Search results

I ended up importing the batteries and inverters myself and did a group buy on a container of panels. Everything has been working well.

It is an old thread that got revived for a couple of posts. It will probably go silent again.

Very true, thanks for catching that.

Yes, each battery is different due to process differences/improvements and sometimes due to how they present the data in the datasheets. The Hithium 280's do have a 10,000 cycle life, but they rate it down to 70% capacity instead of 80%. The EVE LF280K is 6,000 cycles for 80% capacity at 25C...

The datasheet just says that the capacity is typically 285 Ah, but the minimum is still 280 Ah at 25 +/- 2 degrees C. Later in the datasheet is less clear since a 1C discharge rate can result in 97% of capacity (271.6 Ah) and may take 3 cycles to even meet that. All-in-all, if you are...

Oh, I did not know about that. That is not good at all. To be honest, 2 Ah (about 0.7%) can easily be lost due to cable losses or uncalibrated equipment. Most current sensors are +/- 3% over temperature and even precise ones are often +/-0.5%. Without calibrated test equipment it is very...

Right, and this thread was for someone in Australia so that is a bit off topic. No reason to be rude to suppliers. Shenzen Luyuan has provided great service to many people here.

Did you have a question or something to add? You may also want to take a look at this thread: https://diysolarforum.com/threads/jk-bms-can-bus-comms-now-possible-for-inverters-that-support-goodwe-and-pylontech-batteries.48963/

Ah, I wasn't aware they built that board! Thanks for that. Looks like Daly has finally stepped up their game. I had talked to them about 1.5 years ago about adding the Pylontech protocol to their batteries. I guess they got enough requests to finally add it!

Which interface board are you using?

Nice solution sebdehne. As an optimisation, if you have the CAN or RS-485 Daly BMSs, you can configure each one with a different ID and use a single CAN-to-USB or RS485-to-USB converter to talk to all of them.

Ah, are you with MainPower?

Here is the CAN protocol for the JK BMS. It should send the CAN messages after power-up according to the protocol, but you will need to make sure you have your CAN receiver set to 250 kbps and have the 120 ohm termination resistor on, otherwise it may stop sending messages. Serial should work...

DPD means that Seplos should be responsible for the insurance for any damage involved, so they should ship you a new one in my opinion. That said, most of the damage looks to be cosmetic. You may be able to straighten it out with a hammer and a punch and repaint. If you don't want to paint...

Correct, the signal that you are trying to measure (battery voltage) is being corrupted by the noise in the measurement system. Often people will just average the noise, but this assumes that the noise distribution is even which it may not be depending upon the source of the noise. The battery...

I haven't gone into this level of depth for charge analysis and haven't looked into the chemical reaction to the current pulse and then relaxation. However, with 6 mV of measurement error, I do wonder if some of what you are seeing is due to the noise distribution of your measurement circuit...

To be fair, the USD10 was probably due to bank fees taking their cut if you paid by bank transfer. As for the shipping cost, they should have put the actual cost on there when they finalised the order, but sounds like they were being lazy. Costs for BMSs should be pretty fixed as well since...

Non-technical resellers do not provide any real value for DIYers. A bit of shame since Seplos has a good potential market with the case kits.

Once battery packs are connected in parallel, the current flow due to loads should be self balancing. Weaker cells will have a higher internal resistance and will hence have a lower current flow compared with stronger cells. Cables should ideally have equal resistance, but if they do not, then...

You may be overthinking it. You only turn the BMS MOSFETs off for protection for over-voltage, under-voltage, and over-current. You also typically instruct the inverter (over CAN or RS-485) what the charge current and voltage will be to prevent over-charging and a minimum SOC where it will...

Some MOSFET drivers (e.g Infineon 1ED44176N01F) have over-current protection included as long as you feed it a current signal from your current shunt circuit. The other option is to use a current sense amplifier (e.g. INA228) that has an alert output which you can use to disable the MOSFET...

Nice image captures. You will end up with power being dissipated by the body diode of the MOSFET that is off, so you have to make sure the heatsink can handle the thermal load. I would suspect that most over-current (short-circuit) circuits are hardware based (instead of microprocessor based)...

Great, thanks for confirming that. I had a look at some of the industrial battery rack BMSs and they normally have a pre-charge circuit consisting of a resistor and MOSFET to pre-charge inverter input capacitors and it also allows them to disconnect batteries when connected in parallel if the...

Thank you @antera -- I'm really sorry to hear about your issues and hope that Seplos comes through in the end. It looks like the case design is solid, but I'm really surprised the BMS is in as bad of shape with quality issues, etc. The parts on the board are not expensive, so they should have...

@antera - was this issue ever resolved? I'm a bit concerned as I was getting ready to talk with Seplos for a 100 pcs order for some industrial packs, but will spend some more time looking for alternatives.

First, figure out if you need the US version (120V 60 Hz split phase) or EU (230V 50Hz), then take a look at the resellers on Alibaba or apparently down in Mexico. If you are buying more than a pallet load, you can buy direct from Deye.

I did not, but I also purchased 8 inverters. If you are just after 1 or 2 of them, then it will probably be easier through a reseller.

I did not. While I was waiting to see how gramos100 got along, I ended up buying some panels from a friend, inverters from Deye directly, and batteries from Amy @ Shenzhen Luyuan. Everything worked out fine. Batteries required some extra paperwork and delays due to being class 9.

It doesn't look like it. Most of the Smart BMS manufacturers seem to be targeting electric scooters, so solar inverter support is low on their priority list. It gets more complicated if you have multiple battery packs where each one has a BMS since the values from each BMS need to be...

The CAN and RS-485 protocols are listed here: https://github.com/NEEY-electronic/JK/tree/JK-BMS The CAN protocol doesn't look promising since it doesn't match the Pylontech protocol which is the defacto standard for inverters like the Deye. JK CAN protocol message IDs are 11-bit IDs with...

I am assuming this current limit is just for the initial battery connection when two packs are at different voltages? I would think connecting them with a resistor and allowing the voltage to equalize would eliminate needing to have the parallel modules. Anyone have experience with that?

Good to hear. I purchased cells from Amy Wan and used a local company for import into New Zealand. Amy delivered them to the port as expected, but there were multiple delays due to hazardous cargo delays. The captain / shipping manager on each ship decides how much hazardous cargo they will...

Yes. @gramos100 shared the values he was using on another thread and the batteries appeared to be disconnecting at a lower voltage than expected, so it may also be caused by some cells being out of balance. The general rule is that the batteries should be configured to never overcharge and do...

The charging current going to the batteries should go to 0A when the end-of-charge voltage is reached. Nothing should shutdown just because the batteries are full. Initial setup is sometimes very difficult, so keep working on it and solving the problems one at a time.

There is no "dump load" needed for PV panels. If you don't pull any current from the panels then the voltage will just go to the Voc (open-circuit voltage).