Best battery for the money?

I've been reading as fast as I can, and haven't found my answer yet, so I'll ask directly.
what is the best battery for the money? I have a brand new 36 volt Phoenix cruser motor, and controler, but I skiped out on ordering the lead acid battery partly because mailing lead seems like a silly idea, and because putting lead on a bike seams like a silly idea, so in order to fill the battery shaped void in my new electric bike I ordered up 30 1.2v 10AH "D" cell batteries, I should have realized that someone was streaching the truth with the 10AH rating, as after about 8 miles my no load voltage was around 28 volts and it no longer had any useable power, so here I am out about $200 in batterys and copper to make tubes for them that turned in to a nice rack and it's mostly only good for short trips, and that would be ok if I didn't live at the top of a steep hill.
I was just about to buy the Hi-Power Polymer Li-Ion 10AH 37 volt battery, untill I read Reid Welch's exprince with it, and that really put me off, and so I'm left wondering if I should start saving up pay checks for the 16AH Hi-Power Polymer Li-Ion or stay away from that as well?
any help with this would be great.

Your power consumption is not that far off, and you might consider going to 48v and adding another pack of 10Ah cells. How many amps are you drawing from the D cells?

Ryland said:

I've been reading as fast as I can, and haven't found my answer yet, so I'll ask directly.
what is the best battery for the money? I have a brand new 36 volt Phoenix cruser motor, and controler, but I skiped out on ordering the lead acid battery partly because mailing lead seems like a silly idea, and because putting lead on a bike seams like a silly idea, so in order to fill the battery shaped void in my new electric bike I ordered up 30 1.2v 10AH "D" cell batteries, I should have realized that someone was streaching the truth with the 10AH rating, as after about 8 miles my no load voltage was around 28 volts and it no longer had any useable power, so here I am out about $200 in batterys and copper to make tubes for them that turned in to a nice rack and it's mostly only good for short trips, and that would be ok if I didn't live at the top of a steep hill.
I was just about to buy the Hi-Power Polymer Li-Ion 10AH 37 volt battery, untill I read Reid Welch's exprince with it, and that really put me off, and so I'm left wondering if I should start saving up pay checks for the 16AH Hi-Power Polymer Li-Ion or stay away from that as well?
any help with this would be great.

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Don't know if the Phoenix cruiser motor is a 500 series or not, but if it is
it should be renamed the Amp Sucker Motor instead of Cruiser. And speaking of Reid Welch what ever happened to that guy? Did the bad battery experience turn him off from electric bikes for good?

The X5 hub motors aren't particularily well suited for low power outputs, or low voltages. 48v is the absolute minimum I would run on one, and 72v/40A is getting into the range the motor works best in.

The Cruiser is the 5304.

I agree with Lowell, and note in response to InstantKarma that most systems are going to burn roughly 1 ah per mile under no-pedal, flatland riding at 36 - 48 volts. In stock form, my Currie only gets 8 miles of no-pedal flatland riding with it's 24 volt 12 ah SLA pack.

If you have the 72 volt controller, I'd extend the string to 40-60 cells. For the same speed, current draw will drop proportionately, and you'll get proportionately more range, and your 5304 (I have the same model) will accelerate much better -- it's takes at least 48 volts and 35 amps to get the 25lb hubmotor rolling at a decent clip.

If you have the 36 volt controller, if I remember correctly it's OK at 48 volts (40 cells). You could run two parallel strings of 40 10ah NiMH cells with either a schottky diode or a SPST switch between them so they can be charged separately, or you can parallel a lithium pack of corresponding voltage (37v), or add ten more NiMH in series and then parallel a 48v lithium pack. Or you could add a 12 volt lithium pack in series with your 30-cell NiMH pack....etc, etc...many permutations and options.

with my current battery set up I noticed it jump up to around 25 amps while going up hill, with the voltage droping to 26-28 volts, going on flat it seems to draw around 12-16 amp at around 32 volts, normal voltage fresh off the charger is around 40-42 volts, after about two minuts of use it leavles out toa no load voltage of around 36 volts.
I picked the 36 volt controler because it seemed like a more user friendly battery to find and deal with, and I don't need to go fast, 20-25mph is plenty for me, I mostly want to use this bike to get over some rolling hills on a 4 mile trip to work, but as it is with the hills my battery wouldn't make a single round trip, and I can aford to spend a bit on a new battery, I just want to make sure that it will work so I'm not stuck with a 2nd defunked battery, altho I was thinking about spliting apart my "D" cell pack, and making a 12 volt pack for either the electric push lawn mower, or my ZAP bike kit so I could sell it more easly.

