LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

[Hoopla]

OK here goes with my first system design question.

Can anyone please help me with identifying the poles on the looped signal cable going to and from the batteries and the Victron Ve-Bus-BMS OR alternatively how I would go about testing to make that identification?

As you can see by the picture Victron use a looped signal cable with 8mm round 3 pole male and female plugs. The BMS Circuit Board on each Battery Cell is daisy chained or parallel connected to the Main BMS. I assume there is a single voltage signal wire via one(1) pole in each cable and that signal connection is not polarised In the normal manner. That means the other two (2) poles must belong to the looped battery temperature signal connection to the thermistor on each BMS circuit board and is polarised, hence the male and female plugs.

Victron naturally can’t help me with identifying these signal poles as it facilitates using 3rd party/Non-Victron batteries.

I’m not using a generic BMS as I want to utilise the proprietary Victron "data connectivity" between the BMS and other Victron gear and be able to fully program connect/disconnect functions direct to charging and load sources themselves (not via relays) as the second line of defence after alarms. The final and third line of defence is the BMS’s charge and load relay disconnects to the dual positive bus.

Thanking you in anticipation.

[mdsilvers]

Hello everyone. This thread has been excellent. I need some help. I'm having a DEVIL of a time finding two relays/contactors for my new setup.

My design is located here for reference.

I am trying to source:

12v Coil, 50amp 110VAC NC (or DPDT)
12v Coil, 100amp VDC NC (or DPDT)

You can see my diagram. They are listed at Relay 6R & Relay 9R, highlighted in yellow.

Thanks in advance. I leave in two weeks back to our boat in Fiji, so I'm trying to source as much as possible here in the US.

PS

If you see anything that looks whacky on my design, please don't hesitate to tell me....

[scaredycat]

Here is a good source:
Relays | Mouser

[mdsilvers]

Originally Posted by scaredycat

Here is a good source:
Relays | Mouser

I've used this source and not been able to find the required relays...

[offpist]

Originally Posted by mdsilvers

Hello everyone. This thread has been excellent. I need some help. I'm having a DEVIL of a time finding two relays/contactors for my new setup.

My design is located here for reference.

I am trying to source:

12v Coil, 50amp 110VAC NC (or DPDT)
12v Coil, 100amp VDC NC (or DPDT)

You can see my diagram. They are listed at Relay 6R & Relay 9R, highlighted in yellow.

Thanks in advance. I leave in two weeks back to our boat in Fiji, so I'm trying to source as much as possible here in the US.

PS

If you see anything that looks whacky on my design, please don't hesitate to tell me....

Both Mastervolt and Victron has combined charger/inverter solutions that also have an separate input for shore power and generator.

I use the Mastervolt Mass Combi Ultra 12/3000-150 (230 V)
When connecting shore power it automatically switches to shore power.. And same when you start the generator it automatically switches to generator.
It waits some seconds to make sure the specs are within.

No flipping switches or relays needed.

There are other great benefits also.
You define the maximum fuse on shore power and on generator, and the the inverter makes sure you never blow the fuse.

Lets say you set the shore fuse to 10A. (230V)
If you need 16A for some minutes for example to start an washing machine it will reduce the charging, if that is not enough it will take the extra power from the battery.

So the inverter is synchronized to the shore power/generator, and can help with extra power if needed.

Also you can setup the lithium charging program just the way you want.

It also have an second AC output that is only active when running generator or shore power, great for electronics you don't want to run on the inverter.
Hot water heater for example.

It even has an build in MPPT solar charger!

I know Victron has an similar solution.
Not sure if it comes in 110V, but should check it out.

[botanybay]

I am running a Victron Quattro 8kva (24V) 230V inverter and use it exactly that way.

Generally when running on dock power all of the power is converted to DC (using a Skylla-I charger and auto-switching isolation transformer). This means that the boat is running 230V/50hz

In this configuration both 230V busses are on the inverter only output, I do need to add a load sheading solid state relay for the hot water heater and air conditioners so that if dock power goes away these don't pull the batteries down.

I can also take the output of the isolation transformer and run it directly to one of the inputs of the inverter charger. This means in Europe I see 50hz/230V with 16A of capability, on a US 208V dock I get 60hz/208V, on a US 240V dock I get 60hz/240V, and on a US 120V dock I get 60hz/240V.

If the generator kicks on the inverter will prefer the generator input and shift in all cases to 50hz/230V.

Away from the dock, the hot water heater, air conditioners, and washing machine are on the secondary output of the inverter. These are not powered on unless the generator input is active.

