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Does a Lead Acid Battery exist with 1C or 2C discharge rate

Posted: Dec 20 2016 12:20pm
by ElectronS
as the title suggest , i want a 72v or 48v (100A-to 200A) battery pack that i can safely continuously discharge at 1C or 2C , ( 200A ) for ME1004 or ME1003 motor ....

i know that Lifepo4 or lithium ion can do that , but they are expensive and i donot need the long cycle life ( 50 -100 cycles are enough )

It appears that even "trojan" batteries ( said to be the best and most expensive) donot state in their datasheet more than 0.2C ( 5 hour rate discharge )

is it even possible or available ??

thanks in advance for sharing you opinions and experience :)

Re: Does a Lead Acid Battery exist with 1C or 2C discharge r

Posted: Dec 20 2016 2:22pm
by MitchJi
Why would you want to do that?

You can buy good lithium for less. Check the links in my signature.

Re: Does a Lead Acid Battery exist with 1C or 2C discharge r

Posted: Dec 20 2016 2:50pm
by Punx0r
Pretty much any lead-acid battery will comfortably handle a 1 or 2C discharge. The peukert effect just means you'll get less energy out compared to the industry standard discharge rate of C/20 (0.05C).

Hawker made some excellent (for lead-acid) batteries that were rated for 100% DoD, 1hr recharge and up to 12C constant discharge. Expensive, though.

Re: Does a Lead Acid Battery exist with 1C or 2C discharge r

Posted: Dec 20 2016 3:30pm
by Chalo
I concur with Punx0r that while there are SLA batteries that will perform as you describe, they'll cost you more than lithium. I used Hawker Odyssey batteries a long time, but I would never consider using lead batteries for a vehicle anymore. You'll always wind up with some combination of excessive weight, poor performance, short cycle life, and/or high specific cost.

Re: Does a Lead Acid Battery exist with 1C or 2C discharge r

Posted: Dec 20 2016 5:53pm
by Voltron
Not that you should go lead acid, but they can withstand a high c rate. They won't deliver anywhere near the rated capacity at that rate, but it won't damage them.

Re: Does a Lead Acid Battery exist with 1C or 2C discharge r

Posted: Dec 21 2016 3:25am
by DVDRW
You get about half rated capacity at 1C
UPS SLA lasts ~200 cycles.

Re: Does a Lead Acid Battery exist with 1C or 2C discharge r

Posted: Dec 23 2016 2:47pm
by ElectronS
thanks for the input guys , this was really helpful , and i have also received a recommendation for optima batteries , if anyone is also interested

http://www.robotmarketplace.com/products/optima.html

Re: Does a Lead Acid Battery exist with 1C or 2C discharge r

Posted: Dec 23 2016 6:49pm
by drewjet
The yellow top Optimas are very good batteries

Re: Does a Lead Acid Battery exist with 1C or 2C discharge r

Posted: Dec 24 2016 10:21pm
by 999zip999
That's $1,000 for 48v 1,500 for 72v. Do you need the weight of lead ?

Re: Does a Lead Acid Battery exist with 1C or 2C discharge r

Posted: Dec 25 2016 1:04am
by Hillhater
drewjet wrote:The yellow top Optimas are very good batteries
...compared to other lead batteries...
But they are still big, heavy , capacity rated at only 1/20 C, and have limited cycle life.

Re: Does a Lead Acid Battery exist with 1C or 2C discharge r

Posted: Dec 25 2016 5:16am
by ElectronS
999zip999 wrote:That's $1,000 for 48v 1,500 for 72v. Do you need the weight of lead ?
No offcourse , any weight saving is a plus for sure . but i was just naming another good quality lead acid that i found , if someone would want it for general use.

As for me i am back considering lithium , searching for cheapest , simplest (No BMS) ... :lol:

Re: Does a Lead Acid Battery exist with 1C or 2C discharge r

Posted: Dec 25 2016 6:37am
by dogman dan
100 ah of lithium won't be cheap either. But maybe you need only 50 ah? I'm just a bit confused what you need. You need 100 to 200 amps,, or amp hours?

Cheaper 36v 20 ah 18650 packs could have the bms's removed, then stack em up to be 72v 40 ah. Possibly as cheap as 300 each or so,, so $1200.

Not sure what 50 ah lifepo4 cells cost these days.

Figure 1c discharge rate continuous for cheaper stuff like that, and 2c burst, even though they will say more.

Re: Does a Lead Acid Battery exist with 1C or 2C discharge r

Posted: Dec 25 2016 10:37am
by 999zip999
The battery starting to look at is Westart. I know very little about them but look exciting. http://www.szwestart.com/ProductView.asp?ID=1065. I'm looking atthe 20ah grephene cell if I can get it to fit my bike ?

Re: Does a Lead Acid Battery exist with 1C or 2C discharge r

Posted: Dec 25 2016 11:42am
by ElectronS
999zip999 wrote:The battery starting to look at is Westart. I know very little about them but look exciting. http://www.szwestart.com/ProductView.asp?ID=1065. I'm looking atthe 20ah grephene cell if I ca get it to fit ?
wow this look HOT , i didnot know about this chemistry ... what is price of it ? lets say the 100AH cell ? how does it compare to LiFePO4 or LiFeMnPO4 in terms of price , and safety ( charge , discharge , BMS .... )

Re: Does a Lead Acid Battery exist with 1C or 2C discharge r

Posted: Dec 25 2016 11:57am
by 999zip999
I'm just trying to find information. I got a quote for 20 20ah grephene cells shipped $ 615.00 . They seam like A123 20ah big smaller and lighter. One aluminum one copper tab so can't be soldered. I would just use to bolt them together with blocks

Re: Does a Lead Acid Battery exist with 1C or 2C discharge r

Posted: Dec 25 2016 1:18pm
by 999zip999
Now you have me thinking again. I like big capacity cell. Ez to monitor ez to replace. 100ah is two hand fulls. The 20ah cell is 4.75in wide barley fit between the crank.

