Why Is my scooter struggling battery sag?

General Discussion about large electric scooters and motorcycles and other things with no pedals.
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emotivemick   1 mW

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Why Is my scooter struggling battery sag?

Post by emotivemick » May 28 2018 2:32pm

🤔 specs 6x 12v 40ah deep cycle 72v excelleration rubbish am avoiding hills as it won’t go over 20mph up them it will reach 55mph+ but on flat eventually

emotivemick   1 mW

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xero erban tourer

Post by emotivemick » May 28 2018 3:32pm

advice needed on lack of power
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emotivemick   1 mW

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Re: Why Is my scooter struggling battery sag?

Post by emotivemick » May 28 2018 3:42pm

bike is xero urban tourer all 6 batteries are new 5kw hub motor
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billvon   1 MW

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Re: xero erban tourer

Post by billvon » May 28 2018 4:22pm

emotivemick wrote:
May 28 2018 3:32pm
advice needed on lack of power
Twist throttle more
--bill von

emotivemick   1 mW

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Re: xero erban tourer

Post by emotivemick » May 28 2018 4:39pm

:lol: if only i could bike accelerates great on stand instant power under load its a snail

Voltron   1 MW

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Re: xero erban tourer

Post by Voltron » May 29 2018 12:36am

What kind of battery is in there? Whatever it is could be unbalanced, or if it's lead acid sulphated and unbalanced at the same time. Good on the stand but bad under load is the battery 99% if the time.

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flippy   10 kW

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Re: Why Is my scooter struggling battery sag?

Post by flippy » May 29 2018 6:08am

i expect you have a really crappy controller nerfing the power uphill. it also does not help you have 100kg of shitty lead in there.

hook up the DMM so you can drive with it. measure the voltage on idle, flat and uphill goiing full speed and report those voltages back. some specs on the controller would also be very helpful.

personally i dont think things change unless you replace the lead with lithium and a different controller. if the motor is truly 5kW you can make this a real monster.
Lithium beats liquid dinosaurs.

emotivemick   1 mW

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Re: Why Is my scooter struggling battery sag?

Post by emotivemick » May 29 2018 4:58pm

stripped it down removed 95kgs of lead charged them up separately to balance and looks like controller is a kelly programmable via rs232
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flippy   10 kW

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Re: Why Is my scooter struggling battery sag?

Post by flippy » May 29 2018 5:03pm

get a cable from kelly to reprogram that thing.
still make the voltage measurements mentioned before but order the cable sooner then later.

can you read the model number?

if you got rid of the lead and get lithium you could make it a real sleeper on the street... :twisted:
Lithium beats liquid dinosaurs.

emotivemick   1 mW

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Re: Why Is my scooter struggling battery sag?

Post by emotivemick » May 29 2018 5:15pm

what do you think of making a 72v battery from 18650 cells seems common but they always seem to use new Samsungs etc at £4 each in uk that would be 400 x £4 for 72v 40ah (3,7v 2ah batteries) cant justify that but can get 100 laptop batteries new old stock 6 cells at 2.2ah each for £250 (600 cells) anyone used recycled laptop batteries in a higher power application :?: :?: :?:

emotivemick   1 mW

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Re: Why Is my scooter struggling battery sag?

Post by emotivemick » May 29 2018 5:20pm

cant see any model number i will get a usb to rs232 and have a play looking at kelly site now for software :)

Voltron   1 MW

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Re: Why Is my scooter struggling battery sag?

Post by Voltron » May 29 2018 5:32pm

Big rectangular prismatic batteries like Leaf or Fiat etc modules might be easier... Fewer interconnects, and depending on the type unboltable to replace a dud cell in the middle of a pack. The battery bay on those kinds of scooter typically like big squarish blocks of things...

Like this sort of.... except not looking like it was wired up by insane elves, and not all puffed beyond all use.
old pack.JPG
old pack.JPG (225.66 KiB) Viewed 487 times

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Re: Why Is my scooter struggling battery sag?

Post by Voltron » May 29 2018 5:42pm

Its a low tech way to do it, but for testing big SLAs like that I use a rig with an inverter that runs on 12v, several lamps, and a clock with hands from a thrift store. Once its hooked to a battery with the lamps running, it will go by itself in a fairly safe manner, and when the inverter reaches a low enough voltage, it turns itself off, like it would to save your car battery. Then the clock shows how long it ran (digital clock wont work), so you don't need to watch it every second.

Then you can get a set that all run for the same length of time, so the pack isn't constantly trying to unbalance itself.

emotivemick   1 mW

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Re: Why Is my scooter struggling battery sag?

Post by emotivemick » May 29 2018 6:12pm

trouble is i live in uk they build the leaf batteries here but you cant buy them here unless you want to pay £4000 up for a crashed car pack i have seen a second hand leaf with an on the road price of £5,500 the batteries are rarer than hens teath in uk :?

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flippy   10 kW

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Re: Why Is my scooter struggling battery sag?

Post by flippy » May 29 2018 11:40pm

what range do you need/want?
Lithium beats liquid dinosaurs.

emotivemick   1 mW

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Re: Why Is my scooter struggling battery sag?

