Lead Acid vs. Lithium Based vs. Nimh and other Batteries

[GTA1]

OK, here is a new thread on what are the possibilities for extending conventional lead acid, Nimh, and other battery technologies as opposed to using different iterations of Lithium batteries.

Previous posts can be found here:


http://endless-sphere.com/forums/viewtopic.php?f=4&t=9500&p=162012&hilit=lead+acid+battery#p162012


http://endless-sphere.com/forums/viewtopic.php?f=7&t=9482&p=162384&hilit=lead+acid+battery#p162384


I will start by saying that for the average user, relatively low cost lead acid batteries, or enhanced versions of them like AGM batteries, offer a cost effective solution that is superior to Lithium based technologies.

 

[chvidgov.bc.ca]

SLAs are too darn heavy, the voltage sags too much under load, they die if not handled with kid gloves instant recharge-wise after use, and and they pollute the environment with heavy metals as a byproduct of silver mining with moonscape tailing ponds scattered about the landscape. And they cost more to ship because of their weight. And you need to keep buying them all the time. They are like Kurt Vonnegut's character, the Handicapper General Dianna Moon Glampers, who hung big weights off ballet dancers to "level the playing field". What's not to like?

 

[Drunkskunk]

What?
lead?

Even Safe stoped arguing that they it much benifit.

Lipo can be had as cheap as $0.25/WH, making it often cheaper, longer lasting, lighter, and more enviromentaly friendly than Lead, and thats not even the best option.

NiCad is far supperior to Lead. its the bottom rung in Acceptable battery technology. but it's a solid preformer with cost of ownership being less than Lead over the life of the battery.

 

[velowatt]

I have to agree, lead-based batteries are stoopid heavy. They are cheap, though. I have gone through 2 sets of 12Ah 12V SLAs in 3 years, and have gotten over 2000 miles out of 'em. They still are usable, just have gradually less and less range. Most of my trips (commuting to work, store, etc) are short and hilly, and I charge 'em up immediately every time. I have been running 36v, and for an occasional long commute (20 mi each way), I started taking 2 packs (in panniers, each side of the rear wheel), 30+lbs EACH, and connecting 'em in parallel. This really cuts down the 'sag', and extends the range by several miles (I also charge at work when possible- I look pretty funny lugging 60lb of lead, plus a bike-bag briefcase full of chargers through the hallways at work).

A few months ago, I started using 48V (4 batteries). I went on a long ride (40 miles) in the rain with 70 lb of batts (1 36V pack and 1 48V pack, made of what I thought were old tired batteries). I was amazed at how much energy these things still can store, but MY GOD THE WEIGHT!! My panniers are now ing through, my rear rack (held all the batts, chang of clothing, controller and chargers, extra tools, etc) has become bent and crushed out of recognition, and my rear tire blew on a pothole (1 block from home, luckily). Every time I hit bump it sounded like an avalance was chasing me. (My bike is a recumbent with a rudimentary suspension. The ride is not bad, but anyting on the back rack gets the shake treatment).

I am so gonna get a lithium battery. Need to build a new rear rack first. I have got an idea to make a 'suspended' rear rack that I think I will try. The good thing about the crappy old lead cells is they got me started out onthe cheap- I dont think I would have invested the $$ in lithium or NiMh cells of 2-3 years ago. Now the better technologies are getting more affordable.

 

[swbluto]

They are cheap, though.

If you're anything more than a casual or short-range user, they are definitely not cheap over a period, like say, more than 3 years.

 

[GTA1]

AGM Lead Acid batteries build for deep cycle would be my choice for mid priced, reasonably durable batteries for a cycle that gets maybe 100km a week during 8 months of the year.

 

[GTA1]

I took apart my lead acid Schwinn iZip (2008) model.

Found what is inside the plastic case is 2 standard gel cel (sealed lead acid) batteries of 12V-12Ah.

NP 12-12, made by everybody and their brother.

Standard product that is available nearly everywhere for $35 a piece or less in quantity.

http://www.apexbattery.com/yuasa-np1212-battery-sealed-lead-acid-batteries-yuasa-batteries.html

This pair of batteries give me a 15km range (nearly 10 miles) with a 25% safety margin, recharges in 6 hours.

The replacement from Canadian Tire (including the plastic case, switch) is CAD $120, or about US $100.

Not bad for a year or so of use.

