# BMS recommendations



## jbman (Oct 26, 2017)

Do we know for sure that the Model 3 pack is using a different messaging scheme?

Sent from my SM-N960U using Tapatalk


----------



## The_Sasquatch (Feb 11, 2018)

Based on what EVTV has published, it is a completely different system... It is possible the messages are the same, but the communication protocol is different... It's an obscure chip using an obscure protocol, I don't think anyone has even figured out how to record the message yet.


----------



## retrEVnoc (Mar 23, 2019)

I'll bump this thread as I'm in the same boat. Will begin attempts to integrate Model 3 battery modules to EV build later this year. Here's to hoping more progress is made on hacking these batteries soon!

Sasquatch what's your vehicle?


----------



## retrEVnoc (Mar 23, 2019)

The_Sasquatch said:


> My build is progressing quickly, I need some BMS advice. I am using a full 96s lithium ion Tesla model 3 pack. 355v nominal, 400v fully charged. Since the internal battery management boards haven't been cracked yet, I need to add an external BMS. It looks like wiring will be simplified by soldering or crimping to the battery management board terminals, so distributed BMS solutions won't work. Right now I'm leaning towards the thunderstruck dilithium BMS, but I'm open to other options... I am also looking at the Orion BMS.
> 
> The one thing neither of these offer is CCS DC fast charging support. Is there any BMS on the market that does? What is everyones opinion of the best BMS on the market right now?


Sasquatch check the latest video by Rich Rebuilds; it’s about EVWest shop and there is a quick thing in there showing an old truck waiting to have model 3 modules installed. So apparently someone who knows what they’re doing seems to think it’s possible. Great sign!


----------



## The_Sasquatch (Feb 11, 2018)

retrEVnoc said:


> Sasquatch what's your vehicle?


1985 Dodge ramcharger 4x4. I have a build log going here, just updated it. I have decided on using the Orion 2 BMS.


----------



## LukeJ (Oct 12, 2021)

The_Sasquatch said:


> My build is progressing quickly, I need some BMS advice. I am using a full 96s lithium ion Tesla model 3 pack. 355v nominal, 400v fully charged. Since the internal battery management boards haven't been cracked yet, I need to add an external BMS. It looks like wiring will be simplified by soldering or crimping to the battery management board terminals, so distributed BMS solutions won't work. Right now I'm leaning towards the thunderstruck dilithium BMS, but I'm open to other options... I am also looking at the Orion BMS.
> 
> The one thing neither of these offer is CCS DC fast charging support. Is there any BMS on the market that does? What is everyones opinion of the best BMS on the market right now?


 Were you able to get your model 3 battery pack to work? If so, I have lots of questions


----------



## Dillzilla (Aug 6, 2021)

For CCS look into the BMS LIM unit. With a openinverter VCU you can actually use the LIM to do CCS charging.


----------



## Dillzilla (Aug 6, 2021)

LukeJ said:


> Were you able to get your model 3 battery pack to work? If so, I have lots of questions


Same here. I was thinking of trying to make a connector.


----------



## remy_martian (Feb 4, 2019)

Dillzilla said:


> For CCS look into the BMS LIM unit. With a openinverter VCU you can actually use the LIM to do CCS charging.


LIM is nothing close to being a BMS, nor is the VCU.

EVTV had a BMS for the Model 3 modules that it was using in its Powerwalls.


----------



## Dillzilla (Aug 6, 2021)

remy_martian said:


> LIM is nothing close to being a BMS, nor is the VCU.
> 
> EVTV had a BMS for the Model 3 modules that it was using in its Powerwalls.


I understand that. The openinverter VCU supports it though. If you have a Orion BMS and a openinverter VCU you can use the LIM to get CCS charging.


----------



## remy_martian (Feb 4, 2019)

Now you've added the Orion BMS after calling the LIM a BMS...do you see the trail of confusion you'd sown?

Most DIY conversions are fine with AC charging, Level 1 or Level 2.

K.I.S.S.

There's a lot of engineering involved in DC charging as far as pack conditioning goes. I see very few people here adding the thermal support needed in their builds beyond "hey you can use a LIM". What you see actively posting on OpenInverter are hardcore engineers and even some of them appear to be going cowboy on charge rates vs pack cooling.

An off the shelf BMS backing off charge rates to 3kW because of a homebrew pack build's inability to dump heat at a public station will piss a lot of EV owners off and get complaints registered. Charger OEM's will threshold those vehicles out and refuse to charge them for revenue reasons.

A few homebrew fires due to hot charging, ignoring battery monitoring and conditioning at public stations and we are all banned.

AC charging is good for 95% of the builds here, there's zero shame in it, and having CCS is a crappy brag when your car makes the evening news or you wasted a lot of time and money only to have the CCS stations refuse to charge your car because it's not drinking fast enough from their firehose.


----------



## Dillzilla (Aug 6, 2021)

remy_martian said:


> Now you've added the Orion BMS after calling the LIM a BMS...do you see the trail of confusion you'd sown?
> 
> Most DIY conversions are fine with AC charging, Level 1 or Level 2.
> 
> ...


The post saying "BMS LIM" was a typo. It was supposed to say BMW. Nowhere was I trying to imply that the LIM is a BMS. I was saying to look into it for DC fast charging because currently that is the cheapest and most reliable way of getting fast charging at this point in time.


----------



## remy_martian (Feb 4, 2019)

It's not the cheapest way of charging if you cannot keep up with a 50kW charge rate minimum. That means installing a chiller (air conditioning compressor, HEX and condenser) on your battery pack cooling loop. Which is not cheap and requires sophisticated management software few here can write.

