UPP 48V 24AH Model: R049-6

Long story short someone tipped me off that some UPP batteries were causing fires.
I had already planned to tear down the battery and swap out the BMS so hearing this I immediately tore down the battery to inspect it.
I paid nearly $500 to get the best quality I could from Amazon.

This was my order.

I am very pleased to inform you that I am very happy with what I found inside it.
We need to do some engineering calculations for setting up my VESC Controller anyway so we will do that here now also.
Lets take a look at the United Pack Power specs.

So UPP rates the battery at 40Amps. It has a 40 amp BMS in it and that is why the battery is limited to 40A. Other limiting factor is the connector plug between the base and the battery. It probably can't support 80 or 100 amps because it'll get hot. That connector will get hot fast. Other than that it has 10GA 100C Leads. Which is really good for 40 amps I think. I wasnt gonna go where i am about to go yet but I think it's time. I can't get into the discussion of pushing more amps out of the battery without discussing everything that goes along with it.

I would say if you just want to ride and you really don't care about how or why things work then just stop here........ Know this is a very good battery and that's all you need to know.

For those of you who enjoy diving down the rabiit hole hold onto your hat. It's about to get slightly deep.
By trade I am a Mechanical / Manufacturing Engineer. When I design something I follow the principals I employ every day.
So let's do a little engineering here.

Ok so starting out with the factory R049-6 Battery we know we are limited to 40 Amps.
Most bikes seem to actually be running between 20 and 30 amps or lower. So the battery is designed to meet those needs. It matches the typical 20 to 30 amp controller. Thats why UPP is showing that the battery is good for 1500 watts. Thats the average maximum ebike draw out there.

So lets take a look at my situation. What are my specific needs, how much power can my controller demand? Well I will tell you it is far beyond 30 amps. It's actually 10 times that.
I Introduce to you the one controller that can satisfy my addiction to AMPS. This tiny little VESC outputs up to 300 Amps with proper cooling. And I have very good cooling so I could get that if my battery can feed enough power. I am so glad I bought this 2 weeks ago. They just got them in an they are gone already. But they'll make more.

What a beauty. God I am in love. Open Source Fully Programable Unlimited Power.

Ok so lets look at the Tronix 250R Specs.
Here is what were after you can find it on there page.
  • Up to 250 Phase amps peak (300 peak, cooling required)
  • Up to 120 Battery amps max
  • 8S - 24S Battery (up to 100.8V fully charged)

So back to the battery now we have the specifications we need. 120amps max draw from the battery. So best option would be to build a battery that can output even more than that so the VESC would never be limited.
I already spent 500 on the UPP battery so Option 2 is to figure out what can I get out of the Cells and then get a appropriate BMS or simply set the VESC to limit the draw from the battery. So technically I could use a BMS for charge only and then have Direct Output from the battery to the VESC. In my case I am going to get a Smart BMS. It is Bluetooth and configurable and just adds another layer of safety.

So lets move on to that situation. What size BMS do we want to buy. Well right off the bat I'm gonna buy a 120 AMP BMS. Why....well because even if my battery can't supply the current currently it would be nice if it could in the future. I don't plan on buying another VESC...I already got one of the best and realistically I shouldn't need anything bigger. However I do plan to build a battery so the possibility is there. So buy components that will support the upgrades you might want in the future and you won't be buying things twice.

The other thing is when you get to the 100A plus BMS it locates external from the battery and it also has a built in fan for cooling. It will be mounted with my VESC on the bottom of my rear battery rack which is actually a giant aluminum heatsink as well. For both of those.

So here's the BMS im figuring on.

Heres a bunch of photos of the battery. After that I'm gonna end this post for now.

But next we will calculate exactly how many amps we can get out of that pack max. I'm pretty sure it's close to 90 amps.
The VESC can run 100V. I wish I could connect 2 of these batteries in series but then Id be over 100 V if I did I would only have to pull 60 amps each max out of the 2 batteries to use the full potential of the VESC . I may do that anyway and just step down the voltage. If the buck converter can support 120 amps. But those can run in parallel and series to adjust voltage and amperage output. I wouldn't step down the 100+ V. What I would do is drop each 48 down to the closest I can get to that 100V.

