Hello from Montréal - Canada


New member
Dec 30, 2020
Hello Second Life Storage's community !

Who am I ?
I'm Ben (35), from Montréal - Canada . Right now under a little snow storm ^^
I speak French (originally from France) and English since living in Montréal (sorry about the mistakes... might not be perfect).
I guess this forum is more dedicated to English written but feel free to message me in both.

I have been reading quite a lot about different projects and storage of energy. After a while, I decided to start my own little project.
This project is more a way for me to learn, play, discover and mostly have a lot of fun. I will be trying to build a small storage of energy kind of a power wall.

My background in electronic/electricity is close to 0 (forgot everything I learned at school...), so i guess it is a really good challenge ! I hope you'll be remembering the days you started your own journey ;)
I'm a computer science guy (SysAdmin/Cloud/Security) and I usually work on software rather than hardware... but I hope to change this aspect as of today!

What am I looking for ?
I'm really looking to understand the safety rules (first) and to build system's that respect the standard of safety.
To fully understand what I'm doing (it's best ^^)
To share and document as much as possible for the community
To get different point of view on projects and builds

What is my project ?
I will open a specific thread for that maybe ? So I can expose more about it. I will provide.

But In short:
I bought 15x BAE A123 Systems Battery from Transit Buses (used). They are 40V and 2250A each modules (12S8P) .
I would like to use them as is, to build a storage bank of energy that I can use when there is a power outage. Just to run basic appliance like lights, phone/computer chargers, if possible microwave or kettle. I know the last two require more than 1500W so maybe not necessarily.
And I would like to use my house power (the grid) to charge it and keep it ready to use. I don't know if is best to keep the pack charged all the time , or to cycle it a little bit.
Ideally I would like it to have it connected (somehow) on my in-house circuit breaker so I can use the existing outlets and stuff without trouble. But I live in an appartement and I don't see how I would be able to do so. And of course I don't want it to back feed the building or the grid.
So I would maybe just start is an inverter that already has outlets. And upgrade later.

Most of system seems to work in 24v or 48v but I the modules I got are 40V , I don't really see if it's a big deal or not. Most inverter are 24v, 48v or 72v , but there is also a bunch of them that take any range from 12v to 72v so i'm a bit lost.

So far, I don't understand much the BMS possibility on parallels packs. Like if I have 15 modules in parallel. can I have just one BMS that will connect all the first series to the first entry of the BMS , etc.. for the 12S . Meaning I have 12 Rows where I can connect the 12S of each pack to each Row that finally connect to the BMS Or if I have to get one BMS for each modules . But I want to charge the full pack, not each module a one time.

I did not understand yet how I will be able to charge the full pack :) Have to read about the options.

Anyways , I am in the very early stage and will be happy to explain more and chose as I learn what can be best into this kind of setup.
Anyone that will be interested in doing some "helping/coaching" is welcome we can save some hours of writing with a quick call.

What else ?

2021 is almost here. So I wish you all a very nice end of the very unique 2020.
All the best for you projects and most of all, lot of fun, laugh, joy and compassion for next year.



Well-known member
Dec 15, 2018
Welcome to the forum!

>... in an appartement and I don't see how I would be able to do so. And of course I don't want it to back feed the building or the grid.
This would be an offgrid system. Solar panels? or is the more of a battery+inverter that you want to charge from the grid?

An example of a 24v/48v all-in-one offgrid unit is a PIP (Mpp Solar) I just bought a 48v / 3000w unit and it charges your battery from the grid (no solar panels required) but also accepts solar panels if you wish. Here's an example of a straight-forward battery+PIP setup -

>seems to work in 24v or 48v but I the modules I got are 40V , I don't really see if it's a big deal or not.
The reason for 24v or 48v is because it leads to a good choice of products / price. I would start a search for a 40v inverter and this will yield a key piece of info for you to plan around. If you find one - great. If you don't, then maybe reconsider re-wiring the cells to 16s.

In any case - look forward to hearing what you decide and progress on your efforts!


Active member
Aug 23, 2017