What gave you the idea CCS was the cheapest? I charge at $0.12/kWh on AC and it's $0.30/kWh on DC fast charge with the Bolt EV. 

Unlike apartment dwellers who need CCS because they have nowhere to plug in for AC, if you build a car, you have an AC outlet for charging. 

Anyone who's built a car knows about the 500 mile towing charges if they dared to take it on a trip (no shop will try to fix a homebuild).

Half the EA CCS chargers seem to be down at any site I've used (it's a running joke you share with others while charging), so no idea where you got reliable from either. In USA, anyway.

Then there's home charging. A CCS charger for your garage/driveway is at least $4 grand...which means you have AC charging already in your build.


----------



## Dillzilla (Aug 6, 2021)

remy_martian said:


> It's not the cheapest way of charging if you cannot keep up with a 50kW charge rate minimum. That means installing a chiller (air conditioning compressor, HEX and condenser) on your battery pack cooling loop. Which is not cheap and requires sophisticated management software few here can write.
> 
> What gave you the idea CCS was the cheapest? I charge at $0.12/kWh on AC and it's $0.30/kWh on DC fast charge with the Bolt EV.
> 
> ...


My comment was specifically referring referring to fast charging. If you had actually read what I said you would know that.


----------



## remy_martian (Feb 4, 2019)

You are talking everybody you can find into fast charging, whether you realize it or not. One of the fundamental things in market surveys is not to ask if someone wants a feature that's perceived as "better", "best", or "lower cost", because the answer is always a resounding yes.

Trolling fast charging not appropriate given 90% of the skill level and breadth of knowledge on this forum and is inviting Biblical proportion disaster at public CCS stations because everybody wants CCS but almost everybody in DIY doesn't need it, nor do they know how to engineer a system to accommodate it. The five or six boffins on OpenInverter absolutely do...but they're too busy nerding out to realize what they are unleashing.

You're basically in violation of the Prime Directive and they inadvertently are, though there is a disclaimer that it's not ready yet that everybody ignores.

Those that absolutely need CCS will find out what's out there and use it. The reckless will also find it and use it. Inviting those that don't know better through "it's cheapest" or "better" or "faster" vs pointing out the other needs besides a couple of boxes engineers have unleashed is irresponsible.


Saying it's the cheapest, while requiring $2000 in boxes to support it is also not true.

All those months of work destroyed by people camping out on CCS stations with air cooled batteries, trickle charging while a Mach-E jockey is waiting his/her turn, or having one not manage thermals is begging for an outright ban on charging nonfactory vehicles of any kind built by anyone.

If someone has the abilities, they'll seek out what they need. You don't need to promote it or publicize it because the answer is always yes if people become aware of "all ya gotta do it buy three boxes and a plug", if someone tells them it's the cheapest, and even the guy who doesn't know oil from antifreeze appears to be planning to use it 😬 because CCS is a "cool" checklist item, probably, and you "only need three boxes and a plug and it's the cheapest out there"


----------



## Dillzilla (Aug 6, 2021)

remy_martian said:


> You are talking everybody you can find into fast charging, whether you realize it or not. One of the fundamental things in market surveys is not to ask if someone wants a feature that's perceived as "better", "best", or "lower cost", because the answer is always a resounding yes.
> 
> Trolling fast charging not appropriate given 90% of the skill level and breadth of knowledge on this forum and is inviting Biblical proportion disaster at public CCS stations because everybody wants CCS but almost everybody in DIY doesn't need it, nor do they know how to engineer a system to accommodate it. The five or six boffins on OpenInverter absolutely do...but they're too busy nerding out to realize what they are unleashing.
> 
> ...


Calm the fuck down. He specifically asked about a BMS with CCS charging so I gave an answer. Yes I am aware that you have to cool the batteries. I'm assuming someone who is specifically asking about CCS charging is aware of this. Now get off that high horse of yours and shut the fuck up if you have nothing useful to say.


----------



## remy_martian (Feb 4, 2019)

Sorry. You're not my mother to tell me to STFU and I won't, in any case, while you continue to be a thick skulled zealot who doesn't get it.

You CANNOT *assume* someone who sees or knows about a CCS charger knows what it takes to implement it - it is not "all you need is three boxes and you're good for 200amps" (they can command that from a laptop like Damien did and nothing stops them). That's where you FAIL, buddy.

All it takes is a couple of people taking out a CCS charging station or two and the station access gets shut down for everybody DIY worldwide...MIT PhD in EE won't get you into the OEM club of approved to charge after that.

A charger capable of delivering a third of a megawatt of energy can be forced to butt heads with an instantaneous circuit fault of a thousand or more amps at 400V if a cell shorts out in the car from overstress. There are currently NO recommended fuses in the reference block diagram between the charging cable and the battery stack in the car.

Stop pushing everyone's luck...it's not your creation so I don't get being a reckless ("I assume...") zealot about it. It's there, it's not ready, so it should be obvious who should STFU about it.


----------



## Dillzilla (Aug 6, 2021)

remy_martian said:


> Sorry. You're not my mother to tell me to STFU and I won't, in any case, while you continue to be a thick skulled zealot who doesn't get it.
> 
> You CANNOT *assume* someone who sees or knows about a CCS charger knows what it takes to implement it - it is not "all you need is three boxes and you're good for 200amps" (they can command that from a laptop like Damien did and nothing stops them). That's where you FAIL, buddy.
> 
> ...


You aren't anyone's parent either. If you have a problem with information being shared when people ask for it then you are in the wrong place. That is the whole point of this forum. As for safety there is inherent risk with everything on this forum. Doing DIY EVs is going to be inherently risky. CCS charging doesn't change that. So again, get off your high horse for a second and stop acting as if sharing information on a forum meant for sharing information is bad.


----------

