Average lifespan of lead batteries

[blueb0ttle2]

Before you folks make the usual jabs at lead, how long would you say lead batteries are supposed to last? And what criteria would you use before going out and replacing them? One of the battery packs on my ezip is beginning to behave sluggish after 6 months of (almost) daily use, and range is ever so slightly diminished now. Did I get my money's worth out of the lead now? Am I justified to invest in a new battery? (Phew! Lots of questions! )
Also, how many years have you guys gotten out of ping batteries? I want to see if I can recoup my investment, since it's either $150 for all four 10AH lead acid batteries, or $350 worth of LiFePO4. I'd have to get ping to custom make the pack so it fits in my cases. If that is impractical, I might build my own pack out of Headways, and charge the cells individually with one of those hobby-king deals.
Thoughts?
Again, don't mock me for using lead, I am running on a tight budget and I still have my doubts about the long term benefits of Lithium.

 

[icecube57]

150 solid cycles if cared for properly... maybe.... with near full DOD on a bike.

But remember usable capacity at high C-rates is reduced.

12AH SLA is realy 7AH on a full discharge. To get this pack to last 300 cycles at 50% DOD you have to cut that in have to 3.5 to 4AH.

At top speed thats 3-6 miles.

12ah LIFE IS REALLY 12AH ON A FULL DISCHARGE. GET THE PACK TO LAST 1000-1500 CYCLES YOU HAVE TO STOP DISCHARGING AT 80%. THAT IS 9.6AH.

At top speed that 9 to 18 miles.

Also Lithium is 1/4-1/3 of the weight for the same capacity

You would have to buy SLA packs 10-15 times over the lifespan of a Li Fe pack.

You would have to buy 2.5x more lead to equal the same AH capacity as Li Fe.

That should be all you need to know between the two.

 

[blueb0ttle2]

I think I'm almost at 150 now. I expected twice as much!

Why have you deceived me, my old friend lead!

 

[icecube57]

I say 150 cause in the real world. Some stupid ass american will forget to plug it up or something and they go bad. Not from being over worked but from sulfation. In true cycling they may last a bit longer but the plates will start wearing down and you experience voltage sag and capacity reduction as you are experiencing now.

 

[blueb0ttle2]

I only forgot to charge once. Otherwise, charging them after use is a daily religious practice :wink: I think I run them at about 15 AMPS continuous, and (I must confess) I am more of the electric moped persuasion, so I only pedal when I need to. Also, I often start from a standstill. Which means that I am certainly pumping 35 AMPS out of them in spurts on a regular basis. Perhaps I did trash them
For the first few months I alternated between the two 10AH packs, then I put them together in the hope that this would put less load on each individual battery. Oh well!
Also, I traveled 8-12 miles a day on one charge.

 

[D-Man]

I've found that they last a long time. The thing is that the lifespan is not consistant for the cells inside the lead battery. One battery will remain strong and outlast the others while another will loose a cell premature. Have sensors on the batterys. Replace the weak one. Get another 100 cycles.

 

[blueb0ttle2]

I'm trying to save money.
[youtube]crARnAJv1EM[/youtube]
I guess ping might be the best buy after all, I'll have to sell the fridge to get 20AH worth of it though!

 

[dogman dan]

I prooved you can trash em in 50 cycles. But I'm a :lol: merican. 100% dod's did the trick. I had a pingbattery in shipping at the time, and simply didn't give a shit.

200 cycles seems reasonably possible to get with decent use pattern. I've heard of much more, but with cars that used a discharge pattern of less than 50% dod. Look up old Safe threads if they still exist for an extreme case of making the lead last.

 

[TylerDurden]

Look up old Safe threads if they still exist for an extreme case of making the lead last.

Not safe, "D-man"... he got ~5000mi off a set.
http://endless-sphere.com/forums/viewtopic.php?f=3&t=296&start=60

 

[slowlane]

I got 180 cycles from UB12150's AGM with a 36V 200W bike . Changed out pacs at 30-50% DOD . Cold weather use is finishing them off . Worked real good in the hot summer here last year . Isn't just the outside temp killing AGM , they need to be 90F+ to get 100% charge . My understanding is the plates outside edge / corners will sulfide if full charge is not reached with lead chemistry . I'm heating batts them charging , big difference in top end and duration than room temp charging . Smart chargers : also a difference when charging 2A or 4A ( 12V ).

 

[blueb0ttle2]

It turns out that I only had a faulty connector on the bike, the battery is probably ok.
This is the second time I've had to replace connectors on the ezip! I'm considering rigging something with Anderson connectors instead of those dinky spring clips.
Anyway, the end is near for the batteries anyway, so I guess either a pair of custom pings will be in order.

 

[blueb0ttle2]

I prooved you can trash em in 50 cycles. But I'm a :lol: merican. 100% dod's did the trick. I had a pingbattery in shipping at the time, and simply didn't give a shit.

200 cycles seems reasonably possible to get with decent use pattern. I've heard of much more, but with cars that used a discharge pattern of less than 50% dod. Look up old Safe threads if they still exist for an extreme case of making the lead last.

I'm 'MERIKAN too! Grrrrr. I feel the imperialist machismo pumping through my veins!
Seriously, I suppose I do mistreat my pack by running to 50% DOD every time. Especially since I sometimes don't pedal to start. If I had a way of changing the gear ratio, then it would be ok, and I am musing about that here.
I'm thinking of using some sort of jackshaft, and a free-wheeling crankset. The gear ratios in the jackshaft would have to be selected very carefully though. Might have to get some custom work done. Oh well, nuthin' that good ol' 'MERIKAN credit cards can solve, DAMMIT!

note: Obviously this contradicts my stinginess in previous posts, so I'm using irony, something that not many 'MERIKANS like me understand

 

[SamTexas]

... or $350 worth of LiFePO4...
Again, don't mock me for using lead, I am running on a tight budget and I still have my doubts about the long term benefits of Lithium.