 

[vanilla ice]

I agree with swbluto. If you're a casual, short range user lead can work for you, and work well. If you never use your ebike to go farther than a few miles whats the point of extra range? If you're so casual that calendar age kills your pack before it cycles out, well it doesn't matter how many cycles the pack will do eh? Another thing, I've been able to score 12ah bricks at a lot less than $35 a pop.

 

[Kurt]

Let me do a price comparison using my wifes little 36v folding bike.She runs two headway 36v 10ah lifpo4 packs but can easely run her bike on just one pack and get the full 10ah from the pack. They weigh about 8lb and is about the size of 4 softdrink cans. They cost $400 AUD each.

If she was going to run agm (lead acid) battery's you have to compare apples with apples she would need 3 X 20ah to give her something close to the same range and performance as lithium. You would need to pay around $80 AUD each for the 3 battery's if you wanted reasonable Q. That's $240 total so the AGM's are only 40% cheaper than her $400 lifpo4.The agm pack would be 3 times the size and 3 times the weight of the lifepo4.The lithium will last 10 times as long for 40% more in initial cost.


Lifepo4 is that cheep now and because the lithium gives you its full rated capacity you can get away with a smaller AH size.Weight, size and longevity are just not in lead acids favour. I think calendar life is more of a problem with SLA than lifpo4.

Using AGM battery's is kinda like putting a 1 gallon gas tank on your car and saying its cheaper to run because it only cost $5 to fill your car up.

Kurt.

 

[vanilla ice]

Using AGM battery's is kinda like putting a 1 gallon gas tank on your car and saying its cheaper to run because it only cost $5 to fill your car up.Kurt.

But if the 1gallon gas tank itself costs less than the 5gallon tank, and you never need more than a gallon's worth of range..

 

[fifthmass]

My lead acid set (48 volt 10ah, 28 pounds) that I got with my Electric Rider kit is good for 16 miles easy with my 408 and 18-19 if I really baby it. Granted I do pedal but I am able to get 6.7 ah out of a 10ah pack which is not too bad. I have since moved on to lifepo4 but keep the leads on a trickle charge as a spare.

For a 10ah or less pack Justins 8ah Nicad pack (19 pounds) seems like a decent selection and a decent step up from lead.

Bill

 

[TylerDurden]

Non-lead chemistries also provide the ability to fast-charge at destination, so less capacity is needed for a round-trip.

 

[GTA1]

Using AGM battery's is kinda like putting a 1 gallon gas tank on your car and saying its cheaper to run because it only cost $5 to fill your car up.

Let's do the same compare with your Lithium battery against my 50cc, 5hp moped engine with 1 gallon of gas....

Or a 500cc Sport Bike with a 5 gallon tank....

 

[TylerDurden]

Let's do the same compare with your Lithium battery against my 50cc, 5hp moped engine with 1 gallon of gas....

Comparing fuel types to each would be more analogous. i.e. E85 v. Nitro

 

[torker]

Short range and limited use describes my riding. I just started and am using lead.
1: because I traded a radio antenna for the first two on my 24v bike.
2: because I already had 1- 7.5 ah for my second build so only had to buy 2 more@
21 dollars each. I would love to have lipo or similar but can't justify it yet.

I live in a really small town. 9 mi. from the nearest town and don't like riding the hiways or 55 mph. county roads with no shoulder so I mostly zip around the town or take the least used county road out a few mi. in the country. If I were commuting or had a safer/ larger area to ride it would be lipo or similar for sure.

Also I noticed BB battery has several different styles of agm . One shows 25Mohms internal resistance and they have one with 15Mohms res. Anyone tell me how much difference that might make in the real world?

 

[Kurt]

The only advantage to SLA is if you dont have a battery for your ebike and want to make it functional for the smallest amount of money sla is the cheapest.In the same way that dial up internet is the cheapest and better than nothing.

Kurt

 

[vanilla ice]

Right, and just because we here are not old ladies who only use the web for hotmail.. that doesn't mean we interweb experts should try to convert all the old ladies out there to broadband. This old lady is perfectly happy with my dial-up thank you very much.. err this dude is happy with sla. Obviously Its nowhere near as good as lithium (does that really need to be said?) but it still has its place. At least for now.

 

[GTA1]

Right that doesn't mean we interweb experts should try to convert all the old ladies out there to broadband.

Applause.