0.9V/cell under load is really pushing it. Sounds like if you double up on your Ah capacity you could run the cells around 1.1V/cell on the hills which is fine. Your range should more than double since you'll be wasting less power heating up the batteries.

I just wanted to tell you why I like my lead acid batteries. First of all they're sealed AGM batteries. I'm using three of these:

http://ebatteriestogo.com/merchant2/merchant.mvc?Screen=PROD&Product_Code=D5745-AB

I'm using a scooter, and I know that it would be hard to fit these battereies on a bicycle, but I'm very happy with them. I ride my scooter 10 miles, and when I return they're still ABOVE 36 volts. I haven't been able to come close to draining them.

I know SLAs have a high weight/power ratio, compared to exotic batteries, but one thing they do reaally well is DELIVER the power as quickly as you need it.

While lithium batteries are obviously very attractive, they will have great problems if you try to drain them too fast. Aparently, they can even catch fire. the Solar BBQ guy wrote this:

http://www.users.bigpond.com/solarbbq/lithiums.htm

Continuous discharge rate: 10amps
(I've tested these batteries at well over 20amps without any problems, though in the long term using continuously at high discharge rates will most likely effect the longevity of the batteries)

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You'd never run into those problems with SLAs

Eventually, I may consider using 4 of these:
http://www.batteryspace.com/index.asp?PageAction=VIEWPROD&ProdID=2457

Which would be awesome, but would cost $1700. My SLAs cost $100.

Also, notice that they say "maximum discharge rate=16.8 amps" And you have to hope their claims are true.

I hate to say it, but somthing can be learned from xters bike:

http://endless-sphere.com/forums/viewtopic.php?t=147&start=0

Notice how much current it takes to maintain different speeds on level ground:

2 amps = 12 mph
5 amps = 20 mph
10 amps = 26 mph
20 amps = 32 mph

However, he's using a 80+ volt system (notice his batteries! )

For a 48v system the current would be something like:
3.5 aamps = 12 mph
8.5 amps = 20 mph
18 amps = 26 mph
37 amps = 32 mph

It would cost a lot to get lithium batteries to deliver those kinds of currents.

One option you have is to use smaller batteries, and sacrifice a bit of range. I know I could get by with smaller batteries.

I'm not an expert, but from what I've heard it seems like the hub you have might be too big for a normal battery situation. It may need a supercharged battery setup like xters. If you're in a situation where you need huge amounts of power, loading your bike down with lead may not be practical. You may have to make a drag racer out of it.

But the geniuses around here know better than me.

I'm using a scooter, and I know that it would be hard to fit these battereies on a bicycle, but I'm very happy with them. I ride my scooter 10 miles, and when I return they're still ABOVE 36 volts. I haven't been able to come close to draining them.

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In my experience, SLA's are pretty much spent by the time they reach 12 volts each -- from 12.0 volts, a few miles left to get home if you're lucky. And the voltage begins sagging something embarrassing after only a few minutes. I tried 48v, 4 x 10ah SLAs on my x5 ebike while I was spending weeks soldering lithium batteries. I'm glad I spent weeks soldering lithium batteries.

I know SLAs have a high weight/power ratio, compared to exotic batteries, but one thing they do reaally well is DELIVER the power as quickly as you need it.

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That's true. But so do the second generation lithiums -- the a123's (LiFePO4 "lithium iron phosphate") and the emoli's (LiMN "lithium manganese"). The former is good for 30C, the latter for 15C -- similar power density to SLA's I believe, but of course a lot more expensive...but they last a heck of a lot longer than SLAs too. Which brings up another point. Replacing SLA's every year gets expensive! We've done the figures on few times in various threads -- for those who ride more than 3 or 4 times per week, the cost of lithium over the long haul isn't much different from SLA at all.
High rate lithium polymer (li-poly) is also in that range of 15-30C power density.