Re: Does a Lead Acid Battery exist with 1C or 2C discharge r

Posted: Dec 25 2016 5:16pm
by Voltron
Just for some size perspective...

My old 72v 12ah pack, that probably delivered about 5ah at the c rate I was working it at, and if you didn't catch it hot off the charger it was noticeably weaker than at float charge.
old lead.jpg
old lead.jpg (26.21 KiB) Viewed 1949 times
This is a 72v 15ah, that you can actually use the ah, and that won't self discharge all the time.
new battery1.jpg
new battery1.jpg (48.27 KiB) Viewed 1949 times
I'm strong, but just holding up one 3 battery 36v block of the lead acid was a chore. 2 was twice as bad obviously :) Re. simplicity, I run it without the BMS and just do occasional balance charging.
leadlithium.jpg
leadlithium.jpg (48.62 KiB) Viewed 1949 times
And trying to carry 40ah of lead acid just wouldn't happen.
triple.JPG
triple.JPG (106.67 KiB) Viewed 1945 times

Re: Does a Lead Acid Battery exist with 1C or 2C discharge r

Posted: Dec 25 2016 7:53pm
by Hillhater
I suggest you dont plan on riding that anywhere near a busy public place , sports event , etc that has a security alert around it . :shock:

Re: Does a Lead Acid Battery exist with 1C or 2C discharge r

Posted: Dec 25 2016 8:04pm
by Voltron
Or to the airport to catch a flight....

Seriously though... it almost never gets parked in public.

Re: Does a Lead Acid Battery exist with 1C or 2C discharge r

Posted: Dec 26 2016 11:06am
by Punx0r
Check out Nissan Leaf modules, they might do what you need and are good quality and simple to work with.

Re: Does a Lead Acid Battery exist with 1C or 2C discharge r

Posted: Dec 27 2016 7:43pm
by DrkAngel
See - ES Wiki Lipo vs SLA

Image

SLA can handle high sustained discharges but suffer severe inefficiency.
Capacity loss is relatable to heat production.

At 1.0C discharge: 10Ah LiPo (6lb) = ~30Ah SLA (75lb)
At 2.0C discharge: 10Ah LiPo (6lb) = ~40Ah SLA (100lb)

Re: Does a Lead Acid Battery exist with 1C or 2C discharge r

Posted: Dec 27 2016 7:55pm
by 999zip999
DrkAngle are trying to say something.?

LEAD IS DEAD !

WHAT ?

Re: Does a Lead Acid Battery exist with 1C or 2C discharge r

Posted: Dec 27 2016 8:11pm
by Ianhill
From what I read about how manufacturers go about stating the capacity of the stock 4.5ah or 7ah gel lead acids run of the mill batts is a test drain over a 24 hour period, so unless your running not much more than an led the stated capacity is never achievable, I see these types of batts as back up in commercial alarm systems and for this purpose they are well established, the cheapest option and have good reliability, But sometimes these types of cells are used in electric scooters etc that really don't suit them and they discharge like 2amp at best they slowly rise from the dead to give another amp or so they really can not gold the volts high underload, but there are lead acid traction battery's and these are a different story very powerful beasts but the weight alone makes these only viable for forklifts or dumper trucks steam rollers where a lot of weight is an added bonus, I don't think lithium forklifts will be around the corner for this very reason lead is king at being heavy ballast, the traction versions of lead acid are very cheap in comparison to the same output in volts capacity and discharge of lithium alternative's.
A forklifts battery's maybe upto 48 2.4v nominal cells in series with around 500ah and discharge around 200A max or close on 17kw where as a little ride on pump truck can still have up to 48 2.4v nominal cells in series but around 100ah and discharge around 80A max that's still nearly 7kw before a fuse blows so these batts maybe heavy and smell of eggs but a healthy batt will deliver good power, but it doesn't stop the fact the cells are much harder to keep in a healthy condition factory's abuse them run them flat leave them never top up with deionized water or run a desulfer mode on charger just fill it up with Gatorade and run it like they mobile flat as a pancake 3 years at vest and the cells toast where as a good owner will get 10years no probs.

Re: Does a Lead Acid Battery exist with 1C or 2C discharge r

Posted: Dec 28 2016 7:10am
by Alan B
Lead acid batteries designed for high C discharge rates are called starting batteries. They are optimized for high current but are not good for deep discharge.

Some Marine batteries are designed for starting and deep discharge which probably means they are not as good at either.

Starting batteries have large plate area for high current. Deep discharge batteries have thick plates for deep discharge. The two features are in opposition to each other. Using larger capacity batteries is the best way to get both at once by lowering the effective C rate for the desired current.

Re: Does a Lead Acid Battery exist with 1C or 2C discharge r

Posted: Dec 28 2016 5:41pm
by Hillhater
And none of them have a very impressive cycle life.
"Starter" batteries only see very shallow discharge/charge cycles, but still die after a few hundred cycles.
"Deep Cycle" batteries also suffer from limited cycles, even with optimum charge and maintenance protocols.