Post by emotivemick » May 30 2018 2:00pm

think your right its just cost to go lithium i am going to have a mess with some 18650 batteries see what actual power drain is just got to learn how to do it :? need to read some of the posts on here goona make a 12v batt from 18650s and test against one of my lead bricks

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flippy   10 kW

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Re: Why Is my scooter struggling battery sag?

Post by flippy » May 30 2018 5:01pm

you cant make a 12v battery with 18650's , the voltages are all wrong. you can make a 48v battery that matches the voltage range of lead but 12v wont work.
Lithium beats liquid dinosaurs.

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LockH   100 GW

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Re: Why Is my scooter struggling battery sag?

Post by LockH » May 30 2018 5:38pm

Hard to pedal? Bike heavy? Oh oh...

Yah can pedal most any bike for warmth or exercise, but in "EV Terms" you MUST pedal from stops, help up hills, etc to shave off any/all peak power outs. To extend ranges per charge, but also to "baby" any cell chemistry, such that the cells ("battery") last longer before final recycling and replacement? ie to minimize costs per mile. Done "right", about the same costs per mile as any pedal-only bike, just with less poops per mile. And any "heavier" vehicle comsumes more energy to accelerate or go against gravity ("up" hills). Also, make yerself as aero - aerodynamic - as you can. The "faster" you go... air "wind resistance" increases... watt takes more energy... yer wind screen's there for a reason. :wink:

To go "further"... go "slower"...
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otas   100 mW

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Re: Why Is my scooter struggling battery sag?

Post by otas » Jun 26 2018 5:06am

I am in a similar position, I have Erider Model 30 with 5 x 12V 20A led acid batteries not even 2 years old. My range is hardly 12m. On flat I can reach 30mph. Uphill it struggles. From 62V it drops under load to 54V whilst drawing 17A. So I am thinking about hybrid. IC generator 4 stroke and smaller Li-ion battery. Generator to produce some 600-800W for flat run, and 17S4P Li-ion battery for acceleration. Any comments on this :?:

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flippy   10 kW

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Re: Why Is my scooter struggling battery sag?

Post by flippy » Jun 26 2018 11:22am

My comment: its stupid.

There is no reason to just put a bigger battery in. A 16S25P battery is a drop in replacement if you still have the original controller (but i seriously recommend a 180~300A kelly so you can up it to 72v) and then you can drive almost 100 miles on a single charge at 30mph. Bigger battery lives much longer then a dinky ass 4P pack.

Bigger battery is lighter, more exonomical and gives you a LOT more power. You can get 200Amps from such a pack easy. Put down a 4kW motor from Qs and yoy can make burnouts...

15kW is a wholr different game then a standard crap controller capped at 2kW
Lithium beats liquid dinosaurs.

emotivemick   1 mW

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Re: Why Is my scooter struggling battery sag?

Post by emotivemick » Jun 27 2018 2:34pm

after waiting ages for bits i have conected my controller KEB72801AJ and turned up battery from 45% to 70%
it still bogs on take off after i hit 10mph it pulls ok upto 55mph drawing max 38amps
yet i can get it to pull 80+amps on stand
:x
put in cheep amp meter its ok would recomend at £20 not a CA but not bad
think batteries are problem?????????????? yet this is how they tried to sell new its no wounder it floped

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Re: Why Is my scooter struggling battery sag?

Post by emotivemick » Jun 27 2018 3:40pm

i think excelleration and hill climbing require a good c rating which seems to mean the ability to deliver the amps as fast as posible without killing the battery,motor or controller i was looking at getting an erider 30 and putting in headway cells as these seem to be tried and tested and available in uk at £15 for 10ah cells you would need 38 cells but 40 is normally used in 60v nominal (actually 64v charges to 72v) + conecters for batteris 60v 20ah but lithium so far better range less sag but you would have to make sure wireing is up to taking current draw some 15ah lifebats were on ebay not long ago at £8 each at 15ah bargin i might be wrong butyou learn nothing from being wright so please correct me :)

emotivemick   1 mW

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Re: Why Is my scooter struggling battery sag?

Post by emotivemick » Jun 27 2018 3:55pm

this is the amp meter i put in scooter sorry for bad photo sun is to bright but tested it out of scooter reeds volts amps watts wh
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flippy   10 kW

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Re: Why Is my scooter struggling battery sag?

Post by flippy » Jun 27 2018 11:59pm

see how far the voltage tanks under full load, that tells a lot.
Lithium beats liquid dinosaurs.

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LockH   100 GW

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Re: Why Is my scooter struggling battery sag?

Post by LockH » Jun 28 2018 12:16am

... and you DO realize that manufacturers rate their battery capacity/distances based on an ambient temp. of about 20C? ... and assume you're 100% "running the battery dry"? In the daze of running lead, used to cut claimed distances about in half.
ES changed my life (for the waaaaay better).

Eff. June, 2014 Phoenix Ebike Promotions

(Current ride? High speed lawn chair.)
viewtopic.php?f=3&t=57408

Phoenix Ebike Promotions conversion kit (work in progress. More drink holders, etc etc)
viewtopic.php?f=15&t=60564

Joined yer local chapter of EA yet?
(Ebikers Anonymous - Where we're all miserable failures, but the parties are hilarious...)

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