DIY Electric Car Forums banner

1 - 8 of 8 Posts

·
Registered
Joined
·
152 Posts
Discussion Starter #1
Yes I see I can make them pretty easily. BUT if anyone has some laying around - or is already setup to make them easily - I'm interested.

Thanks!
-Ocean
 

·
Registered
Joined
·
396 Posts
I have been making & experimenting with Batt-Bridges recently.

As you probably, already know Batt-Bridges are voltage specific.

What is the voltage of the battery packs that you need the (6) Batt-Bridges for?

I may be able to make a few for you. :D
 

·
Registered
Joined
·
152 Posts
Discussion Starter #3
I have been making & experimenting with Batt-Bridges recently.

As you probably, already know Batt-Bridges are voltage specific.

What is the voltage of the battery packs that you need the (6) Batt-Bridges for?

I may be able to make a few for you. :D
Hey Thank You! That would be amazing!...

So my setup looks like this: I have my Bradley EV loaded with Chevy Volt Lithium batteries. Each Volt module is 12s. I have sets of two modules in series, for 24s, which yields a max voltage of 100v (24 x 4.1xx) - and a min voltage of 72v @ 3v/cell.

I have 6 of these (24s, 100v) strings running in parallel.

Since each string has two modules in series, it would be easy to connect one bridge to the center of each string.

And this is why I'm wanting 6 Bridges.

Not sure what color LED's you have, but I was looking at bright RED / BLUE (Blue in Center, Red indicating imbalance)

This because I am Red / Green colorblind... and also I like blue.

Well if you are into it I would be very grateful... anything I could do for you in exchange? I make some nice cabinet / door handles in my woodshop (crafted from Manzanita, our local, beautiful, curvaceous tree)... or??$?

thanks again for this possibility!
 

·
Registered
Joined
·
396 Posts
Hey Thank You! That would be amazing!...

So my setup looks like this: I have my Bradley EV loaded with Chevy Volt Lithium batteries. Each Volt module is 12s. I have sets of two modules in series, for 24s, which yields a max voltage of 100v (24 x 4.1xx) - and a min voltage of 72v @ 3v/cell.

I have 6 of these (24s, 100v) strings running in parallel.

Since each string has two modules in series, it would be easy to connect one bridge to the center of each string.

And this is why I'm wanting 6 Bridges.

Not sure what color LED's you have, but I was looking at bright RED / BLUE (Blue in Center, Red indicating imbalance)

This because I am Red / Green colorblind... and also I like blue.

Well if you are into it I would be very grateful... anything I could do for you in exchange? I make some nice cabinet / door handles in my woodshop (crafted from Manzanita, our local, beautiful, curvaceous tree)... or??$?

thanks again for this possibility!

A Bradley loaded with 2kWh Chevy Volt battery packs, that's great!

...those are the ones, I have been making Batt-Bridges (BPBM) Battery Pack Balance Monitors for.


Those 2 kWh Volt packs are ~44.4V -45V nominal

...so, you need BPBM's to monitor ~90V battery packs?


I have been color coding my BPBM's

...yellow LED's for 24V

...red LED's for 48V

...so, ya, blue LED's for 90V works for me :D


What are your installation & use plans?

1.do you want to hard wire the (6) BPBM's right on to the battery packs?
(like for, quick checks before trips, before charging & periodic monitoring)

2.do you want the (6) BPBM's mounted to the dash & hard wired to the battery packs for constant monitoring?

3...or (as an option) could you possibly use just (1) mobile unit, a "Spot Checker" I call it?

like this: https://www.youtube.com/watch?v=I8TX8guUsM4

...to manually check your battery packs individually?
(to know your packs are in balance before driving)
(&/or to check for cell imbalances before charging)


* From my research, these Chevy Volt packs are of good quality & well engineered/built.

...from reports from users, they seem to stay pretty well balanced

...so, periodic checking, especially before charging (may) be OK in this situation
 

·
Registered
Joined
·
152 Posts
Discussion Starter #5
A Bradley loaded with 2kWh Chevy Volt battery packs, that's great!

...those are the ones, I have been making Batt-Bridges (BPBM) Battery Pack Balance Monitors for.


Those 2 kWh Volt packs are ~44.4V -45V nominal

...so, you need BPBM's to monitor ~90V battery packs?


