Best value 24v 100AH lithium battery?

poloman

10 mW
Joined
Apr 6, 2015
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33
Guys what's the best source to buy 24v 100AH lithium batteries?
Per recommendations on this forum messaged sun-thing28 and hunk-801 on ebay. Any other sources?
 
Just hit some suppliers for the quotes.
Was asked for [continuous current] and [peak current] by one manufacture.
Another asked for [charge] and [discharge] currents of battery.

How do i calculate those?
 
Well, if you're using that controller at full power then your peak current draw will be 200 or 225A, which in terms of "C-rate" on a 100Ah batter is 200/100 = 2C, or 225/100 = 2.25C

That's pretty gentle, but as much as some low-discharge LiFePO4 cells can manage without shortening their life considerable.

Your continuous current is a different matter. Your controller spec should clearly state "maximum continuous current rating", so it's a mystery why it does not. However, you don't have to use a controller at its full rating, and you may find your continuous current usage is much lower. The best way is to measure it while cruising along, as you typically would. Otherwise, guess based on speed, weight and incline.

These are all discharge currents, by the way.

Charge current is simply the current put into the battery by the charger during recharging. This is pretty straightforward and should be printed on the label of your charger. It may well only be something like 5A.
 
I'd look at some ev car supply sites. I'm sure there are heaps in the US.
All the CALB, WInston, GBS prismatic LiFePO4 cells come in 100Ah sizes. I'm sure one of those suppliers could make up or at least supply the parts to put 8 cells in series.
 
Guys thank you for your replies.

Punx0r said:
Your continuous current is a different matter. Your controller spec should clearly state "maximum continuous current rating", so it's a mystery why it does not. However, you don't have to use a controller at its full rating, and you may find your continuous current usage is much lower. The best way is to measure it while cruising along, as you typically would. Otherwise, guess based on speed, weight and incline.
Made the measurements:
when ridding with low weight(standard) billboard the current is 15A
When ridding with most advanced one(it's heavier) - it's max 60A

Did i understand this right? :
[continuous current] = 15A
[peak current] = 60A
[charge] = charger amp ( in our case 6A)
[discharge] = 15A-60A

Hillhater said:
poloman said:
Guys what's the best source to buy 24v 100AH lithium batteries?
?
You do realise that a 100Ahr , 24v battery is going to weigh over 50 lbs ?
Sure, it's much better than 2 lead acid batteries = 136 lbs that we are using now :twisted:
 
I have a 24V 100Ah pack from Elite Power Solutions. Cells are good and they included steel bands for compression but the balance boards they include (datasheet here) are junk. Anything over 0.5A charging current and they'll still let individual cells overcharge as there's no communication with the charger or a way to interrupt it.
 
poloman said:
Did i understand this right? :
[continuous current] = 15A
[peak current] = 60A
[charge] = charger amp ( in our case 6A)
[discharge] = 15A-60A

Correct :)
 
Guys what about the type of battery/cells?
Total newbie here. I see Lipo, LiFePO4, NCM, NCA, 18650?

Whats the cheapest battery type per mile?

Battery size - doesn't matter
Battery weight - doesn't matter (as long as it's not as heavy as lead acid batteries)
[continuous current] = 15A
[peak current] = 60A
Application - daily use in e-billboard bikes. 10am - 8pm pretty much not stop ridding, than charging batteries overnight.
 
poloman said:
Total newbie here. I see Lipo, LiFePO4, NCM, NCA, 18650?

Prepare to get confused.

Lipo refers to LiCO pouch cells, mostly in the RC toy market

NCM and NCA are different types of LiCO, each with different power/longevity properties. All LiCO is 3.7V nominal per cell

LiFePO4 is a different lithium chemistry, generally lower power, but safer and longer life. All LiFePO4 is 3.3V nominal per cell.

18650 is simply a style of battery: A metal can 18mm in diameter and 65mm long. You can get LiFePO4 in this format, but mostly it's LiCO.
 
You will hear many possibly battery options suggested here, but few of them are readily available, assembled and warranted,. Some won't even be safe ! ..others may need a lot of DIY input for assembly, fitting, or maintenance.
One solution that is available, USA supplier, and pretty foolproof, would be either 2 of the 12 volt , 100 Ahr units, from these guys...http://www.ev-propulsion.com/GBS-batteries.html
Not the lightest, not the cheapest, but they are available and reliable !
 
Punx0r said:
poloman said:
Did i understand this right? :
[continuous current] = 15A
[peak current] = 60A
[charge] = charger amp ( in our case 6A)
[discharge] = 15A-60A

Correct :)
Yesterday spoke to the guy in USA who sells Lithium batteries locally. (And all the time offering them to me)
When i said that i am ordering from China, he recommended to order lithium battery exactly with 200amp BMS or it will burn when used in my set-up.

