Battery for Ebikling 1200w rear motor

ruffruff

Active Member
Can anyone recommend a battery for the Ebikling 1200w rear direct drive kit?

Not looking for crazy Ah's-something in the 10-12-15 Ah range.

The controller is a 30 amp controller if that matters.
 
i say go for the largest Ah size that you can muster - i have a 20.4 Ah battery on mine (a polly DP-9 case with a 30A BMS) and on extended uphills at full power the battery voltage will sag quite a bit - it recovers pretty quickly but i wonder if I had only a 10Ah battery whether i would be able to push it to the low-voltage cut-off under these heavy load situations? if this issue is a problem, applying a lower PAS level might be the ticket, since the increase in power consumption vs. additional top speed is non-linear (you save a lot of current by losing a little top speed). i haven't tested whether the display's current limiting settings actually work - i was suspicious of it since some of the displays on these kits state a 20A max even though the controllers are 30A
 
by the way, if your motor is like mine, then the freewheel will drag a bit at first (e.g., forward rear wheel movement will want to turn the gear cluster and pedals) but will loosen up quickly to normal behavior. so like your first test ride will make you wonder what's up with range / top speed but on mine it loosened up pretty quickly to expected behavior
 

ruffruff

Active Member
Thanks for the heads up on the freewheel and the Amp suggestions.
What actual battery are you running?
 
I went with a Polly dp-9 from Susie at aijiupower.com but the case wasn't perfect since I originally wanted a 35a bms (if I ever wanted to try a 1500w kit) and that size bms would've required too much hacking at the case to fit... Anyhow the Polly + 30A bms I ended up with works great with the 1200w ebikeling kit.. I haven't gotten that many miles on it (maybe 100?) but i can floor it for the duration of the upside of the Manhattan bridge or the uphill side of the local 3 mile park loop without problem.

Re the vendor this is my third battery from Aijiu power, an Alibaba vendor, and I've been really pleased with them... I know people warn against straying from a local vetted U.S. distributor so caveat emptor, but there are a few other members on the surface 604 section who are pretty happy with them. It will take a few weeks from finalizing the specs to arrive at your door tho
 
I'm no expert but I think it's safest to select a bms to match or exceed the current rating of the controller... a bms with a certain current rating might not be set to trigger its fault protection until a substantially higher discharge current is encountered but unless you intricately know the details of that bms you don't want to risk it cutting off at an inopportune time...?
 

harryS

Well-Known Member
Yes. you want the battery to be able to deliver the same max current as the controller, if you plan to run the controller at max. Some battery sellers don't specify that max, but it matters if you have a larger controller. The max is a function of the number of cells in parallel as well as the BMS.
 

ruffruff

Active Member
So it would be ok to run a 50A BMS with a 30A controller?
I'm thinking of going with this

48v 20Ah 50A BMS for a 1200watt motor with 30A controller.
 

Thomas Jaszewski

Well-Known Member
So it would be ok to run a 50A BMS with a 30A controller?
I'm thinking of going with this

48v 20Ah 50A BMS for a 1200watt motor with 30A controller.
Those are generic Chinese batteries with nickel coated steel connectors (pure nickel is best)and a cheap BMS. Likely without a balance function. Some folks have had decent luck with generic cells. I sold a few with full disclosure but it is a coin flip. Ask them to upgrade the BMS to have balance functions and order a replacement BMS. Shouldn’t be more than $20 for a backup BMS. Failure with UPP will mostly be BMS related. For$20 you won’t have a dozen emails, a series of pictures, and just general jackassery to get you battery repaired.

i have their batteries, they are better than average, and now
they have a USA presence, but are still the bottom of the pack battery builders. 3% will eat their investment.
 

ruffruff

Active Member
Those are generic Chinese batteries with nickel coated steel connectors (pure nickel is best)and a cheap BMS. Likely without a balance function. Some folks have had decent luck with generic cells. I sold a few with full disclosure but it is a coin flip. Ask them to upgrade the BMS to have balance functions and order a replacement BMS. Shouldn’t be more than $20 for a backup BMS. Failure with UPP will mostly be BMS related. For$20 you won’t have a dozen emails, a series of pictures, and just general jackassery to get you battery repaired.

i have their batteries, they are better than average, and now
they have a USA presence, but are still the bottom of the pack battery builders. 3% will eat their investment.
Well that's not a promising report! LOL..
Can you recommend a better option?

It's pretty intimidating to shell out the money and not really sure what you are getting!
I've looked at a lot of AliExpress batteries as well and they seem to be pretty much the same as the Ebay batteries.
 

Thomas Jaszewski

Well-Known Member
Sorry, I'm a battery support fellow for a California eBike kit company. It's not cool to peddle my wares, but it is worth the extra bucks for a proper build and a REAL warranty.
 

ruffruff

Active Member
Sorry, I'm a battery support fellow for a California eBike kit company. It's not cool to peddle my wares, but it is worth the extra bucks for a proper build and a REAL warranty.
I appreciate it! As a new builder it's pretty easy to throw away a lot of money on junk if your not careful.
Thank you.