Victpower A123 pre-made pack review

[cwah]

I'll probably end the voltage at 3V or when the BMS cut-off. For now I've used 800wh and the voltage still was at 65V. I'm waiting for the strong voltage drop to stop. I believe the Lifepo4 are very on their nominal voltage, and when they are not anymore at that voltage, there isn't much power left. And it's time to stop

[cwah]

id say either no lower than 50 or 52v but it would be interesting to know what that BMS board uses

Yeah, also maybe 50V few time to check the pack capacity. But I wouldn't do it most of the time.

[cwah]

Tried a full charge today. On my cycle analyst the voltage went up to 73.2V, then go slowly down to 72.7V. On my multimeter I have 71.8V...

I almost have 1 V difference between my multimeter and the cycle analyst. Who's right?

[999zip999]

Do you have a second MM ?

[ohzee]

Just charged up one of my 20s A123 packs I made from victpower cells. It has a ping high power BMS which evens out all
the cells.. Testing all the cells they are at 3.47 pack voltage is 71.5.

So id say yours is looking good as well.

[cwah]

Did a capacity test today... and I'm quite impressed by my pack.

I did 66 km at around 35-40 kph, and a lot of start and stop. So a lot of acceleration.

I use it until 58V under load:


I noticed that under 61V, the pack voltage drop really quickly.


And on my cycle analyst, it says I used 1450wh


My cycle analyst is probably mis-calibrated, because it would otherwise mean that my pack has over 22AH capacity. I did 66 km at 35-40 kph with good acceleration, so my bike used at least 15 wh/km and my pack has at least 1000wh even if miscalibrated.

It was a bit warm after the ride, but I think I'm going to be happy with my pack.

[cwah]

Do you have a second MM ?

no, only 1 mm

[deVries]

Did a capacity test today... and I'm quite impressed by my pack.

I did 66 km at around 35-40 kph, and a lot of start and stop. So a lot of acceleration.

I use it until 58V under load:

I noticed that under 61V, the pack voltage drop really quickly.


And on my cycle analyst, it says I used 1450wh

My cycle analyst is probably mis-calibrated, because it would otherwise mean that my pack has over 22AH capacity. I did 66 km at 35-40 kph with good acceleration, so my bike used at least 15 wh/km and my pack has at least 1000wh even if miscalibrated.

It was a bit warm after the ride, but I think I'm going to be happy with my pack.

Do you have a way to measure temps on your pack? Where is the most heat generated? (Use a laser temp probe. )

What is your controller/motor setup? 20" wheels & tires used & inflation psi?

How did you calibrate your CA?

Thanks.

[cwah]

No, no way to measure temp on my pack yet. Waiting for the laser temp probe from HK that's never in stock.

I have a Lyen 84-132V controller with 16" wheel brompton

Inflation to 90-100 psi

I just use Rshunt value provided by Lyen for CA calibration.

------------------------------

Anyway, I also noticed that my pack went a little bit bigger. It cracked my polycarbonate box I created for it

I wouldn't say it would be due to abuse, maybe normal because it's a new pack?

[deVries]

Anyway, I also noticed that my pack went a little bit bigger. It cracked my polycarbonate box I created for it

I wouldn't say it would be due to abuse, maybe normal because it's a new pack?

With some heat involved with discharge there is bound to be some pack expansion. I think it would be hard to stress 20Ah packs on an eBike assuming good pack design for low resistance & low heat buildup.

Did it crack starting at a screw hole? Pic?

What motor are you using? No load rpm?

Thanks.

[cwah]

I used super glue for my polycarbonate box
Now it's fixed, didn't take a picture as the box wasn't glued that strongly anyway.

I'm using conhismotor mini hub, the no load RPM should be around 600 RPM at 66V and 525 RPM loaded, which is roughly 40 kph.

[docnjoj]

Superglue is really brittle and not a great choice for welding polycarbonate. There are Mek type industrial cements that really work well for acrilic and Lexan. I think one os called CtC-16 or Weldbond. I'll look it up.
otherDoc
Here you go. This is the stuff I used for my Lexan battery box. Weld-on
http://www.ridoutplastics.com/adandcem.html

[cwah]

The seller gave me some transparent glue, and it wasn't working that well. So I decided to go on industrial super glue. I've put a lot of this glue, and for now it's working quite well.

Will stick check you link and buy them if I need that later.

[deVries]

I'm using conhismotor mini hub, the no load RPM should be around 600 RPM at 66V and 525 RPM loaded, which is roughly 40 kph.

This is what your intending to power at 100+ volts too???

What controller will you use? What controller do you have now?

[cwah]

Sorry, didn't see your post.

Yes this is what I intend to boost at 100V+.. for now

I use Lyen racing controller for that

[zzoing]

i always pack my battery in a box made of polyethelene foam sheet i got for solar panel packaging, its kinda rigid and easy to work

[cwah]

Do you only use foam sheet to protect the battery?


I have a polycarbonate box with a layer of foam sheet to protect the pack. It already felt on the floor multiple times so better be sure