question

danielp avatar image
danielp asked

Help: Does this set up look ok?

Hi Guys.

I'm brand new to this community. Just wondering if anyone can help me out?

I'm getting rid of my AGM batteries for Lifepo4. Whole new world for me. Below is a rough sketch of what i will be doing but i haven't added the active equalisation board in the drawing. I assume i can change settings and safety settings in my easy solar for over charging and low temp. I have battery sensor and bmv712 battery monitor.

Dont laugh at my 1000amp hour system on 12v. Too late now to change.

Any advise or help would be great? This is just a weekender property.

Thanks


Lithium BatteryVictronConnectAssistants
image0.jpeg (1.3 MiB)
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

4 Answers
Matthias Lange - DE avatar image
Matthias Lange - DE answered ·

What BMS do you have?

1 comment
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

danielp avatar image danielp commented ·

Hi its a 200 amp not sure of make. Im waiting on my cells and bms to come in the next few weeks. My supplier is supplying the bms but from what i remember it looked abit crappy lol. So might get myself a daly 200amp common port

0 Likes 0 ·
Paul B avatar image
Paul B answered ·

Hi There and welcome to the forum.

As a suggestion to start with I would suggest that you join 2 x 500A/H cells in Parallel thus making one cell of 1000A/H then connect the 4 x 1000 A/H cells in Series. This then makes ONE big 12 Volt Battery. It also cuts down on the number of BMS cell balancers that are needed. thus reduces cost.

The Inverter charger only controls the Charge and float voltage of the WHOLE battery and the emergency total Low voltage cutoff.

Your BMS should be doing everything else.


IE there should be a large cutoff relay (or a inverter control system to turn load or charge off).

This relay is turned OFF if any cell goes out of spec Ie Hi or low voltage or the Temp is out of spec for any cell.

The Inverter charger does NOT control the individual cells your BMS does that

2 comments
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

danielp avatar image danielp commented ·

Thanks for info. I understand the inverter charger only controls the charge and float.

You say large cutoff relay.... wouldn't the bms (daly 200amp) turn off high overcharge?

0 Likes 0 ·
danielp avatar image danielp commented ·

Sorry again for my drawings. In regards to your first suggestion is this what you mean? Due to space issue i have to stack them upwards.

0 Likes 0 ·
img-2981.jpg (1.3 MiB)
Paul B avatar image
Paul B answered ·

Here is a VERY ruff diagram without any breakers or fuses etc and without the BMS boards installed. and also does not have your super cap installed as well

there are lots of different BMS units out there this is JUST one as a example for the 123 smart units there are 4 boards in a 12 volt system.

(NOTE using a VE-BMS unit this way is NOT recommended or supported by VICTRON ENERGY)


this diagram is just to provide a idea and is NOT complete


I would also sugest a Venus GX device or a Victron Color control CCGX not shown below


1597568685469.png (75.9 KiB)
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

klim8skeptic avatar image
klim8skeptic answered ·

Hmm.. 1000ah of lithium is pretty expen$ive.

It is probably worth $pending some money on decent and appropriate battery protection (BMS), simply because one small failure in monitoring can snafu your entire battery.

A lithium BMS should comprise,

Cell balancing.

Cell hi/low voltage monitoring/cut out.

Battery hi/low voltage monitoring/cut out.

Cell low temp charge cut.

Paul B has made some good points.

1 comment
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

danielp avatar image danielp commented ·

Hi and thanks,yes expensive lol thats why i want to get it right. So many bms to choose from PaulB mentions smart 123 i also seen a daly 250a smart bms last night while i was searching around seems like it had all them features.thanks

0 Likes 0 ·