E-scooter needs Help!!!

SuperDave

SuperDave

Member
My wife 'won' a dollar raffle for a used 48v electric scooter. It HAD a top speed of 20, but the batteries were weak, 10 minutes in & power meter showed 20% left. One of my neighbors works at a scooter rental shop & hooked me up with 4 used motor scooter batteries on the cheap (backdoor sale).

After fully charged from a 2 amp, 12v trickle charger, now the bike winds up to only 10 mph! Are these batteries bad? Not enough amps? Supposedly these batteries have the same amperage rating(12Ah) than the stock batteries, but I was hoping because motorscooters must crank over a motor, they might discharge faster, allowing for quicker acceleration & maybe higher top speeds at the expense of longevity. Yet if anything, the opposite is true. Did I screw up? Locally, lead/acid motorcycle batteries are cheaper than than e-bike batteries($45 new vs. $60), at least the LiPo's or NiCad's anyway(up to $1200.00!!!).

And what advantage do other type batteries have over lead/acid? If I'm gonna shell out $1200 for 48 volts, it better last a month between charges and peak out at 50mph for that kind of money. The bike didn't cost that much new! Please help, wife is upset she can't tag along with me when I cruise around on my pedal chopper.
 
Well...if the new batteries are giving only a fraction of your former top speed, then I've got to wonder if you've actually got 48 volts going? Can you confirm this? For instance, do you have four 12 Volt batteries hooked up in series?

As far as the pros and cons of the different types of batteries goes I can only speak in generalities since I don't have much experience.

SLA's are probably the best bet for newbies. They are less expensive, if nothing else. Also you don't have to be an electrical engineer to charge them properly. Or to charge them 'well enough'. One downside to them is that they really don't last all that long. Deep discharging and recharging is not their strongpoint and they really should be viewed as an item that is 'consumed' as opposed to a component that might last the entire life of the vehicle.

The 'higher tech' batteries have some attractive pros. They'll pack more energy into a lighter package than lead/acid batts. There are a few, such as nickel/cadmium or nickel/manganese, that (I think) are not terribly pricey and that (I think) don't need to be treated as gingerly as some of the lithium types. But I do get the impression that they can be ruined quickly and easily if not charged just right.

And there are lithium-ion and lithium/phosphate type batteries. These clearly have the advantage of packing a lot of 'get-up-and-go' into a surprisingly light package. But the cells themselves plus the proper charging equipment quickly turns into a whole lot of money. And it seems that it's not hard at all to damage these batteries and that a flash fire is a common result of such damage.

I know of a guy who frequents another forum dedicated to electric vehicles. From his posts I can see that he puts a lot of effort into designing and building battery packs. He measures and reports results and such. He put things in a nutshell once. "If you want to plug it in and go to bed, then these are not the batteries for you". He was talking about either lithium ion or lithium phosphate. Can't remember which, but they seem to be pretty similar.

I've seen a video of a battery pack on a bike erupting into a flash fire. It's something to be avoided at any cost.

I kept up an electric bike for a few years. Ran it on SLAs. When it was at it's best, it was pretty good. But I had to put a lot of effort into keeping it, or getting it back to, at it's best.

I considered going to lithium-ion or lithium phosphate. But it seemed pretty clear to me that I didn't have the knowledge to do it without risking my wallet, a burnt down home or burns to myself. I chose not to do it without a good deal more knowledge.

So I went back to the internal combustion engine.

But to get back to the real point; it's probably not a good idea to try the high tech batteries without the knowledge to use them safely. I'd be inclined to recommend sticking with the SLAs. While they'll give you some headaches, it's the alternative most likely to work best for you.
 
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Motorcycle batteries are designed to start engines. Lotta amps for a short time. Electric vechicle batteries are designed to put out less amps for a long time.

I suspect you have some worn out batteries.

If you want to have fun get a 48 volt, 15 AH Ping battery. Should have about a 30 mile range. Should cost about $600.
 
Bluegoat, I wired them exactly as before, paired in series. That's so the factory charger (24v) plugs in properly without having to disassemble the battery box to charge daily, just plug in & go, charger stops automatically. The limited info I've found online states it's a 48v scooter, but charger is only 24v. (3 pin, one negative & a pair of 24v positives)

Mike B, these batteries were not new, only 'Reconditioned'. In other words, the vendor topped off the cells with fresh battery acid & charged them up to 12.6 volts. No telling if the batteries' available amperage matches what is stated on the label. Bike originally came with SLAs, so I assume they are the equivilant to a deep-cycle battery. New replacements cost $60.00 each, while used motorcycle batteries only cost me $10.00 each. I went this route for 2 reasons, cost & grunt factor - if the wife wants her e-scooter to keep up with my 66cc gas powered pedal chopper, she's gonna need every advantage I can throw at it. I'm also researching controller mods to exceed the built in speed limitations. Better wires & cables will be manditory, perhaps replacement motor brushes too.(2 wire hub).

From the feedback y'all are providing me, I'm thinking the batteries I have are whipped beyond redemption, looks like I'm gonna have to break down & spend more cash than I was initially willing to.

Get this: the e-scooter actually comes with auxillary pedals that fit into sockets on the sides, I guess in the event of total discharge, you're not completely stranded. Pedals are hidden inside the 'trunk' along with 2 screws & a screwdriver, under the helmut (yes, it even came with a helmut as a bonus, not bad for a dollar raffle!) So it counts as a bicycle.

Now I'm wondering if I can retrofit a China Girl onto this thing, make it into a real scooter. Pedal drive chain is on the left of the wheel, I could axe the pedals and use the sprocket for the motor drive, using the hub e-motor as a starter, get it up to speed using volts before engaging the clutch. Its an idea...
 
MikeB told you right, M/C batteries are not what you want no matter how cheap. 12ah SLAs are all over ebay for $24.95 including free shipping. If you don't want to invest in a high$$ battery go for the SLAs.
 
The cheap sla's that come with these chinese scooters are the weak point. Buy new and replace often is the best advice I can give.
Upgrading to a real battery will easily cost several times what a new scooter would run.
 
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