Path: ...!news.roellig-ltd.de!open-news-network.org!weretis.net!feeder8.news.weretis.net!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail
From: Klaus Vestergaard Kragelund <klauskvik@hotmail.com>
Newsgroups: sci.electronics.design
Subject: Re: Looking for turn-key BMS system
Date: Thu, 3 Oct 2024 12:32:01 +0200
Organization: A noiseless patient Spider
Lines: 43
Message-ID: <vdlrr0$3mrkc$1@dont-email.me>
References: <vdjgrm$38c4n$1@dont-email.me> <vdkhjt$3dbi8$3@dont-email.me>
 <vdlnf8$3lqgo$1@dont-email.me>
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Injection-Date: Thu, 03 Oct 2024 12:32:01 +0200 (CEST)
Injection-Info: dont-email.me; posting-host="d4ed602a376608fa3f63c006500e76aa";
	logging-data="3894924"; mail-complaints-to="abuse@eternal-september.org";	posting-account="U2FsdGVkX1/9i1urxn489oUK2HsMo8pajauPvZ6Ya4U="
User-Agent: Mozilla Thunderbird
Cancel-Lock: sha1:3Nf54bzYFZT6ApLCjbxKIcvZ7UU=
In-Reply-To: <vdlnf8$3lqgo$1@dont-email.me>
Content-Language: en-US
Bytes: 2688

On 03-10-2024 11:17, Klaus Vestergaard Kragelund wrote:
> On 03-10-2024 00:31, Lasse Langwadt wrote:
>> On 10/2/24 15:12, Klaus Vestergaard Kragelund wrote:
>>> Hi
>>>
>>> One of my clients is looking for replacing existing HW, 2 200Wh 
>>> battery modules, which each has a BMS controller, that monitors and 
>>> balances 12 lithium ion cells (4 series connection of 3 parallel 
>>> cells). Each of the modules has SOC output in the form of LEDs.
>>>
>>> Beyond that, the overall system has a BMS controller that is powered 
>>> from either 24VDC (grid connected) or from the batteries. This BMS 
>>> controller also has SOC, with a connected display.
>>>
>>> The client would like a turn-key solution, so minimal NRE due to low 
>>> volume.
>>>
>>> I am looking for a supplier of finished batteries with BMS and also 
>>> BMS controller. Perhaps one of you guys has worked with this? (need a 
>>> stable supplier)
>>>
>>> Client is based in the EU.
>>>
>>> Thanks
>>>
>>> Klaus
>>
>> https://www.victron.dk/ ?
> 
> Looks good, they have a lithium battery with internal BMS at resonable 
> price.
> 
> No State of Charge (SoC) though for the battery. Is it possible to get 
> rough SoC from a lithium battery by voltage sensing only?

A number of hits online says that SoC is difficult to determine for a 
Lithium battery purely from the voltage.

But for the cell I am using, the datasheet seems to disagree (if 
compensated for temperature)

https://electronicsdesign.dk/tmp/ur18650.pdf