Continuous Discharge

[englishwl]

How important is the spec on lithium data sheets called "continuous Discharge"? I am new to this, but it seems to me that would be really important just after Ah. I see a range on 48v batteries from 100A (RoyPow) to 175A (Eco) Any help would be apperciated.

[MoJeffro]

Typically both the AH and continuous discharge match. Well, at least with the lithium cells. I hadn't noticed previously that the Eco battery was off from that value. They even show the 72ah battery with 150 a continuous discharge. I'd be curious to find out myself.

[Tom47]

The 48 volt, 72Ah Eco Battery has the following corrected specs from an email I received:

BTW, ampere hours and continuous operating amps are not the same. The AH will tell you how long you could run at the continuous amp rate.

[englishwl]

Ok thanks. Do you think there is a big difference in power going from 100 to 175? RoyPow "power" model shows 150 and Big Battery is at 130. Eco is the only one listed at 175, but it seems they are hard to get right now. I tried 3 of the distributers listed on their website and they don't have them. I emailed the website directly a week ago and still no reply.

[Tom47]

Originally Posted by englishwl

Ok thanks. Do you think there is a big difference in power going from 100 to 175? RoyPow "power" model shows 150 and Big Battery is at 130. Eco is the only one listed at 175, but it seems they are hard to get right now. I tried 3 of the distributers listed on their website and they don't have them. I emailed the website directly a week ago and still no reply.

EB told me they should have their supply chain going smooth within a few weeks.

As far as a difference, in normal operation, fairly flat ground, amp draw shouldn't be an issue. I have never seen more than 94 amps on mine going flat out from a dead stop to 26mph with 4 riders, at which point it leveled of around 50 amps.

The ampere hour rating will decide how many hours you can ride at a certain amp draw. If I kept mine at 94 amps for 45 minutes, the battery would be dead or nearly so.

[englishwl]

Just ordered an Eco. Should be here in a week or so.

[DaveTM]

Originally Posted by Tom47

EB told me they should have their supply chain going smooth within a few weeks.

As far as a difference, in normal operation, fairly flat ground, amp draw shouldn't be an issue. I have never seen more than 94 amps on mine going flat out from a dead stop to 26mph with 4 riders, at which point it leveled of around 50 amps.

The ampere hour rating will decide how many hours you can ride at a certain amp draw. If I kept mine at 94 amps for 45 minutes, the battery would be dead or nearly so.

Must be pretty flat where you live\drive. Here in Pennsylvania where hills are hills and mountains are mountains, it takes some pretty good amp draws to climb some short steep hills and some longer "mountain" type hills. As you can see from this snippet of my controller data, for about 1 second (which is short or long depending upon what's going on) my cart draw was maxed at 392AMPS. I do go up the hill though!!

[Pat911]

Originally Posted by englishwl

How important is the spec on lithium data sheets called "continuous Discharge"? I am new to this, but it seems to me that would be really important just after Ah.

Continuous discharge is very important. Actually one of the most important parameters, more so than Ah, not less so.

Originally Posted by MoJeffro

Typically both the AH and continuous discharge match. Well, at least with the lithium cells.

Up until recently this has been the case with LiFePO4 batteries but as the cells improve, the discharge current has been increasing compared to the capacity rating.

The relationship between capacity (Ah) and continuous current rating (A) is known as the “C rating”. A 1C rating is fairly common for cheap cells. Better (read more expensive) cells may have a 3C or even 5C rating. A 100Ah 5C battery can discharge at 500A continuously.

Cheers
Pat.

[englishwl]

Thanks. That makes sense.

[Volt_Ampere]

Battery current is what matters for max current draw. Motor and battery current are not the same on your chart.