Tesla module charge profile for EPEver Tracer series.

[shizenyasuya]

I've been following Will's youtube channel for a long time, and I finally got around to buying a Tesla battery module for my off-grid project. The DIY tesla video has a segment on the charge profile for that charger, and there's a spot he glossed over, saying it didn't matter too much, but with an image over the bottom of the screen stating to check the website because he's fine tuned the profile. I checked the website, but I can't seem to find the fine-tuned profile. Is anybody else using this setup or have suggestions for keeping a Tesla battery module happy with the charge profile? I've got the maximum charge voltage set to 24.8, overcharge disconnect set to 25.0, and the low voltage disconnect is set to 19.8, with a low voltage warning at 22 volts, but there were so many other parameters to set, that I would like to fine tune as well. If anybody has a recommended setup, I'd love to hear it.

 

[tictag]

I think you might be over-complicating this. The charge profile is determined by the cell chemistry and layout, which for Tesla batteries has changed model-to-model, year-to-year (according to https://en.wikipedia.org/wiki/Tesla_Model_S). Once you know the chemistry and layout, you can determine the charge profile using sites like https://batteryuniversity.com/learn/article/types_of_lithium_ion.

For example, for a 6S74P NCA module pack (from the 85kWh battery pack) you're looking at a CC/CV charge profile at 25.2V (6 x 4.2V = 25.2V) current limited to 0.7C, according to the sources provided above.

 

[shizenyasuya]

Thank you

 

[PfloydBham]

Thank you

I have a Tesla "S" module, 5.2 Kw with an Epever 4210 BN which has a "user defined" setting. I used a MT50 to set the charge parameters and just followed the guide that Will suggested which is about 24.4v overcharge cut off. I use a victron BP220 at 19v overdischarge cut off. Hope this helps.
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[PfloydBham]

Thank you

Sorry, I did not read the entire post. I think those parameters are about all that you need to get the most out of the unit without a chance of damage. If you reduce the limits a little, the batt will get more charge cycles. I have heard they may go as many as 20,000 cycles in a low demand set up.
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[dossamosas]

Was Will's fine-tuned profile published and then taken down?

 

[Geriakt]

I limit my charge from 19 volts to 24.4 volts on my two Tesla 5.3KWhr 444 cell 233 AH modules. As you get closer to the max charge of 25.2 volts you better have a good BMS system to make sure you do not over charge on an individual cell value of 4.2 volts or bring out the good for the wennie roast.

 

[PfloydBham]

This link should take you to all Will put out on the Tesla set up he did.

DIY Tesla Solar Battery

How to use a Tesla Model S for a DIY powerwall solar battery

www.mobile-solarpower.com

Does anybody have a BMS they would recommend for Tesla.
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[Geriakt]

This link should take you to all Will put out on the Tesla set up he did.

DIY Tesla Solar Battery

How to use a Tesla Model S for a DIY powerwall solar battery

www.mobile-solarpower.com

Does anybody have a BMS they would recommend for Tesla.
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i am using the Electrodacus SBMS0 for each of my Tesla Modules.

 

[Sabotcat]

Hey! Not to hijack, but two quick questions along the same lines. Has anyone used a tesla battery with an MPP all-in-one? Are they sufficiently programmable that you can pull it off? I have two tesla S batteries in series on a system with a Midnite Solar Classic 150 and it runs like a top. No BMS, nothing ever gets warm. But I'm putting in a second, smaller system and want to use one Tesla battery and try to simplify things. Would love to try an All-in-one, but I want the same performance I'm getting from my two batteries connected to my Classic 150 and my Schneider 4048.

Does anyone have any thoughts?

 

[PfloydBham]

i am using the Electrodacus SBMS0 for each of my Tesla Modules.

Do you have a diagram of how you set your system up you can share? I built mine about 9 months ago and had to put it on hold at about 95% complete due to a terminally ill family member. I am about to rethink it and I want to use a BMS rather than simply relying on the charge settings and the BP220 for under voltage. Unfortunately, I am both ignorant and senile so it is easier for me to just steal somebody else's intellect.
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[Sabotcat]

Pfloyd!

I'm in the process of doing the same thing...and unfortunately, the Tesla Module I just picked up is an older one...and the Green BMS board was soldered on...so I'm going to have to cut the wires to take it off. But if you look behind the green Tesla BMS and you see Molex style wire attachments you can remove the proprietary Tesla BMS board...then the easiest thing to do is probably go to somewhere like Stealth EV in California and get a board to replace it (https://stealthev.com/product/tesla-model-s-x-battery-module-bms-cell-tap-board/) This has none of the circuitry but gives you a solid port into which you can connect a BMS.

On my existing system (Midnite Solar Classic 150 and Schneider 4048 inverter, I am running two tesla modules in series for 48 volts. On my small cabin I haven't had any issues whatsoever without a BMS, but my system is small.

For my new system I am going to plug a cell balancer (ISDT Battgo) into the old Tesla BMS wires and then connect a Victron "Smart Sense" temperature and voltage monitor separately that will communicate with my Victron Charge Controller. Its a bit of a cobbled together solution, but all I really want is a high voltage cut-off to prevent overcharging...a low voltage cutoff to prevent over discharging and a temp gauge that can make sure I never deliver a charge the batteries when the temperature dips below freezing.

But again, if your system is oversized, your wires are thicker than they need to be, and you don't pull a lot of AMPS...which is my current situation...you should be fine. But the simple "Battery Balancer/Temperature Sensor) combo plugged into the wires that are connected to the Batteries within the module should give you some piece of mind.

 

[Geriakt]

Do you have a diagram of how you set your system up you can share? I built mine about 9 months ago and had to put it on hold at about 95% complete due to a terminally ill family member. I am about to rethink it and I want to use a BMS rather than simply relying on the charge settings and the BP220 for under voltage. Unfortunately, I am both ignorant and senile so it is easier for me to just steal somebody else's intellect.
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You can send me a PM and provide an email. I do not have CAD schematic, but i have some hand drawn diagrams. I can provide some advice. I dont recommend not using a bms with the Tesla Module. Others are willing to take the risk and that is fine.

 

[PfloydBham]

somewhere like Stealth EV in California and get a board to replace it (https://stealthev.com/product/tesla-model-s-x-battery-module-bms-cell-tap-board/) This has none of the circuitry but gives you a solid port into which you can connect a BMS.

Thanks, this is gigantic for me. I took on this project knowing little more than how to change the D cells in a flashlight.

all I really want is a high voltage cut-off to prevent overcharging...a low voltage cutoff to prevent over discharging and a temp gauge that can make sure I never deliver a charge the batteries when the temperature dips below freezing.

That's pretty well where I am except I am pretty sure I should tighten it up a little since I am going back through from stem to stern (loosely

But again, if your system is oversized

It sort of is ... oversized. I intend to run a fan, a tv, laptops, lights and so forth for the most part. briefly -- microwave, hair drier, coffee, etc. Hopefully as I realize what a big ocean I am now swimming in, I will get a little more sophisticated.
This reminds me of going to a U2 concert (Achtung Baby!). Information overload.
Can't thank you enough.
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