I have been color coding my BPBM's

...yellow LED's for 24V

...red LED's for 48V

...so, ya, blue LED's for 90V works for me :D


What are your installation & use plans?

1.do you want to hard wire the (6) BPBM's right on to the battery packs?
(like for, quick checks before trips, before charging & periodic monitoring)

2.do you want the (6) BPBM's mounted to the dash & hard wired to the battery packs for constant monitoring?

3...or (as an option) could you possibly use just (1) mobile unit, a "Spot Checker" I call it?

like this: https://www.youtube.com/watch?v=I8TX8guUsM4

...to manually check your battery packs individually?
(to know your packs are in balance before driving)
(&/or to check for cell imbalances before charging)


* From my research, these Chevy Volt packs are of good quality & well engineered/built.

...from reports from users, they seem to stay pretty well balanced

...so, periodic checking, especially before charging (may) be OK in this situation
That's awesome you are familiar and working with Volt Packs too. Yes as you say, I suppose they are about 90v nominal in my setup (running two modules in series for 24s). I just think of them in terms of the max charge voltage (about 100v).

My ideal scenario would be to hardwire the Bridges onto each individual pack. Some of them are hard to reach - the terminals being way back in the motor compartment. This way I could just have a quick look before I head out or when I return.

If the PCB were to have three 1/4" spade connectors - or even just short wires like 16guage, that would be ideal. This way I could run wires to the Pos, Center and Neg positions... then mount the circuit in a good location - probably on top of the Battery <black plastic terminal covers> themselves. At first I thought of perhaps mounting the pcb to the center post of the battery, but that could be problematic because of the orientation of some of the batts, and plus I like to keep the covers on them.

***
The Bradley is operational. I'm just now getting into using it.... currently working on a 2.4kW Solar Array to charge it up. One nice thing about this setup - with, essentially, 6 x 4kWh packs in parallel (24kWh total) - my mileage numbers are looking really good. So far I've gone 70 miles (30 trip plus 40 trip with minimal charging in between) - on each trip I calculate a "miles / volt" and I'm getting about 5.5 miles/volt. Not sure if the voltage curve will stay linear all the way down to 72v... but so far, with a voltage range of 28volts, i'm projecting a range upwards of 150 miles... at about 55mph pulling average 150amps from the whole pack - only about 25 amps per individual string!
***

Here's some pics so you can see what I'm working with... plus, I think the car would look really cool with little blue lights in the center of each battery pack ;)...

... and if one goes red, I'd be like "hey, what's going on!??" then I would investigate and hopefully just plug in a 24s balance charger on that one pack (don't have that yet... but it's the goal!)

thanks Mr. Functional Artist! ;)
-Ocean
 

Attachments

·
Registered
Joined
·
396 Posts
Sounds like a good plan :D

I have been gathering more/specific details on these Batt-Bridges (to build them properly)

Mr. Lee Hart even messaged me with some info.

When I went to his website, I noticed that he sells DIY Batt-Bridge kits as well as assembled units.

http://www.sunrise-ev.com/LeesEVs.htm

Batt-Bridge parts kit -- $10. Includes LEDs, resistors, lamp holder, and detailed instructions. Specify pack voltage. $5 for US shipping and handling.

Batt-Bridge, Assembled -- $20. Assembled Batt-Bridge in panel mounted lampholder, with resistors and detailed instructions. Specify pack voltage. $5 for US shipping and handling.

So, you may want to check it out

I am NOT looking to "step on any ones toes" here :cool:


He may be OK with using his technology in my artwork

...but, need to check FIRST
 

·
Administrator
Joined
·
6,115 Posts
Hi Guys
When I had four parallel strings I plugged them together using Alderson connectors - so when I got a fault in one string I could just disconnect that strine and keep on trucking
 

·
Registered
Joined
·
152 Posts
Discussion Starter #8
Thanks Art! I didn't even know Lee's website existed! So now I know it seems right for me to check it out. Seems very reasonable. Thanks again for your consideration, and pointing me in the right direction.

Duncan - yes, I will keep that in mind. In fact I would like ideally to find some 100 amp breakers so I can protect from a bad cell and disconnect individual strings when needed.

Cheers!
-Ocean
 
1 - 8 of 8 Posts
Top