While lithium batteries are obviously very attractive, they will have great problems if you try to drain them too fast. Aparently, they can even catch fire.

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True. But out of three hundred and twenty five, I've only melted and ruptured two -- but there was no fire and it was my fault for running them down too low!
Out of the millions or billions on the market, lithium batteries have an excellent safety history when used within spec (which can be hard for some of us...)

You'd never run into those problems with SLAs

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Not per se. But shorting SLAs, as I've done, often has the effect of welding whatever is nearby while sparking like fourth-of-july fireworks. In other words, not idiot-proof either.

I hate to say it, but somthing can be learned from xters bike

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What's that supposed to mean!?
Just cuz she's ugly don't mean she don't ride sweeeet.

I'm not an expert, but from what I've heard it seems like the hub you have might be too big for a normal battery situation. It may need a supercharged battery setup like xters.

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The big motors are more efficient, not less. They don't require more power and they don't eat more electricity than small motors -- quite the opposite in general riding. What happens with big hubmotors and big battery packs is:

a) there's a tendency, particularly among folks like us, to want to get "all our money's worth" from our system, test the boundaries, etc. Big motors can sustain much higher power, so we tend to feed it more by increasing voltage, doing high-amp controller mods, etc.

b) with big power on tap, there's also a tendency to begin riding the ebike more like a motorcycle -- just ask Lowell.

c)It does take more power for the first couple seconds to overcome the inertia (get it rolling) of a 25lb hubmotor (like the x5) versus a 12lb or 8lb hubmotor (like the 4xx series or the BMC/Puma).
On whole and as can be appreciated by the hubmotor simulator:
http://www.ebikes.ca/simulator/
this loss is usually more than made up for by the big motor's better cruising efficiency. But those of us who like accelerating quickly must pay to ride, by likewise up-scaling battery performance.

xyster said:

In my experience, SLA's are pretty much spent by the time they reach 12 volts each -- from 12.0 volts, a few miles left to get home if you're lucky.

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That's good to know! I guess I have to postphone my trip to Tijuana.

I'm going to have to push the limits and report back.

All batteries, regardless of chemistry, SLA, Nicad Nimh, Lithium-x , suffer a faster death if pushed hard.. or beyond their expected parameters.

I have personally tried them all at this point, i have a considerable battery collection !

SLA - 4 x 12v 12ah
NiCad - 2 x 24v 8ah and 3 x 36v 8ah
Nimh - 2 x 36v 8ah
LiMn - 2 x 36v 20ah

One ride on Lithium.. and you won't ever go back !

SLA has the upper hand at high amp loads over Nickel batteries, in terms fo voltage sag, but suffer capacity loss at these rates.

Nickel suffers Self-Discharge

Lithium eats at your wallet pretty hard on purchase, but performs so well it makes you feel alot better after a ride !

Well I think there a pretty good battery for the money but I don't live in hills. Here's some info from an SLA battery test I did.

I did a full throttle run about a month ago. I had my newly installed voltmeter gauge. I was expecting more voltage sag because everyone says sla's suck. Anyway, its like this:

Voltage at start: 45.5 volt resting. (42 volt sla's)

Under full throttle at beginning - 42.5 volts
After 12 miles full - 40.0
After 15.5 miles full - 36
(1/2 throttle now)
Stop 16.5 miles - 35

There was a couple of lights I had to stop for along the way but it was wide open for most of the way at 20-21 mph. So, I'd say the performance drops off around 11.4 volts for each 12 volt battery under full throttle, being I have 3.5 batteries. I know this will look like a joke when compared to Lipo's, but it only dropped 2.5 volts for 3/4 of the ride which seems quite good for cheap sla batteries. This test was done in flat terrain which makes a difference I'm sure. (less voltage drop)

I was interested in Nicads but only "ebikes" has them in the larger size and no one seems to have them in the US. At least for the higher current ones.