Hi Peri,
I've designed an open source BMS and cell packaging system, if you don't
want to design your own.
You need to source some pretty amazing lithium ion cells for that 53C
discharge rate! I think you might end up with a larger battery to get
that big C rate.
Anyway it's free to use if you want here is the website for all the
files. https://github.com/offgridsystems
There are some parts up on ebay if you don't want to make/order your
own.
https://www.ebay.com/sch/i.html?_from=R40&_trksid=m570.l1313&_nkw=dkblock&_sacat=0
Also a website if you want so build information.
https://dkblock922508958.wordpress.com
You may need to reprogram the Teensy (arduino like) controller (using my
code) for your application.
Cheers,
Tim Economu
Offgrid Systems LLC
Whidbey Island
On 4/14/2020 11:36 AM, [email protected] wrote:
Message: 1
Date: Tue, 14 Apr 2020 04:33:04 +0000
From: "Peri Hartman"<[email protected]>
To: "Electric Vehicle Discussion List"<[email protected]>
Subject: [EVDL] custom battery
Message-ID: <em575bcbf7-9fae-4c9f-894e-03ccf9dc8157@peri-laptop>
Content-Type: text/plain; charset="utf-8"; Format="flowed"
Hi,
I need a battery with about 150Wh and a discharge rate of 8kW for up to
a minute or so. I've spent a few hours searching and there doesn't seem
to be anything on the market that fits this. There are, of course,
higher capacity batteries that can deliver 8kW, but that's not what I'm
after.
This isn't for an EV, so I suppose this is somewhat off topic, although
BMSs are a relevant topic to EVs. It's for a home appliance that I'm
prototyping.
I'm pretty sure I can find affordable cells that I can put together to
do this, but then I'm stuck with a custom BMS. I suspect that's the
route I'm going to have to take. So, let's talk about that.
Each cell (or group of parallel cells) needs a monitoring circuit (is
there a name for this?). And theses monitors need to communicate with a
BMS. I'm less concerned about designing the BMS as I think I can use an
arduino and do it in software. The arduino can control the charger, too.
I can revisit this later. But for the monitors, I need to get it right.
Since the battery will be in the house, it cannot cause a fire. Ever. Of
course, I will have over temperature sensors which shut off the charger
and shut off the load.
Here's what I think each monitor's role is, based on what I've read on
EVDL over the years and some common sense:)
- cell over voltage
- cell under voltage
- cell over current
- cell temperature
In all of the above the circuit should shunt the cell.
In addition, the monitor should constantly report the cell voltage,
current, and temp to the BMS.
If there's something reliable I can buy, at a reasonable price, that's
my first choice. Otherwise, I guess it's getting someone to help design
and fabricate these.
I would be grateful for your suggestions.
_______________________________________________
UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
ARCHIVE: http://www.evdl.org/archive/index.html
INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org
Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)
