouse may be a place that buys up the rejects and resells them, maybe overseas origin is new product. I can't tell. i bought a lunabike battery from LA at twice the price & it works. Among US warehouses where your card # doesn't go overseas, somebody else likes californiaebike and another guy likes ebikeling. I got a good motor/controller/pickup/throttle kit from ebikeling.
 
David, it appears you've jumped head first into the ebike world.
What's odd is that they have a 15ah 48v that goes to like 25a I believe, that they recommend for 1000w but its 100 dollars more just for 3 more ah and unless they just copy and paste the descriptions, the weight of the battery and the dimensions are exactly the same which seems fishy to me. It made me wonder if it's a scam and that they have the same capacity, just that their alleged 15ah is set to discharge faster. Is that possible? How is there a maximum discharge? What causes the limitation? And how is the discharge set? Is there a chip in the battery case or do you manually set the discharge rate from the controller?
They might just "copy and paste" the descriptions but that's not likely.
Scam? Doubtful, it might be a good battery, it might be a bad battery.
"set to discharge faster." The amount of discharge, in this case, watts from (most) ebike batteries will depend on the individual cells, the gauge of wire, and the BMS (Battery Management System).
Some good info on a battery BMS from EBR is here.

it's so cheap and if I like the battery, get a second one to put in-line with it on my rear rack
2 of those batteries, in theory would provide enough watts for your build. "Maximum continuous discharge current: 15A" 15A + 15A = 30A x 48v = 1,440 watts.
 
(I've been using and modifying electric bikes since 9/8/2000.)
Some basic truths about watts and power:
The amp capacity is like the size of a gas tank; the discharge rate is how fast you use that capacity.
The controller limits the amps output.
Watts are volts times amps.
The motor rated at 1000 watts is not a fixed capacity. I've seen tests where a 250 watt motor was drawing 655 watts for extended periods.
So a 1000watt motor, depending how honest they are on capacity, could draw much more power/watts than rated, or, not as much as rated. (my 750 watt hub motor draws up to 1200 watts with the controller it came with.)
In my experience, manufacturers and sellers often can make claims that are idealistic at best, or downright wrong, regarding distance, battery and motor ratings.
However, the faster you ride and the less you pedal the quicker the battery will drain. And lithium batteries give very little warning. Most batteries (lead/acid, alkaline, and nicad) drop voltage slowly so if you monitor the volts you know where you are at and just put out less and less power; whereas lithium batteries maintain pretty close to the same voltage, and then quickly drop off like a clif, and zero power.
Best to have a LCD on the handlebars, which helps a lot, but you can still be surprised by a suddenly dead battery.
So, Lithium batteries wear out, just like any battery. one to 3 years in my experience (I've been using NMC lithium batteries. Nickel, Manganese, Cobalt)
 
I'm using their 14ah battery on my wife's conversion, using a KT display, controller and Leaf 1000w DD motor (purchased together as a "kit"). We're recreational riders, and generally run at speeds well under 15mph. It's been going strong for 3 years now, and given me no reason to believe it won't go 3 more years. Has about 1500 miles on it.

Point being, maybe it's not a top drawer battery, but not all of us need a top drawer battery to get the job at hand done.
 
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