[PStechPaul]

What are you using for a balance monitor, and how is it connected? The self-powered meters may be rated for 48V, but the internal regulator might not handle the maximum 56 volts of a fully charged 4x12V lead-acid pack.

 

[Functional Artist]

What are you using for a balance monitor, and how is it connected? The self-powered meters may be rated for 48V, but the internal regulator might not handle the maximum 56 volts of a fully charged 4x12V lead-acid pack.

Hey Paul,
I use my DBBM (Digital Battery Balance Monitor) to monitor the balance of the battery pack.
https://www.youtube.com/watch?v=uzwUiSl0Azg

Its directly wired to & plugged into the (stock) Chevy Volt BMS plug.

It's switched so, it does not draw any power except when switched on (& so far) I only use it momentarily to check the balance before & after a ride & also before & after charging.
(it doesn't need to be on & displaying a reading constantly)

If you remember, I killed the (4) SLA's last winter, I now have a (45V nominal) 2kWh section of a Chevy Volt battery pack on it & I only charge it to 49.8V.

 

[PStechPaul]

My question was for the previous poster: Miaplacidus82

 

[Functional Artist]

My question was for the previous poster: Miaplacidus82

Oops
IDK what that post was about, definitely need more info

 

[dain254]

I'm curious why go through all the hassle to monitor balance? Unless you are drawing over 500A all the time the pack will tend to remain in balance for several cycles. The electric motorcycle I recently build using an old dirt bike also utilizes the 2kwh Volt module. So long as you are monitoring full pack voltage - a 12S BMS has gotten so cheap these days that it seems silly to me to not use one - and the only time it needs to be used is during charging (which is how I charge my modules). My top speed is only 40mph or so, but with an 800A controller it will flip over backwards - attached a pic of the bike for fun. I'm curious also what range you are seeing with the 2kwh pack, I was thinking of getting mine registered for street use and changing sprockets to get 60mph.

 

[Functional Artist]

I'm curious why go through all the hassle to monitor balance? Unless you are drawing over 500A all the time the pack will tend to remain in balance for several cycles. The electric motorcycle I recently build using an old dirt bike also utilizes the 2kwh Volt module. So long as you are monitoring full pack voltage - a 12S BMS has gotten so cheap these days that it seems silly to me to not use one - and the only time it needs to be used is during charging (which is how I charge my modules). My top speed is only 40mph or so, but with an 800A controller it will flip over backwards - attached a pic of the bike for fun. I'm curious also what range you are seeing with the 2kwh pack, I was thinking of getting mine registered for street use and changing sprockets to get 60mph.

Howdy,

Being extra, super careful.

Have you ever seen a lithium battery "gas out"? It's "wicked".

I definitely don't ever want that happening between my legs or in my garage.

These Lithium batteries are totally new technology to me, that's why I did all of that research on BMS's, charging & monitoring.

I'm just tryin' "to do it right" or at least safely.

The meters let me know what's goin' on inside of the battery pack.

As far as I know the "jury is still out" on those cheap BMS's because there are so many variables like quality, compatibility (to specific situations) & then the proper installation & use.

I've also heard of many folks who got over-confident because "I have a BMS", didn't keep a proper eye on things & bad things happened.


* BTW Nice bike. What motor/controller are you using?

 

[dain254]

I can certainly understand the desire to be extra super careful! I personally haven't had any lithium batteries go up and I don't plan to! One thing I would like to suggest to you that I did before using legit BMS' is taking the standard BMS harness from the volt, and adapting a plug to it use with a hobbyking battery medic. I have one of these made for the 6S 1kw modules I use frequently, I can post a pic later. Link to a battery medic is here:

https://hobbyking.com/en_us/hobbykingtm-battery-medic-system-2s-6s.html

They are typically only used for RC vehicle sized batteries, but will also work with the Chevy Volt modules (balancing takes a lot longer). for the 12S module you simply need 2 of them, and you have a super super cheap way to monitor AND balance the pack all the time at an individual cell level! When I built my first electric vehicle with a 20S lithium pack I had an array of 4 of these (5S in each) mounted in front of me so I could see each cell all the time. It actually worked great!

Thanks for the compliments on the bike - I'm using a Motenergy ME1003 and Kelly KDZ72801E (regen version). Motor gets hot if you are riding through sand or mud but works great otherwise!

 

[Functional Artist]

I can certainly understand the desire to be extra super careful! I personally haven't had any lithium batteries go up and I don't plan to! One thing I would like to suggest to you that I did before using legit BMS' is taking the standard BMS harness from the volt, and adapting a plug to it use with a hobbyking battery medic. I have one of these made for the 6S 1kw modules I use frequently, I can post a pic later. Link to a battery medic is here:

https://hobbyking.com/en_us/hobbykingtm-battery-medic-system-2s-6s.html

They are typically only used for RC vehicle sized batteries, but will also work with the Chevy Volt modules (balancing takes a lot longer). for the 12S module you simply need 2 of them, and you have a super super cheap way to monitor AND balance the pack all the time at an individual cell level! When I built my first electric vehicle with a 20S lithium pack I had an array of 4 of these (5S in each) mounted in front of me so I could see each cell all the time. It actually worked great!

Thanks for the compliments on the bike - I'm using a Motenergy ME1003 and Kelly KDZ72801E (regen version). Motor gets hot if you are riding through sand or mud but works great otherwise!

Everything I have heard is that these Volt packs are extremely well matched (on many parameters) & very stable (as a whole).

How often have your Volt packs been "out of balance"?
...or do you just balance while charging "to be sure"?