Ahh on the other hand I might just try to run the 48s in series. I would be at 4.2V FULL CHARGE. X 14 CELLS = 58.8 Max Charge so 58.8x2 and that puts me at 117.6 V. Yea maybe pushing it a little but from the research I've done the engineer and builder of the TRONIX line underrate there product for a factor of safety. So now what is are max V. The caps give us a clue. So looking at the caps on the VESC there rated 130V. So they can take it and I can probably get away with it. What I gotta do is look at the VESC open source page where the schematics are available and trace through the high voltage circut and look up the specs for all the microprocessors in the circuit. Otherwise I could do it but if any component on the high voltage circuit cant take the voltage it's gonna smoke. O well.... It's something to ponder. It would be better to build a pack out of those cells big enough to handle 150 amps.

Check out the battery now. We will get more into the calculations tommorow.



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Now lets go ahead and move on with the battery.
Lets compare the 2 different lg cells.

LG INR21700M48F 21700 17.4Wh Li-ion Battery cells ---->> This is what's in the battery.

This is what was specked by UPP.
Lithium Ion INR21700 M50 18.20Wh

The pack is 13S 5P- Damm I lost some photos on my last post. Here are those specs from UPP.

So lets figure this out.

13S 5P =13 cells in series and 5 series packs in parallel. (Total 65 cells)
65*17.4 Wh = 1131 WH or 1.131KWH capacity
1131 wH / 54.6 = 20.71 AMP hours

So this means I din't get what I Paid for because it was supposed to be 24 AH.
LG INR21700M48F 21700 17.4Wh Li-ion Battery cells ---->> This is what's in the battery.

This is what was specked by UPP.
Lithium Ion INR21700 M50 18.20Wh
65*18.2 =1183WH
1183 / 54.6 = 21.666 AMP Hours

So i am a little confused here. This is more closer to 20AH than 24AH with either battery. Maybe that's nominal WH. Not max charge.

At any rate there is a positive spinoff. The battery that I got has a higher discharge rate and that suits my setup better anyway.
I got over 50 miles range on this at full throttle so im good with that.

So now back to our question. How many amps can we push from the battery with a direct connection? No BMS.
We can calculate that but first we need the real manufacturer specs and test report. I will post links for both batteries.

This one is supposed to be confidential.

More Math

2.5V*13 = 32.5 absolute cutoff voltage.

4.2V*13=54.6 standard charge. <<<----The amp hours above are calculated correct. So it's not 24AH.
That seems very misleading to me.

Alright back to amps. If we keep the battery under 80 degrees.
The max discharge is 13800ma. 13800*.001= 13.8 amps per cell.

In series we up the volts but maintain 13.8 amps. so 13s=54.6V @ 13.8 amps

Parallel connected groups of 13 cells = 13.8 Amps
5 sets of parallel packs = 13.8 x 5 = 69 Amps.

So there you have it. To get over 69 Amps with this cell we would need to add parallel packs to it.

I wouldn't recommend to pull more than 69 Amps out continuously. However we could have a peak output for 10 seconds of 80 watts at 80% State of charge.
They like to make it difficult. they could have given us that in amps. Now we got to calculate and convert.

80W at 3.63V = 22.038 amps per cell pack for 10 seconds. They rate at 80% SOC but this calc is at nominal.

22.038 x 5 = 79.997 amps Burst for 10 seconds.

So now we have the data needed to configure the BMS and the VESC.
I don't have the BMS Yet and I'm only working on a bench right now.
So I'm gonna run the 8GA Leads terminated with the QS8 Connector Directly to the battery output.

To do it this way safely we need the following settings in the VESC.

Config 13S 5P
Cells = 65
54.6 V Max
32.5 V Cutoff
I'm going to set 60A MAX AMPS. <<--leaves me a little buffer since I'm running Direct. 9 Amps
And 80 Amps for the PEAK Output.

Now with this exact battery UPP or another battery of the same LG Cell you can use these settings. Only for 13s 5p.

If you have a different battery or different cells follow my calculations and determine your own numbers.

Now lets get this VESC hooked up on the bench.
I have 100% confidence that with these settings no damage can be done to the battery.

Mannnnnn... I gotta go get some solder. I haven't even had coffee yet.
I did get most of the seatpost collar / battery rack holder machined. Still have a little more to do on it. Made out of a solid 6061 T6 aluminum


Here's how the battery makers figure Ah. You have 4.8Ah cells, five in parallel. That's 5x 4.8 or 24AH. This is a standard algorithm. Your pack is OK as far as AH..