lead acid batteries

[latecurtis]

what is the real deal with these. are all lead acid batteries the same or are some better than others when it comes to weight
per Ah. I have a 24 volt currie ezip trailz. hobby king has cheap lipos but they are rated in millAhs. converted th Ah the biggest single battery is 8000 or 8Ah. its also around $100 for one. the 4s 5000s may be only $23 dollars each but will need 8 of them to get 20Ah and will be incompatable for my controller as it exeeds the max cutoff volts. the 8s for about $100 is 25.9 volts and will work but will need two just to equel 16Ah. three for 24Ah which is what I need.
lead acid is a much better option. two 12 volt 22Ah or better. I will mount them on the lower crossbar of my triangle with gorilla tape. I already tried it with two 12 volt toy batt. one was 7Ah the other 8Ah. I wired them in series to the controller then wired each of them in parrell to the two beat 12 volt 10Ah beat batteries i ripped out of the currie case. I had to solder the connectors on the one currie as they were broke off and flush with the top of the battery. I soldered the wires and taped them. this all charged up and worked. but not much better than the curries. all these batteries are beat. I need two good ones on the crossbar. please let me know where to get them. they cant be over 3 inches wide so i can gorilla tape them in.

 

[Ykick]

lead acid is not a better deal for daily use and/or enjoyment of a LEV.they’re not all created equal - majority intended for “standby lighting” service.and in addition, will only deliver rated capacity at very low current draw. when used for EV’s or high current service good luck realizing 1/2 labeled capacity.so double up those SLA Ah figures in addition to the extra weight and bulk.there’s HR (high rate) SLA but cycle life for EV’s sucks big time.i ran HR SLA for couple years and needed to replace every 3-6 months.and that was after i figured out how to not kill ‘em prematurely.i then used RC Lipo over 3 years before replacement which only weighed about 15lbs while SLA delivering 1/2 that range weighed 25-30lbs.if i were unable to charge at work i needed almost 60lbs of lead to match 15lbs RC Lipo range.never mind you can’t charge SLA at high rates and they’re very limited for delivering high current.if you just want a weekend toy to ride around a block every once in a while go ahead and talk yourself into it.but from somebody who’s lived with SLA on a daily commuting basis, no way.

 

[Sunder]

Curious about this, so I'm going to do some maths.

So found this as my baseline. Don't know if this is cheap or not, but it was the first result on Google:

http://www.amazon.com/22AH-Sealed-Lead-Battery-Universal/dp/B005PWULQQ#productDetails

2 of those will give you a 24v, 22Ah battery at 25lbs, and will set you back about $110./

Let's assume since you're using lead acid and at 24v, you're more about commuting at low speeds rather than being a speed demon. Say you're fully legal, and you're running at 250W. We'll say 10A to be mildly in your favour.

Peukert's Law is I^nT=C. We know C = 22Ah, We know you want to draw 10A, most lead acid batteries have an n of 1.2, so you'd get about 1.4 hours out of that battery.

Now, what if you wanted to build the same using Lipo? Well, Lipo has no Peukert effect. So to go for 1.4 hours at 10amps, you need 14Ah. So you need 6 of these:

http://www.hobbyking.com/hobbyking/store/__15521__Turnigy_5000mAh_4S1P_14_8v_20C_hardcase_pack.html

6 of those will give you a 24v, 15Ah battery at 6.6lb and will set you back about $144.

So on face value, it's a fairly line ball call. But you need to consider:

1. The effect of 22lbs on your bike in terms of efficiency and handling
2. The cost of shipping Lead Acid
3. The life of the battery - LiPo lasts more cycles than Lead Acid, but has a shorter shelf life if not refrigerated
4. If you're using more than 250W, then you can see the n=1.2 is going to kill your battery fast. For example at 500w, you'd go from 84 minutes run time to just 36.

Your call. I've gone LiPo and would never go back. But to each their own. If $34 (if that) is worth the extra weight and lower performance to you, go for it.

 

[fechter]

Lead is not quite dead, for some applications.

As far as comparing different lead-acid batteries, yes there can be a big difference at high discharge rates.
The kind to look for are "absorbed glass mat" and avoid the gelled electrolyte types. Most UPS batteries are the good kind. I've had good results with Enersys batteries. I get old ones for free, so can't complain about long term cost.

They still suck though.

