BYD 24 volt 5k used liFePO4 order

[michael d]

Today, I just ordered these batteries with bms from techdirect.
hope all goes well. new to this.
I have 327 watt 64 volt 6.46 amp solar panels,
2 outback flexmax 80 charge controllers.
was told I can put these batteries in series or parallel.
more to learn.

 

[Darkstar]

Do you know if the battery is in the original BYD case or is that case one Techdirect uses to build into with BYD Cells and a BMS?

 

[tictag]

Thanks for the update! Do you have a specific query in mind?

 

[Steve_S]

I believe this is the one Michael is talking about: https://www.techdirectclub.com/byd-lfp-24v-5-kwh-200-ah-battery-pack-with-bms-130a-lifepo4/
Sadly, does not ship to Canada.

 

[michael d]

I believe this is the one Michael is talking about: https://www.techdirectclub.com/byd-lfp-24v-5-kwh-200-ah-battery-pack-with-bms-130a-lifepo4/
Sadly, does not ship to Canada.

yes, those are what I ordered. I want to go up to 48 volts. I am presently waiting for the order.

Hello.
You can connect these batteries in series or in parallel
If you still want to use the 24v without changing anything this pack will be fine. you may add up to 6 in parallel
You can connect the pack in series for 48v also total 2 in series and 4 in parallel
Let me know if you need more info

that was a reply I got from techdirect.

no exact question. my main concern will be charging them and connecting them in series and parallel. they are the ones on wheels in a case and supposedly have anderson plugs on them. more later when they are delivered. I ordered 4 of them.
I am planning to use them as stationary for whole-house project.

 

[michael d]

Thanks for the update! Do you have a specific query in mind?

I am wanting to know how to charge them. I want to charge them with the solar panels. and hopefully the outback flexmax charge controllers. I want to go up to 48 volts so more panels can be hooked up to each charge controller. I am reading a lot and watching lots of youtube videos.

 

[Darkstar]

yes, those are what I ordered. I want to go up to 48 volts. I am presently waiting for the order.

Hello.
You can connect these batteries in series or in parallel
If you still want to use the 24v without changing anything this pack will be fine. you may add up to 6 in parallel
You can connect the pack in series for 48v also total 2 in series and 4 in parallel
Let me know if you need more info

that was a reply I got from techdirect.

no exact question. my main concern will be charging them and connecting them in series and parallel. they are the ones on wheels in a case and supposedly have anderson plugs on them. more later when they are delivered. I ordered 4 of them.
I am planning to use them as stationary for whole-house project.

It's not real clear what the answer to this questions was. Could be interpreted to mean 2s4p could be built or it could mean only total of 2 single units in series. Anyone know for sure? Is this a limitation of the BMS they use?

 

[beansong]

Can't wait to hear more about these modules.

 

[Freddmc]

"Sadly, does not ship to Canada."

Have it shipped to Buffalo or Detriot or whatever US city/town is close to you and pick it up.

 

[Steve_S]

"Sadly, does not ship to Canada."

Have it shipped to Buffalo or Detriot or whatever US city/town is close to you and pick it up.

Simply NOT an option and never will be. I can get Summit Racing to ship me a complete ZZ4-350 Long Block Engine but batteries weighing 150 Lbs each nope.... what a pile of "dwaddle". Ironically, UPS has no problem delivering big battery packs of the same weight from China... pure trade genius there.

 

[michael d]

It's not real clear what the answer to this questions was. Could be interpreted to mean 2s4p could be built or it could mean only total of 2 single units in series. Anyone know for sure? Is this a limitation of the BMS they use?

not sure about BMS yet but they are shipped and hopefully arrive on Wednesday 1/22/20. I want to put them in series to get 48-volt bank, maybe 2 in series and 2 in parallel. not sure of details yet. I think they weigh like 190 lbs each so it should be a herculean effort to get it all done. I thought the 92 pound LF split phase inverter was plenty heavy (48volt 15000 watts but realistically 6000 to 7500 watts continuous) I am told. it will be a while before I can get it assembled. let you know as I get more pieces and parts set up.

 

[steviep19]

I purchased one of these batteries from TechDirect, about a week ago. So for I've been very happy with it. Very professional shipping, came on a pallet perfectly protected for shipping. I can vouch for the weight. I nearly threw out my back getting this up only 3 stairs....

 

[michael d]

I purchased one of these batteries from TechDirect, about a week ago. So for I've been very happy with it. Very professional shipping, came on a pallet perfectly protected for shipping. I can vouch for the weight. I nearly threw out my back getting this up only 3 stairs....

if you can share any details about charging or BMS, that would be great, trying to do as much myself as possible. thanks in advance for any help or suggestions.

 

[steviep19]

if you can share any details about charging or BMS, that would be great, trying to do as much myself as possible. thanks in advance for any help or suggestions.

Michael,

I only use the built in BMS for under/over voltage, current protection. The battery is in my basement and it's always about 65F in there. No easy feat, the battery weighs 200 lbs.

I set my Charge Controller in User defined mode, turned of temperature compensation.
I'm using 24v:

Charge Limit: 28.4
Float: 27.0
Equalization Time: 0
Low Voltage Disconnect: 22 v.

I have the charge controller hooked up to a RasberryPI, and it monitor the voltage. The charge controller seems to be properly charging to full, then going into float.

I have an older Lead Acid bank that I have attached as well. The Lead Acid bank stays disconnected and fully charge most of the time, unless needed.

When discharging at 25v I disconnect the Lithium bank, and connect the lead acid bank.
at 23v, a power supply connected to the mains, runs the load, until we have solar power again.

 

[GVSolar]

Stevep18: Interesting setup. Did you put your BYD directly into service - or do a charge/discharge first? My inclination is to do the c/d first to verify the batteries have been "waked up". I am proceeding with that on my units.
Also: I have read (and there are lots of opinions out there) that even a constant float voltage of 27 can cause LFP batteries to hit over 100% - which for the built in TD/BYD BMS is (3.75) or 30v (which is considered an overcharge). So you may be hitting them harder than you like. Or not - just a thought - any comments welcome.
And yes, they are dang heavy - I'm loving the wheels that TechDirect put on the units.

 

[GVSolar]

8S LFP LifoPo4 BMS
Detail	Min	Standard	Max
Single cell overcharge protection voltage	3.72 V	3.75 V	3.78 V
Single cell overcharge protection delay time	0.6S	1.0S	1.5S
Single cell overcharge recovery voltage	3.50 A	3.60 A	3.60 A
Recharge current	/	/	130A
Single-section equalization voltage	3.55 V	3.60 V	3.65 V
Single-section equalization current	35 mA	40 mA	45 mA
Single cell over-discharge protection voltage	2.15 V	2.70 V	2.80 V
Single cell over-discharge protection delay time	0.6S	1.0S	1.5S
Single cell over-discharge release voltage	/	/	130A
Discharge protection current	350 A	370 A	390 A
Charging high temperature protection	85'C	90'C	95'C

FYI: These are the TechDirect specs listed for the built-in BMS unit.

 

[steviep19]

GVSolar,

I based those figures off a generic Lifep04 video. I'm not the best at reading these data sheets. Do you think I should adjust the Float Voltage? It being winter here, if I do fill the battery, it's very late in the day, and it doesn't stay full for long, but come summer, that'll change.

And I did a full slow 4amp charge. Then waited until I saw the next day would be sunny, let the loads drain the battery overnight, then switched the loads to the Lead Acid bank, and fully recharged the Lithium battery to full. After that, I put it into normal service.

 

[GVSolar]

It all depends on whether you are looking for max storage or max life cycles (*from my reading of various specs). *Damage can be done to LFP by overcharging - and *battery life can be extended by keeping it between the knees (20% to 80%). Run a search on this forum using BYD, 200ah, and LifePo4 charging and you'll get some interesting discussions. (*according to folks that know more than me)

 

[GVSolar]

https://www.solacity.com/how-to-keep-lifepo4-lithium-ion-batteries-happy/
That's a good one to read.
And this posts is interesting - some thoughts about the used BYDs. There are more if you look around.

LiFePO4 Voltage Chart?

Looks like the article on Jason's website answered my question. I need a new battery charger.

diysolarforum.com

 

[nwillitts]

ok,question.
i will have my BYD prebuilt batteries on thursday.i want to wire them in serial,the connectors are Anderson which i have.
what would be the best way to interface the cables?wire one plug opposite of the other or regular wire and then combine the naked wire into serial?
any ideas?
Thanks in advance.