SLA vs. Li battery

[dkw12002]

I know Li batteries are lighter than SLA batteries, and give more re-charges, but they don't seem to be worth the extra price in all cases. If you want a really fast bike, I'm fairly sure you need to go with Li to keep the weight down if you still expect to pedal, but for a slower bike...say 14 mph such as with an Ezip, the SLA seems like a much cheaper alternative. My ezip bike was $350 and came with 1 SLA battery. I bought a second one for $95. With both on the bike, the bike is heavy, but with light pedaling, I can go 25 miles on the set up. I have an AmpedBike too. It is faster...23 mph and has a Li battery. Thing is, the kit was $900, not including the bike. It will go about 25 miles with light pedaling too, so the range is about the same. It looks to me like if a person is content to go a little slower, they can come out money ahead staying with a smaller motor and SLA. Opting for speed plus range gets very expensive in a hurry. The number of recharges is different between the two types of batteries too, so that advantage goes to Li. What applications, if any, do you think SLA batteries are a more economical choice than Li?

I'm curious who has the cheapest e-bike set-up? Anything cheaper than a $350 Ezip? Who has the fastest SLA battery set-up? Who has the longest range SLA set-up with light pedaling?

 

[Ykick]

To play with relatively cheap Li most of us turn to RC Lipo where you can carry a lot of range for a 14MPH bike in a 5-6lb package. Yes, upfront costs are more along with greater potential for accidental fire but you actually learn something current and relevant with regard to modern batteries. Lead's 100 year old technology...

 

[Ypedal]

Lead is Dead..

If economy is your biggesst concern, your needs are :

- short range
- slow
- ride comfort not an issue..

maybe..

however.. a small 5ah lipo pack can be had for 100 $.. weigh 3 lbs .. and do the same job as a 20 lbs lead pack... pedaling meaningfully means every lbs counts.

yes, there is a place for sla.. but not on any of " MY " bikes ! hehe..

 

[dogman dan]

I seriously doubt you are getting the same range. Something is different, the size of the battery, or the speed you ride, or both.

Unless I am mistaken, your lead is 24 ah. How big is the amped battery? 10 ah?

Nevertheless, If my ebike needs were limited to 5 miles per trip and 12 mph, I'd very likely still be riding around with lead. That EV global bike I had was perfect for that kind of trip.

For fastest and longest range, It's possible Safe still holds the records for a bicycle. Go back about 4 years for his threads.

 

[Drunkskunk]

Lead is almost totally worthless for ebikes. Almost.

If you happen to need an ebike, have flat roads, and a 5 mile or less commute, and are comfortable with 10-12mph speeds, Lead is an answer. That's the reason I will occasionally recommend the Izip. For some people, for some uses, Lead is the right answer.

But thats 1% of the time. For every other use, Lead is dead. With the falling price of LiFePO4, so are Nicads and NiMH.

 

[TylerDurden]

Lead is almost totally worthless for ebikes. Almost.

True.

Useful only for the purpose of showing a bike is functional before selling.

 

[Kin]

I don't know. SLA + trickle charger is a decent power supply for a Li charger.

More seriously, for most people I think 10mph is a reasonable biking rate. So you're adding a lot of cost and a ton of weight to go 14mph for a short range. To me, not worth it.


The trick is, your example is the only time it's worth it. If you're going very slowly. Even short range at high power, you'll run your lead down very quickly. Speaking from some limited experience with SLAs on electric scooters. When they die after 150 cycles, even SLAs are expensive.

 

[D-Man]

I'll bet most the millions of ebikes in China are still on sla's.

 

[SamTexas]

What applications, if any, do you think SLA batteries are a more economical choice than Li?

SLA specifically or Lead-acid battery in general? For lead-acid: Your everyday starting battery in your car. Can't think of another application.

Even for your Ezip, a good LiFePo4 (A123) battery is more economical than SLA in the long run, say at least 5 years or 15,000 miles. But you have to compare apples to apples. 14mph to 23mph is not apples to apples. At 23mph you consume more than twice the energy per mile than at 14mph.

 

[SamTexas]

I'll bet most the millions of ebikes in China are still on sla's.

That does not mean SLA is more economical. It means it's easier for them to sell, because SLA ebikes are at a price point that is affordable to the populace.

 

[Matt Gruber]

How long do Li last, how many years?
My red scoot has SLA from 2003. that is unsual for sure, most of the others from 03 are long dead.
2 of my car LA lasted 10 years. is this possible with Li?

 

[dogman dan]

Bet those chinese riding the lead bikes live closer to thier workplace than typical Americans too. So lead works for them. Wouldn't work for me, living 15 uphill miles from my workplace. Could have worked though, if it was 15 flat miles. I went lithium in the first 30 days, because I HAD to. Just couldn't lug lead weights up that huge hill.

 

[SamTexas]

More seriously, for most people I think 10mph is a reasonable biking rate. So you're adding a lot of cost and a ton of weight to go 14mph for a short range. To me, not worth it.

Yes, for most people 10mph is the average moving speed on a regular bike. A jump from 10 to 14mph is very significant. That's 40% improvement, well worth for a $300 to $700 investment. The small (150 to 300W) added power may look insignificant to a bystander, but to the actual user it's humongous: Suddenly all the hills now appear flat. Head winds magically disappear. Starting from stop is no longer a strenuous task. You arrive at your destination not soaking in sweat.

A ton of weight? A small geared hub + a small controller + a small 200 to 300wh LiCo battery weigh what? 20 pounds? Probably less. Add 5 lbs if you use the safer LiFePo4 battery.

 

[Kin]

Oh! Sam, I'm just talking about the heavy SLA version of that scenario. I think a 350 watt or even 250 watt with some Lico batteries is a beautiful solution [LiCo of the dense laptop kind].

I am not going to argue about the 14mph deal. I think many people are differently physically abled for many reasons (whether age, life, whatever). For my use, though, 14mph is slower than a comfortable regular biking speed, let alone a fast version. So, of course, things depend from person to person. I have an older coworker at work (slightly redundant) for whom I recently started keeping an eye out to pick up a 250 or 350 watt hubmotor next time one is steal-priced on the forums.

 

[SamTexas]

I am not going to argue about the 14mph deal.

What's to argue about? Everyone has his or her speed. One person's ideal speed has nothing to do with another person.

 

[Kin]

I am not going to argue about the 14mph deal.

What's to argue about? Everyone has his or her speed. One person's ideal speed has nothing to do with another person.

Oops, I'll try to use less ambiguous wording next time. I agree with you. I'm not saying that "I'm not going to argue with you because you're wrong" but rather I'm saying "I don't disagree with you about the speed thing [everyone indeed has their own speed]"

I'm not arguing, just because there's nothing to argue about

 

[nechaus]

Im over leadacid batteries for ebikes..
they are good batteries if you have a real low discharge and don't need to move them around..
i have a few in my shed like 40 ah 12 volt powering about 10 watts of leds... they last a long time, and i just charge them up once a week