As Ykick points out too, the actual capacity you get is a fraction of the rating at normal bike/scooter rates. Using a larger capacity will also give you a larger percentage of the rating, so bigger is better.... except for weight.

 

[latecurtis]

Sunder thosr 5000s in series exceed the 24 volt controllers capacity I was told they wont work on my newer currie. the 6s 8000 lipo by hobby king at 22,2 volt will work at over $100 and will need 3 to get 24 Ah. are you saying that Ah is not the same with lead acid compared to lipo. all I know from my studies is that lipo is lighter,a lot more money two or three times as much per Ah as lead acid, and also a fire hazzard. lead ass batteries dont get you the Ah that are rated either as i learned with the original currie battery pack. they weigh way too much and dont last long. I think both kinds of batteries suck.
is there any other types of battery alternitives. I am looking for a happy medium. and good range.

 

[Sunder]

Sunder thosr 5000s in series exceed the 24 volt controllers capacity I was told they wont work on my newer currie. the 6s 8000 lipo by hobby king at 22,2 volt will work at over $100 and will need 3 to get 24 Ah. are you saying that Ah is not the same with lead acid compared to lipo. all I know from my studies is that lipo is lighter,a lot more money two or three times as much per Ah as lead acid, and also a fire hazzard. lead ass batteries dont get you the Ah that are rated either as i learned with the original currie battery pack. they weigh way too much and dont last long. I think both kinds of batteries suck.
is there any other types of battery alternitives. I am looking for a happy medium. and good range.

8S = 33.6v hot off the press. Some 24v controllers will support that, some won't. If you're competent at soldering, you can disassemble those packs to make your own 6S packs for a lot cheaper.

Ah are not the same between LiPo and Lead Acid. You will get a lot more mileage out of an Ah from LiPo than you will Lead Acid. If you decided to upgrade to a 1kw motor in the future for example, your lead acid will only drive you 15 minutes. You'd only need 10Ah of 24v Lipo to get you 15 minutes at 1kw.

 

[parabellum]

I am looking for a happy medium. and good range.

http://www.pingbattery.com/servlet/the-24V-LiFePO4-Battery-Packs/Categories
http://em3ev.com/store/index.php?route=product/category&path=35 (i think cellman can configure the specs to your needs)

 

[dogman dan]

If you do go with the RC batteries, 6s or at most 7s will work for 24v. If you go with lifepo4, then use 8s.

Lead is not dead, but you do need to have a fairly short ride, so you can never discharge them deep which ruins them.

 

[Tommy L]

My guess is that you will be frustrated with Lead Acid.

I have not tried RC Lico cells yet from Hobby King.

But I do use LiFePO4 Lithium Ferrous Phosphate or Lithium Iron Phosphate chemistry.

Lots of cycle life. No sag if you know how to properly "size" the AH for the "C" draw.

I use the LiFePO4 on 3 of my bicycles. 40v nominal 88v nominal and 144v nominal.
I also use them in my Lawn Tractor at 50v nominal

Tommy L sends.....

[youtube]ygu8bV423wU[/youtube]

 

[wineboyrider]

3 of those 6s zippy 8ah will probably cook your motor on your scooter, because the equivalent amount of sla would have sagged long before it delivered the same ah's. 7s lipo is perfwiect for the currie scooters. I used them on my ezip 450 and izip 650 for years. 6s lipo gives you a safe lvc (3.5i per cell if 21 v lvc ) f you let the kids ride em and 8s worked on them albeit with the wrong lvc of 21v which equals 2.1 v per cell (death for lipo)

 

[dogman dan]

So 8s won't fry the controller? He could then use the cheap 4s hardpacks, and go 8s for more zip.

A really long run can cook motors that were designed to run with lead, which would run dry at 10 miles. I had that problem with my first brushed bike hubmotors.

If you go with lead, just keep the distance short between recharges, and make sure you spend enough to get a type made for EV's. 20 bucks apiece would be the wrong kind. Don't buy cheap lawnmower starter batteries.

 

[The fingers]

If I replace my lead with lead, I might use these.
http://www.impactbattery.com/ub12150-f2-12v-15ah-upgrade-ub12120.html

 

[dogman dan]

That's the right type. Made for stuff like kids electric car toys. FWIW, that kind of a battery is about 60 bucks in the walmart toy section in my town right now.

Find a place very close to your house if you mail order. Shipping lead bricks is pricy.