Not sure he is right? (though it also says 200amp peak on controller)

Should i tell battery manufacture the peak current 60A, or 200A like this guy is saying?
And what effect does it have? Can having 200A BMS damage battery when used in my set-up?
Price wise seems like there is no difference between 60A BMS and 200A BMS.
 
Ok let's see a picture of the bike. What is your terrain. These is very important. Hills ?
With a controller like that it depends how you ride. What motor is it powering ?
 
999zip999 said:
Ok let's see a picture of the bike. What is your terrain. These is very important. Hills ?
no major hills, pretty flat. Small hills here and there.
Weight with driver and lightest billboard is about 450lbs, weight with driver and heaviest billboard is about 950 lbs
999zip999 said:
With a controller like that it depends how you ride. What motor is it powering ?
This is the motor (1 horse power = 745 watts):
Riding:
Work shift from 10am to 8pm everyday. 20 min breaks every 2 hours(more frequent breaks with heaviest billboards). Charging overnight.
 
Also what about the cells size? Does it makes the difference in the life of the LiFePO4 battery? 10Ah, 20AH, 30AH ?
The manufacture is saying that he run out of 20A cells, and can do 30A cells for same price we negotiated.
Basically 24v 120 AH battery(using 30AH cells) for same price as 24v 100 AH(using 20AH cells)

Does it make the difference? Other than the size of the pack?
 
The cheapest batteries over the long haul would be used automotive modules from a full electric or hybrid car. I think some of the modules in a Chevy Volt pack are roughly equivalent to 24V packs. I've bought an awful lot of different batteries and slightly used have been the best deal.

If you're willing to put significant work into it, you could make a pack from laptop and other sorts of batteries obtained for free, and you'd learn lots of useful info about batteries during the process.
 
poloman said:
Also what about the cells size? Does it makes the difference in the life of the LiFePO4 battery? 10Ah, 20AH, 30AH ?
The manufacture is saying that he run out of 20A cells, and can do 30A cells for same price we negotiated.
Basically 24v 120 AH battery(using 30AH cells) for same price as 24v 100 AH(using 20AH cells)

Does it make the difference? Other than the size of the pack?
Is he talking about cells rated for 30A current draw or 30Ah per cell? If the latter, then no difference other than the physical size of the pack. You can always go up in capacity as long as the size/weight is not a problem. Be cautious with chinese sellers, especially ones you find on sites like alibaba and ebay. Not to say they can't be honest, but there are a lot of them selling second hand, counterfeit, or used batteries as new and you'll have little recourse if you get junk.

I'd suggest getting something like hillhater suggested, a 100Ah/24V LiFePO4 pack with BMS and charger included. For your use (relatively low current) you'll be hard pressed to tell the difference between most brands of battery. If your goal is the cheapest solution, then piecing a pack together with used automotive cells would be a good option, but only if cost of your time is not a factor. Also worth mentioning is that if you were using a 24V 100Ah lead acid battery, you'll get more useable capacity out of a lithium pack with the same rating.

How many packs are you looking to buy?
 
dmwahl said:
Does it make the difference? Other than the size of the pack?
Is he talking about cells rated for 30A current draw or 30Ah per cell? If the latter, then no difference other than the physical size of the pack. You can always go up in capacity as long as the size/weight is not a problem. Be cautious with chinese sellers, especially ones you find on sites like alibaba and ebay. Not to say they can't be honest, but there are a lot of them selling second hand, counterfeit, or used batteries as new and you'll have little recourse if you get junk.
It was second. 20Ah/30Ah per cell.
I was just surprised that they have same price for 120ah as for 100ah.
I was about to order from them, but than luckily i decided to search endless-sphere.com for feedback on the company. And 'NO' - Vickpower not getting my business;)

dmwahl said:
How many packs are you looking to buy?
Planning to start test with 1 to find best supplier. And than will need about 30 batteries. At the moment talking to 2 suppliers. One of them is highly recommended here.
 
John in CR said:
The cheapest batteries over the long haul would be used automotive modules from a full electric or hybrid car. I think some of the modules in a Chevy Volt pack are roughly equivalent to 24V packs. I've bought an awful lot of different batteries and slightly used have been the best deal..


+1. Get used OEM EV cells for your application.
 
John in CR said:
The cheapest batteries over the long haul would be used automotive modules from a full electric or hybrid car. I think some of the modules in a Chevy Volt pack are roughly equivalent to 24V packs. I've bought an awful lot of different batteries and slightly used have been the best deal.
John in CR how much 24v 100ah pack will cost approximately made from these batteries, and where can i find them? Tried google search no luck.

Meanwhile talking to manufactures. They offered 2 options - pack made from A123 cells and pack made from 32700 cells. 2nd one is much cheaper.
 
Used auto modules are the cheapest, because you have to source components and assemble them yourself.
You will need to understand what to do.... ( and what not to do ) .. And learn how to test cells, make enclosures, balance packs etc.
Is that in your skill set, or do you have the time to learn ?
 
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