Lithium ion EGO 56v pack vs LiFePo4 at 30 amps

CarlRich

1 mW
Joined
Dec 20, 2016
Messages
16
I have a couple of go karts and Razor mx600 bikes ive Moses to 1800 w motors, controllers and LiFePo4 A123 AHR32113 ultra B cells 4500mah each. These big cells are capable of 100 amp discharge over and over and 6c charge rate. The 30 amps we intermittently throw at them while riding is nothing and won’t even warm them up. Downside is one side is aluminum and that’s hard to spot weld to. They are used at $10 each but test each for capacity they have all been excellent.
New to me is the EGO 56v lawn tools. I have a mower with a 7.5A pack. Fully charged the LiFe a123 cells are 58.4 and the li ion EGO are 57.9 off the EGO charger. The a123 I can charge at 6A for quick recharge. The new ego pack will charge in one hour. The cells are Samsung 20A capable 2500mah packs. I tested on several discharge levels and found the should be fine at up to 15 A intermittent use without over heating. 12.5A continuous increased temp 49F in 10min 5 seconds. Starting voltage not full but 4.06v and cut off set at 2.9v to preserve the cell.
The 7.5A EGO pack has 14 cells in series 3 parallel so should easily handle the intermittent 30 A max my controller will allow and provide extended riding by increasing capacity from 4.5Ah to 7.5Ah. All in I have about $230 to build the A123 pack with bms, but no charger. An ego 7.5A pack sells new online for $290 no charger but increased capacity and lots of protection built in including a hard case. If buying an EGO leaf blower, mower or snow blower you can opt for the 7.5A ego pack for less than $200 increase and includes the 550 watt fast charger. Are there better deals out there on built 58v packs with 7.5a capacity or more? I need it to be 30 capable. Anyone know where I can get the ego pack for less than $290 or a sale on backpack leaf blower or snowblower with 7.5A pack?
I’ll be comparing the two later today on the bike on hills.
 
If the pics are on a windows computer, they can be easily resized in the program "paint".

I sometimes size them to be 700 pixels across to gill the page, and 600x400 is a good general purpose size.
 
Well I was able to test the A123 4.5Ah vs EGO 7.5Ah packs. The test is not terribly precise but as close as I could make and useful for my needs.

We charged both packs the night before then following afternoon rode with the A123 pack first up a long gentle slope to get the voltage once the dirt bike was at speed but going up a gentle slope. All testing off road in grassy park. This gave a baseline voltage under load. Then we did 10 consecutive bigger hill climbs at a steep slope followed by another run on the same gentle upward slope reading the voltage in the same location having given enough distance for the bike to reach speed yet still be under load to read voltage again. This process repeated over and over.

A123 pack EGO 7.5A
Starting voltage 56.8 57.3
initial run up gentle slope 49.25 51.4 These are both at 30amps full throttle
10th run up hill 49.1 50.6 All runs through out the test are hitting 30A, Hill runs stay there.
2nd run up gentle slope 48.65 49.3
10th run up hill again 48.1 48.1
3rd run up gentle slope 47.8 47.7
Amp hrs consumed 3.25 2.9
The A123 was not run further as it seemed enough to get the general idea. The EGO pack starts a little higher begins to drop off sooner than the A123 so the A123 has a flatter discharge where the EGO drops off slightly faster. The next day we ran the EGO pack further to find it's limits. There may be some loss of charge sitting overnight?

4th run up gentle slope 45.9
10th hill run 44.6
5th run up gentle slope 44.3v 4.6 Ahrs used up plus whatever lost over night
10 hill runs
6th run up gentle slope 42.0 6 Ah used up
I then ran 6 more hill runs to see how low it would go before either the battery or the controller would shut off the system
38.5v 6.9 Ah used up
within a few more hill runs it was running in the 37's for voltage so I stopped. I assumed the battery or the controller would shut the system off at 42v. It never kicked off. The bike's controller may look at starting voltage when plugged in and shut it off after a set percentage has dropped off or the setting is below 37v.
Conclusion; It looks like both will work fine. I will point out that I bought the A123s online used. How used? Can't say. I've run them for a year since buying (25 cycles tops) versus the EGO having maybe a dozen cycles thru the lawn mower. The two perform similarly overall with the EGO being slightly higher at start and slightly lower by 3Ah used. The EGO pack kept doing quite well up to about 6.8 Ah used then was dropping off quickly for hill climbs. Probably would not have been noticeable on the flatter areas or up the gentle slope. Best of all I kept watch over the pack on the charger and in just under 1 hour the EGO pack was fully charged. The A123 has a faster charger so it was ready in 45 minutes or less but if we had 7Ah used from the EGO pack after the short ride home then the charger must run at 7 Amps or possibly higher initially then slowing at the end for balance charging. The charger is said to be 550W so 550W divided by 58v would be 9.8 amps. Interesting stuff. I'm going to get a 2nd 7.5Ah Ego pack to run in parallel on my kids twin 1800 watt motor go kart. Hopefully they play nice in parallel when directly wired as opposed to going through the provided ports with the data link.
 
CarlRich said:
LiFePo4 A123 AHR32113 ultra B cells 4500mah each. These big cells are capable of 100 amp discharge over and over and 6c charge rate. The 30 amps we intermittently throw at them while riding is nothing and won’t even warm them up. Downside is one side is aluminum and that’s hard to spot weld to. They are used at $10 each but test each for capacity they have all been excellent.

Where did you get your A123 AHR32113 ultra B ?
 
https://www.ebay.com/itm/Brand-New-A123-AHR32113-32113-4500mah-3-2v-High-Power-Lifepo4-Battery/263464543734?hash=item3d57b5e5f6:g:kIIAAOSw~AVYqnFF
 
Or you could use these instead: https://www.ebay.com/itm/Brand-New-A123-AHR32113-32113-4500mah-3-2v-High-Power-Lifepo4-Battery/113276833104?_trkparms=aid%3D222007%26algo%3DSIM.MBE%26ao%3D2%26asc%3D20160323102634%26meid%3Ddc3a5d129de5418bb88cce65c803fa8b%26pid%3D100623%26rk%3D1%26rkt%3D3%26sd%3D263464543734%26itm%3D113276833104&_trksid=p2047675.c100623.m-1

They have threaded posts on them. It would be easy to make a solderless pack.
 
If they were not $25 a piece I'd be all over them. I've just used a spot welder on high on the aluminum side and then put hot glue under the metal connecting strips between the cells to further help hold them in place so as not to stress the spot welds on the aluminum. Have 3 such 48v packs in kids off road dirt bikes/go karts. Tough to overlook the 7.5A EGO packs. I'm waiting on the backpack blower w/ 7.5Ah pack to go on sale so I'll have a 2nd one. I hope it snows like crazy this year so I can justify the snowblower with a pair of 7.5Ah packs. :D

http://eclipsebikes.com/product_info.php?products_id=9
Here you can get the A123s with threaded studs both ends, plastic caps with which to hold two together and connecting metal strips to create a pack for $20 US. Not sure what shipping would be but sure wish this deal were in the US. This is similar to the kits offered by Vruzend to build your own pack with the Li Ion cells. Great concept. Still seems money well spent to just get the EGO pack.
www.vruzend.com
 
Back
Top