Lithium is great as far as energy density is concerned, but not so great in care and maintenance. Don't forget to add the cost of a battery charger and a trusty BMS.

I'm against lead for ebike application, but I love lead for its simplicity in care and maintenance.

 

[D-Man]

... or $350 worth of LiFePO4...
Again, don't mock me for using lead, I am running on a tight budget and I still have my doubts about the long term benefits of Lithium.

Lithium is great as far as energy density is concerned, but not so great in care and maintenance. Don't forget to add the cost of a battery charger and a trusty BMS.

I'm against lead for ebike application, but I love lead for its simplicity in care and maintenance.

Don't forget the powersupply for the charger ( lipo ) and a ton of connectors, special crimping tool, lots of wires, battery discharge alarms, battery medics......$$$ Too many connectors plugging and unplugging every run = no fun.

 

[liveforphysics]

... or $350 worth of LiFePO4...
Again, don't mock me for using lead, I am running on a tight budget and I still have my doubts about the long term benefits of Lithium.

Lithium is great as far as energy density is concerned, but not so great in care and maintenance. Don't forget to add the cost of a battery charger and a trusty BMS.

I'm against lead for ebike application, but I love lead for its simplicity in care and maintenance.

Don't forget the powersupply for the charger ( lipo ) and a ton of connectors, special crimping tool, lots of wires, battery discharge alarms, battery medics......$$$ Too many connectors plugging and unplugging every run = no fun.

But, set your ish up right, and it's never anything to unplug, and 1 connector to plug-in when you're done with your ride. No RC charger needed either, just a properly setup meanwell (this is after you've balanced your packs and confirmed they all discharge/charge evenly together etc). Once you master LiPo, it's extremely simple to use.

 

[MikeFairbanks]

So, what are we supposed to do if the battery is fully charged, but we don't ride for a couple days? I just disconnect from the charger and leave the battery isolated (not plugged in to the controller). Is there anything else I should be doing or is that good enough?

 

[dumbass]

The term cycle is a loose term. A cycle could be 60% dead or 10% dead. Certainly you will get a whole lot more cycles running them only 10% and recharging. then 60% and recharging. OR waitting till the next day to recharge them. I have 3 packs 2+ years old but have no idea how many cycles are on them. They are normally lightly used.

I currently used ThunderSky lifepo4 packs and the added expence is well worth it. The added power is alone worth the added cost.

Bob

 

[RTLSHIP]

If you leave a fully charged SLA battery for a few days, it should only self-discharge a little. In 70 degrees temp, it takes about 5 seconds to get a green light on a charger. with hotter and colder temps it may take a 30 seconds or more to top off.
I have 3 sets of 36v 12ah SLA and they have worked well for over 2 years, but I only use each pack about 20 cycles per year.
The average trip is 4.5 miles to work and then recharge and ride home later.
I also have 48v lifepo4 packs for faster and farther riding.
Maybe about 250 cycles is reasonable on SLA's if you don' go below 12.25 volts and quickly recharge. I guess about 2000 miles per pack. After that, the pack is only zippy good for shorter trips.
bluebottle, with a 24v 10ah Ezip pack, you should probably only be going 3 or 4 miles tops, then recharge. the farther you go per trip, the less lifespan you'll get.

 

[blueb0ttle2]

bluebottle, with a 24v 10ah Ezip pack, you should probably only be going 3 or 4 miles tops, then recharge. the farther you go per trip, the less lifespan you'll get.

I run with a pair of them in parallel for 8-10 miles a day. Right now they are chilling out, since the cables in the battery case need to be replaced. I'm getting some exercise

 

[RTLSHIP]

that's not too far as long as you recharge soon

 

[bobc]

I work with a team in the Greenpower series of electric races for schools in UK. The rules of the formula are fairly simple - the organisers supply batteries and motors to ensure it's a level playing field
http://www.greenpower.co.uk
For the last few years the batteries have been car batteries (by Yuasa). To be successful we have bought a new set of batteries for the national final every year - these (car) batteries lose about 8% capacity on every full discharge, after a season, they're doorstops. Obviously we're racing - depth of discharge is always 100% (or more).
We found out lots about battery charging, management and care, just one of the factors helping us win things!
One dodge we learned was that both peukert and arrhenius apply - so if you heat the battery to 30degrees over ambient & keep it insulated - it 'thinks' you are discharging it 8 times more slowly yeilding a LOT more power due to peukert. That wrinkle gave us 40% more power in the 2009 season & race speeds that frightened Greenpower into changing the rules.....
Next year we have much smaller batteries of deep discharge SLA type. Tests to date suggest these have at least 4 times better cycle life than the Yuasas and a much smaller peukert coefficient.
(PS by looking after our batteries this year, we managed to win the finals without buying new)
The combination of peukert, arrhenius and internal resistance make lead acids particularly badly affected by low temperatures.

 

[grindz145]

If for some reason you have a bike that you want to last 10 plus years, but only discharge it 100 times or so, lead would be the way to go. You can't be lead for calendar life.

 

[dogman dan]

Yes you can. Nicads.

 

[grindz145]

Yes you can. Nicads.

Oh yeah? What's the calendar life on Nicads? I'm sure you're right.

 

[D-Man]

Not all nicads are created equal. Just saying nicad means nothing. Lots of different brands. They go belly up all the time. They hate to sit with voltage in them. Have weird performance like slowing down and speeding up during discharge as they get older. Cell reversal all the time. Who wants to have to cycle a battery just to keep it going. Like keeping a human body on life-support all the time. Lets see I want to ride my bike tomorrow so I'll have to cycle it 3 times today. :lol: