8 x BYD

[jasonhc73]

$250 Each. 8 total available.
Wichita Kansas.

I am going another route with my configuration.
In configuration and used regularly and safely daily.

I have 4 battery monitors with easy direct connect plug and play BMS cables that I made. All wiring on and in the battery is/are unmolested. I still have the OEM BMS that nobody knows how to use with them if you want them as well.

In 48V setups, I charge these to and float at 53.1V and disconnect at the inverter at 49.0V.


If you want to use them in 24V setups then divide by two.



The 4 "BMS" that I used all the MOSFETs died on me, made in china junk, but they are fine for monitors, and VERY light balancing, half amp each. All have Bluetooth connectivity and configuration.

All 8 are slightly more than 14 kWh of safe usable energy.

Call/Text - 3one6-37one-4224, or pm through the system.

 

[Maast]

So you're dumping them after all the work you put in. Kind of a shame but I totally understand. If I didnt have so much $ already in mine I'd go with something else too.

 

[jasonhc73]

There is just only so much you can do with them. I wanted 40 kWh when I ordered them, and I still do. 14kWh is all they have to offer. These have 4 dud cells in the 64 present, which dramatically lowers the total capacity.

They do work fine, and can be used just as they are, but I would recommend dismantling them and using only the good cells. If you were to use 48 cells in a 48v setup there would be about ~24-27 good usable kWh.

 

[jasonhc73]

I have new replacements ordered.
This is what two of the packs look like as of 21 October 2020;

I charge them to 53.1V and cut them off at 47.0V.
This is with an active balancer set at 1.0 amp balancing;


With active balancing, these are at least 20 kWh, probably more.
This is the active balancer that I am using;

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[Maast]

If I remember right you did parallel cell groups so the cell voltage spreads above are a little surprising, would have thought they'd average out a bit more.

I ended up with 3 bad packs out of the 13 I got. On one I had .8V on one cell right off the pallet so I just set it aside.

I had two more that tested out at 2.1kwh each, one had a bad cell 1 and another had a bad cell 7. On the first pack I'm going to attempt to replace cell 1 from the pack with a bad cell 7. It's on the end so it should make things a little easier.

I've also noticed several cells with a relatively high rate of self-discharge and/or high resistance when charging. Makes getting a good top balance really difficult (2-3 days of constant futzing per pack). I finally got so fed up that just yesterday I ordered eight RSP-100-3.3 power supplies so I can balance charge each cell in parallel up to 3.45V before the discharge test. Since I have 6 more coming in I think it'll be money well spent in time savings.

Mostly they've been testing out at 3.1kwh per pack, one was at 2.9kwh and another was 3.2kwh.

 

[jasonhc73]

If I remember right you did parallel cell groups so the cell voltage spreads above are a little surprising, would have thought they'd average out a bit more.

I ended up with 3 bad packs out of the 13 I got. On one I had .8V on one cell right off the pallet so I just set it aside.

I had two more that tested out at 2.1kwh each, one had a bad cell 1 and another had a bad cell 7. On the first pack I'm going to attempt to replace cell 1 from the pack with a bad cell 7. It's on the end so it should make things a little easier.

I've also noticed several cells with a relatively high rate of self-discharge and/or high resistance when charging. Makes getting a good top balance really difficult (2-3 days of constant futzing per pack). I finally got so fed up that just yesterday I ordered eight RSP-100-3.3 power supplies so I can balance charge each cell in parallel up to 3.45V before the discharge test. Since I have 6 more coming in I think it'll be money well spent in time savings.

Mostly they've been testing out at 3.1kwh per pack, one was at 2.9kwh and another was 3.2kwh.

I paralleled the packs, not each cell. If setup like DavePoz did, then I imagine I could get by with one balancer, as he did parallel each cell.

 

[Maast]

I paralleled the packs, not each cell. If setup like DavePoz did, then I imagine I could get by with one balancer, as he did parallel each cell.

I think you'd get a heck of a lot more capacity too - the regular cells would help out the weak ones, unless you had a 20amp active balancer I dont think it'd ever be able to keep up with moving charge to/from a weak cell under even a modest load/charge.
There's always one shitty cell in a pack but at least they're randomly distributed in the packs.

 

[jasonhc73]

~0.010 ~0.009 Delta Cell Voltage.
Balance update.

 

[jasonhc73]

Actively balanced.

 

[dochubert]

Hi,
Whatever happened with your batteries? Sold? Still using them?
I ask because I have a 48v bank of 16 of these that have been running my house now for 2 years or so. Mine charge up to a 56v float at up to 140a of solar charging. They stay fairly well balanced as I paralleled all the cells as David Poz did and have active balancers from Genetry Solar. I switch back to grid if I can't stay above 50v overnight so I'm baby-ing them somewhat, but am pleased with their performance and no issues so far.

 

[jasonhc73]

Hi,
Whatever happened with your batteries? Sold? Still using them?
I ask because I have a 48v bank of 16 of these that have been running my house now for 2 years or so. Mine charge up to a 56v float at up to 140a of solar charging. They stay fairly well balanced as I paralleled all the cells as David Poz did and have active balancers from Genetry Solar. I switch back to grid if I can't stay above 50v overnight so I'm baby-ing them somewhat, but am pleased with their performance and no issues so far.

I sold four and use four.

The ones I use are in my cargo trailer. They have a total of about 5 kWh in a 24v setup. I charge them with only solar about once every 8 or 9 days.
If the trailer wasn't parked under the tree the batteries would remain fully charged all the time.

Here is the trailer with the 4 BYDs in use.

Another Cargo Trailer setup.

This is now officially a legitimate sickness. My 4th off-grid system: The players: This setup is actually cheaper than going with a PWM Hybrid all in one unit 48V unit. I have AC input to charge the 48V batteries with shore power. (The 21.99 charger) A way more than I will use MPPT battery...

diysolarforum.com

 

[dochubert]

Glad you got to use the byd batteries. I'm happy with mine.
Considering it's a trailer, and you likely drive it around sometimes, I would think the weight of the batteries would be of some concern. The first eight I bought were the kind that didn't have the heat sinks and fans. About 125 lbs apiece. The second eight I bought were the same as yours with fans/heatsinks. About 160 lbs apiece. So 35 lbs of extras times 4 batteries - 140lbs.
There was a video on youtube where a guy broke his down to cells. Watching it I realized I could make mine lighter and smaller by removing the 'extras'. The left side of the picture I sent above shows my modified set after removing heatsinks, covers, fans, bms', internal busbars, and those wonky positive and negative posts they come with. Before stacking them I attached a 14ga wire to each cell and connected them all to a terminal block I added on the front of each battery. After stacking, used the terminal blocks to parallel all cells and connect to balancer. Used some of the internal busbars to make my positive and negative busbars. Bolted them to existing threaded connections - better conduction and more surface area contact. Plus saved a lot on battery cables!
My batteries are in a basement with fairly constant temperature so the fans weren't needed anyway.

 

[jasonhc73]

Glad you got to use the byd batteries. I'm happy with mine.
Considering it's a trailer, and you likely drive it around sometimes, I would think the weight of the batteries would be of some concern. The first eight I bought were the kind that didn't have the heat sinks and fans. About 125 lbs apiece. The second eight I bought were the same as yours with fans/heatsinks. About 160 lbs apiece. So 35 lbs of extras times 4 batteries - 140lbs.
There was a video on youtube where a guy broke his down to cells. Watching it I realized I could make mine lighter and smaller by removing the 'extras'. The left side of the picture I sent above shows my modified set after removing heatsinks, covers, fans, bms', internal busbars, and those wonky positive and negative posts they come with. Before stacking them I attached a 14ga wire to each cell and connected them all to a terminal block I added on the front of each battery. After stacking, used the terminal blocks to parallel all cells and connect to balancer. Used some of the internal busbars to make my positive and negative busbars. Bolted them to existing threaded connections - better conduction and more surface area contact. Plus saved a lot on battery cables!
My batteries are in a basement with fairly constant temperature so the fans weren't needed anyway.