This "little old lady" here is perfectly happy with the 15km range.... with the median trip less than 1km.

I leave my bike out on the rack, with a $5 lock and cable, with the smug satisfaction that if it is stolen, the replacement cost is USD $300 or so.

Can't imagine a thief wanting to make off with my battery either....

Can any of you people that is on lithium do that in most parts of the country?

 

[gogo]

I leave my bike out on the rack, with a $5 lock and cable, with the smug satisfaction that if it is stolen, the replacement cost is USD $300 or so.

Can't imagine a thief wanting to make off with my battery either....

Can any of you people that is on lithium do that in most parts of the country?

Advantage: SLA

 

[dogman dan]

If the longest ride I did was 8 miles of flat ground, I might still be using 48v, 12 ah sla's. Especially if the usual ride used the sla's to 50% dod. The weight is not that big an issue for slower rides or shorter rides since the beating they give the bike is not for so many miles. It all just depends on your needs. If a set of sla's gets you a year of riding, it may not be cheaper per mile but it sure is cheap enough. Where sla's start to get lousy is when you need to climb a steep hill, and then the weight screws you.

But I bet an sla user with a 10 mile ride than switched to nicads wouldn't go back to sla's. Nicads really rock for a bike that is rode less frequently, like a weekend bike. They are close to idiot proof, relatively tolerant of deep discharges, can do 5c, and have super long shelf life. The disposal issue is a big deal, but they can be recycled at most places that sell cordless tools. They are not that light, but anything is light compared to sla's. They do have some voltage sag, but nothing like the sag sla's have.

Lifepo4 or other chemistries cost a lot up front, but the longer ranges possible for a mere 15 pounds of battery is worth the up front cost. For really long rides a lighter battery is so much nicer since you can carry more ah than other chemistries like nicad or lead.

 

[GTA1]

The big disadvantage with Nicads in an motive power application is that they have memory - and our normal routine of recharging to full after each ride that does not discharge them fully results in a much lower capacity cell.

NiMh, on the other hand, offers little or no memory effects.

On all round cost, efficiency, economy, NiMh would be 2nd on my list next to Lead Acid / AGM deep cycle batteries.

You can actually get D sized NiMh sizes out of China cheap, and chargers are easy to rig up... and a heck of a lot lighter than SLA.

Now.... if we can only steal Toyota Prius batteries and reverse engineer their battery management software....

 

[TylerDurden]

The big disadvantage with Nicads in an motive power application is that they have memory - and our normal routine of recharging to full after each ride that does not discharge them fully results in a much lower capacity cell.

Typically not true in ebike applications. Easily recovered anyway; with periodic complete discharge to break the crystal formations.

As for lithium security, they are light enough to carry-in (and recharge) at destinations.

Nimh lifespan is a non-starter. Nicd go and go and go and go....

 

[jolly]

NiCad never had a 'memory' problem, that is a modern myth. SLA is useful when someone is just getting started in the ebike world and isn't sure if it will be for them. When the SLA wears out in a year, they will know how much they use their ebike. If the ebike turns out to be useful for their lifestyle, then it would be worth it to switch over to Lithium. My bike handles so much better with lighter batteries and they take up so much less room.

 

[dogman dan]

Yup, the real problem with nicad in drills was how we used em, not realizing that it was bad to partially charge them, not to charge them when partially discharged. My first set of drill nicads lasted a few months, subsequent ones decades. Got some good ones in my garage now, 15 years old. But, yeah, if you use the bike daily, or even weekly 12 months of the year, lifepo4 is worth it,,,, if you have the bux. But if it will be used say, 20 cycles a year, then nicads are actually a better choice since they won't die on you during the winter from some pesky tricke discharge. Monitoring the charge level on an unridden bike is kind of a hassle.

 

[torker]

I HATE VOLTAGE SAG !! 10 mph with pedaling on my last mile home :x SLA BLUES Hey since were on nicads a ? Anyone know what really kills nicads 90 % of the time. I bet I've got 3 old drills a weadeater, I'm sure some other stuff and weak nicads is the only issue. I am wondering about the chargers that come with these not doing their job or the cells just being subpar to begin with. I have heard and seen it is usually 1 cell that dies or reverses polarity from too deep discharge. What exactly is causing this? The only nicads that I've had really good luck with is my Hitachi drill batts. I use them at work and they probably have 200 cycles and rock,, Are they just higher quality cells or better charging system?