Solar PV battery options

Jonathan

https://www.boards.ie/discussion/comment/120631136#Comment_120631136

Why did you move from 16S to 15S? Did you get stung with a bad batch of low capacity cells?

graememk

With the JK you need an additional stuff to do the translation from it's rs485 to the CAN the inverter expects.

It's easier leaving the dryness being the one that talks and doesn't even know about the extra battery

unkel

https://www.boards.ie/discussion/comment/120631201#Comment_120631201

No need to do any of that. The JK BMS will mind your EVE / CALB cells and the BMS inside the Dyness will protect its own cells. The packs function independently of each other.

Another benefit is if you need to do some maintenance on either pack, you can disconnect it and the other pack will just keep working too. Easiest I find is with a battery marine switch with connections for two batteries, so you can have both off, either 1 on, or 2 on, or both on

unkel

https://www.boards.ie/discussion/comment/120631220#Comment_120631220

The opposite, kind of 😁

I got some more batteries than I needed - cheaply from boardsies who weren't too happy with the capacity of some of the cells - and they were sitting here unused. If I were to get 5 more I could go one down in series, but one up in parallel. So that's what I did on Sunday.

unkel

@graememk - "It's easier leaving the dryness being the one that talks and doesn't even know about the extra battery"

I prefer where none of them know about each other or talk to each other and none of them make any decisions on their own except for protecting battery cells 😂

steamdave

I will be installing a replacement pv system in a few months' time. New system will be 10 panels SSE + 6 panels WSW = 6.4kWp. I will be getting a new 5.1 kWh battery also.

There is a chance that the old battery (6 month's previous use) may be salvaged, but I won't know until after the new system is installed. Is it possible to have too much battery power installed? I hope that there will be sufficient power in the dark months to charge up the battery, no problem in the summer months. I don't have an immersion heater so no Eddi nor an EV (for a few years).

I'm on a smart meter but not on a time of use charge plan (level 24 hour rate) because my electricity usage would not justify the change of plan. It would presently be uneconomical to charge the battery from the mains.

So do I go with the 5.1kWh battery or try and use the second battery for a total of 10.2kWh?

Dave

Fingleberries

If the old battery still works and plays nice with the new one, and you have room for them both, it could be worth it to keep both together, means that you could potentially shave more peak usage away during darker months (charge it during off peak hours) - that's what I'd do.

If you don't think they'll play well together, you could probably look to sell the old one.

steamdave

Both batteries are from the same provider and are equal in all respects - at least they were when the original one was new. Don't know if the heat from the fire has damaged the old one. It was not directly impacted by the fire, just that it got a 'bit' warm.

It was suggested that they should be wired in parallel so that if there is any drop off in performance of the old one, the new battery would not be compromised.

My only worry about putting in two batteries is that if they cannot be charged during the winter months, their performance/capacity may be degradd before time. Charging from the mains is not a goer because I am not on a time of use electric plan and my way of living would not be of any benefit to change.

Dave

unkel

Why can't you just use the old battery and not get a new one? Would save a fortune. And what's the reason behind the upgrade of your PV system, are you going up in size? What's the make and model of the old and the new inverter?

con747

https://www.boards.ie/discussion/comment/120667790#Comment_120667790

House fire iirc so be an insurance replacement.

unkel

Insurance normally just pays out. You can then do with the money what you want. Or is it different in this case?

randombar

https://www.boards.ie/discussion/comment/120558972#Comment_120558972

Trying to sort this one out.

Basically copied the code from esp32-heltec-balancer-ble-example.yaml

Clicked edit on the device in ESPhome, pasted it in, changed the mac address but no joy:

"ERROR Error resolving IP address of heltec-balancer.local. Is it connected to WiFi?"

Might give it another go in the morning but wondering if I was going the right way.

graememk

https://www.boards.ie/discussion/comment/120668561#Comment_120668561

did you have your secrets.yaml with your wifi details in it?

randombar

Yup

randombar

https://www.boards.ie/discussion/comment/120668574#Comment_120668574

Abort!!! Turns out I was using ESP8266 instead of the ESP32 which doesn't have bluetooth. Apologies.

graememk

https://www.boards.ie/discussion/comment/120670104#Comment_120670104

That would do it! 😂

SlowBlowin

As I needed some busbars for the CALB cells in a hurry I made up a press die to stamp them out of 1/2 inch copper pipe. It put a double bend in to help with heat expansion and small size adjustments.

If anyone is stuck for busbars and needs something in a hurry drop me a PM.

randombar

That’s class. Fair play to you.

poker2k9

Question;

Are most folks on here able to charge their batteries from PV rather than from the Grid?

I have quotes for either type of these batteries but finding it hard to get responses from suppliers if they are AC coupled or not.

*Dyness BX51100 5.12 KWh

*Puredrive Energy PSII 5kWh

Also, any input on which of the two batteries above I should go for other then Dyness being cheaper?

unkel

You are mixing a few things up here. Any battery can be charged from any source

There are two different types of setup, you can have a hybrid inverter that can charge / discharge your battery (from the grid if you want) and has solar panels connected to it. The other type is a battery only inverter with no solar panels connected to it. You can charge this from the grid if you want, but it will also have a CT clamp on your separate solar inverter, so it knows to charge your battery (from PV) if you produce more PV than you are using

poker2k9

https://www.boards.ie/discussion/comment/120809545#Comment_120809545

Sorry i did mix that up and wanted to say charging batter from grid (preferred) & pv (excess)

But your explanation does give some insights, thanks!

con747

https://www.boards.ie/discussion/comment/120810213#Comment_120810213

I went with the Puredrive because it had a 10,000 cycle 10 year warranty and I think has a lower depth of discharge level and have had no issues with it.

championc

https://www.boards.ie/discussion/comment/120809488#Comment_120809488

You need to look at DISCHARGE specs

A 5kWh battery doesn't necessarily discharge at 5kW

jones

Folks I'm sure this has been asked before but how do the Huawei batteries hold up compared to Solaredge?

I'm going with 2 Huawei units to make up 10 kw as opposed to 1 Solaredge (9.7). I like the expandability of Huawei but am I missing anything by not going Solaredge? The Solaredge system was over 2k dearer and the battery had to be placed outside on the wall so I went with Huawei.

DrPhilG

Having some odd behaviour with my system today.

I have the Neey balancer in play, kicks in when a cell passes 3.5v and the bms will halt play if the cell passes 3.7v.

Very strong bursts of sun today so one cell has occasionally hit 3.7 but rather than the battery stopping and the excess going to the car, the inverter is reporting a fault and shutting down completely.

Any thoughts?

unkel

Your inverter is only doing what your BMS is telling it to do. Looks like a high voltage alarm. What the NEEY is doing is irrelevant to your issue. What BMS?

DrPhilG

https://www.boards.ie/discussion/comment/120846808#Comment_120846808

ZEVA.

Behaving again now. I powered it all down and rebooted and it's bang on.

unkel

https://www.boards.ie/discussion/comment/120846873#Comment_120846873

Always reboot first before ringing the helpdesk 😁

Glad you got sorted!

randombar

Hi Folks,

What kind of prices are we talking about for non DIY batteries these days?

Thanks.

unkel

https://www.boards.ie/discussion/comment/120848224#Comment_120848224

You giving up on your DIY battery altogether?

I guess it depends what type of battery and whether you buy new or second hand. I just sold a 5kWh nearly new standard Chinese no name LiFePO4 pack with Seplos lookalike BMS for €895 but if you buy a similar capacity pack from an installer, it would easily be 3 times that price for them to come over to your gaff and spend 30 minutes installing it.