The theory I'm working under is:
Start with a professionally engineered & manufactured battery pack (not DIY)
...monitor the balance (just to be sure)
...& use a charger specifically set to only charge the battery to ~49V. (98 or 99% capacity, for a small "safety margin").


* The motor looks dinky in the pic.
…& an 800A controller, Wow!

 

[dain254]

I would say they are very well matched as well. All of your information is correct. I only balance charge them just to be sure - a person could certainly not balance for a few cycles and likely be fine. I also have been charging mine all the way up to 50.4 - yes ideally you would stop somewhere at 48 or 49 to be gentle on the pack. I don't do that because I'm lazy and want my extra couple volts for maximum power!

It's a little hard to see the motor as it is behind the mounting plate - it's 35lbs or so. As far as the controller putting out 800A - I think on the taddle tale the highest I"ve seen is 470A, the chinese controllers are always quite a bit weaker than they are rated for some reason.

 

[Functional Artist]

Volt Battery Pack update

The bike has been put away since mid October.

I have checked the battery pack every couple of weeks, just to be sure
...& the balance monitors have shown 24.3V in each half of the battery pack consistently.

A few weeks ago a Polar Vortex came thru the area (actually 1/2 of the frickin' country)
...& we saw a few days of -15 temps, with -30's wind chills.

I'm happy to report that the balance monitors are both still showing 24.3V

 

[Functional Artist]

100 electrical miles

Since I converted this motorcycle to electric back in August of 2017, I had only put ~34 (electrical) miles on it.

I think I put ~ 27 miles on 'er, test riding around a Wal-Mart parking lot @ 36V.
...& then it looks like I only put ~ 7 miles testing 'er riding around my neighborhood @ 48V SLA
...& also @ 45V Lithium.

Mainly, because I was NOT "legal". I didn't have a motorcycle license or the proper insurance coverage.
…so, I just let 'er sit. (worked on other stuff)

Well, this year I didn't wanna "just let 'er sit"

So, now I have a motorcycle license, plates & insurance
…& just passed the 100 (electrical) mile mark

I got ~27 miles on 'er during this last ride before the low voltage "shut off" kicked in

So, in this (45V 47AH) configuration, I seem to have a ~25 range

I'll probably stick to ~20 miles (~10 miles each way) just to be safe.

Is that good?
...or considered average?



* A while back, (before I got banned) some of the guys on ElMoto (the electric motorcycle forum) were concerned about my chain routing/set up.

1.) They told me that my 10 tooth drive sprocket was too small
…& will wear prematurely
(~15 tooth drive sprocket is usually the minimum size sprocket that they recommend)

2.) They also didn't like where I mounted my "idler" sprocket
...to help route the chain around the swing arm
(they said, my chain did not "wrap" around the drive sprocket enough)

** For the record, @ the 100 (electrical) miles mark, (I'm happy to report) that there does NOT seem to be ANY wear on the drive sprocket
...the idler sprocket
...or on the driven sprocket either.

Didn't even hardly seem to wear any of the paint off (see pics)
...but, I'll keep an eye on 'er.

 

[jonescg]

That's a rather ...unique setup

I think there's enough chain wrap on the drive sprocket, so don't worry about that. The chain pull on the rear sprocket is not ideal, as it will cause the swingarm to squat under hard acceleration. This doesn't look like a performance machine though, so it won't be a deal breaker, but it will make the bike run wide as you power out of a corner.

 

[Functional Artist]

I've been doin' some riding & testing

I went & found a big bridge to see how well the bike would "take it"

I also did some recording of the meter, to see what kinda amps she would draw while "doin it".

Here is a video of the ride


https://www.youtube.com/watch?v=3cBgnbR_mPc


…this is the bridge.

 

[Functional Artist]

Well, I've got over 250 miles on 'er now & I'm happy to report that (knock on wood) everything seems to be goin' good.

The bike runs great, is very nimble & has great acceleration
...like 0 to top speed (35MPH) in ~4 seconds

So, I gave everything a good "lookin' over"
...went around double checkin' the bolts
...& the inspected the sprockets again (& they still aren't showing any wear)

I also installed an analog amp meter, to get some data that we can compare with the data that we got from the digital amp meter.

Then, I took 'er for a ride to get some data with the analog amp meter.
(went to go visit the big bridge again)


https://www.youtube.com/watch?v=5CpeS5ENA18

 

[Functional Artist]

With all of the sh*t that was going on last year (2020), I forgot about doing a 500 mile update.

To catch ya all up, the bike still rolls out great, no noticeable wear on any of the sprockets & the battery pack is doing good too.

The pack seems to still have the same capacity as @ 250 miles & the balance monitors have always been "in sync".

I also, got a new cover & re-did the seat. It really makes a difference in the looks & feel.

I did a video on re-covering the seat, if anyone is interested.

 

[Functional Artist]

Next. I figured I'd try a PZEM-051 meter (seemed to work pretty good on my Excalibur kart)
I was interested to see/test the capacity of the battery pack (not just amp draw)

My only concern is that this meter is labeled/rated @ 100V/100A

The batt pack is ~48V so, were good there
...but, this motor can pull well over 200A so,..

* I didn't think it will "fry" the meter, as no current actually flows thru it (it's just reads a signal)
...but, maybe it would just "blank out" or show an 0

The meter actually did really good

It showed me starting off @ 49.15V & recorded 1,600Wh used running the pack down to 34.5V (~2.8V per cell)
* yes, I know it's not good to discharge these packs below ~3V per cell
...it was only a test & never happened again

Here is the video of my ride, it's not super exciting just mostly to gather data