The really nice piece of this is:
a) everything is automatic and internal to the inverter
b) the shore power input is never overloaded as the inverter will support the input load and keep it below the isolation transformer or shore power limit
c) the generator input is never overloaded

Really love the Victron gear, their support has been exceptional.

[mdsilvers]

Originally Posted by offpist

Both Mastervolt and Victron has combined charger/inverter solutions that also have an separate input for shore power and generator.

I use the Mastervolt Mass Combi Ultra 12/3000-150 (230 V)
When connecting shore power it automatically switches to shore power.. And same when you start the generator it automatically switches to generator.
It waits some seconds to make sure the specs are within.

No flipping switches or relays needed.

There are other great benefits also.
You define the maximum fuse on shore power and on generator, and the the inverter makes sure you never blow the fuse.

Lets say you set the shore fuse to 10A. (230V)
If you need 16A for some minutes for example to start an washing machine it will reduce the charging, if that is not enough it will take the extra power from the battery.

So the inverter is synchronized to the shore power/generator, and can help with extra power if needed.

Also you can setup the lithium charging program just the way you want.

It also have an second AC output that is only active when running generator or shore power, great for electronics you don't want to run on the inverter.
Hot water heater for example.

It even has an build in MPPT solar charger!

I know Victron has an similar solution.
Not sure if it comes in 110V, but should check it out.

Thanks for the info. The issue I am trying to solve is not an issue with shore power or generator power...it is turning 'off' the charger if there is a HVC. This is accomplished by - at this point - turning off the input of AC to the Mastervolt. It is not related to switching between shore or generator - but shutting all power off so the charging will cease.

If I could find a way to do this without putting a relay between the Mastervolt and AC power source I would...but so far I have been stumped...

Thanks for taking the effort to reply.

[Hoopla]

Originally Posted by mdsilvers

Thanks for the info. The issue I am trying to solve is not an issue with shore power or generator power...it is turning 'off' the charger if there is a HVC. This is accomplished by - at this point - turning off the input of AC to the Mastervolt. It is not related to switching between shore or generator - but shutting all power off so the charging will cease.

If I could find a way to do this without putting a relay between the Mastervolt and AC power source I would...but so far I have been stumped...

Thanks for taking the effort to reply.

Hi Mark. I see no answers to my Victron BMS question above and your Victron answers don’t address your question. The joy of interweb forums. I hope this helps.

Using Victron software VEConfigure 3 and a thing called Ve-Bus BMS Support a Victron Multi or Quattro can be controlled directly by the charge and load disconnect outputs from a 3rd party BMS. Very useful for controlling equipment direct, particularly useful dealing with these Inverter/Charger devices sharing a common DC bus and without the need for an AC relay for Chargers and a DC relay for Inverters. However they do need to be a recent Multi/Quatro types that have auxiliary inputs….firmware version 19 (first 2 numbers on the label on the processor IC on the control board).) onwards I recall.

Note: Unless you have a Victron BMS and Victron A C Detector your MultiPlus or Quattro won't automatically restart when AC supply becomes available, in case it has been switched off by the BMS due to low cell voltage. Probably not such a fool proof feature anyway and manual intervention preferable.

However BMS Bus Support feature won’t work with a Victron Centaur Charger your intending to use as it is not Ve-Bus enabled. I don’t know whether you have purchased the Centaur or not however I would steer clear of them. They are probably the only Victron product that doesn’t have a good reputation (the AC side stinks), they only have dip switches and can’t be configured for LFP.


On the other hand their Phoenix is an excellent charger but their capacity is limited and this feature wont work either. For Lithium you are better off getting a Multi to obtain the higher charge capacity and utilise the above BMS direct switching feature. If you prefer a separate inverter the Multi inverter can be turned off.

I don’t know enough about Mastervolt Inverters and Chargers to say whether they have a similar thing to this Ve-Bus BMS Support direct switching? The two companies tend to mirror each others features sometimes so possibly yes?

Cheers

[botanybay]

I am running the skylla-I charger as part of my system from victron. Very lightweight, 100 amps at 24v. Canbus enabled. Talks to the color control GX nicely.

Only limitations is there is only a 24 v model and the input voltage range is 180 to 260

I have victron's auto ranging isolation transformer in front of it so I can use anything from about 90v to 260v 50/60 hz.

[gael]

Originally Posted by botanybay

I am running the skylla-I charger as part of my system from victron. Very lightweight, 100 amps at 24v. Canbus enabled. Talks to the color control GX nicely.

Only limitations is there is only a 24 v model and the input voltage range is 180 to 260

I have victron's auto ranging isolation transformer in front of it so I can use anything from about 90v to 260v 50/60 hz.

Just FYI, I run a skilla 50Amp charger on my 2x 26 / 130Ah banks since 2010, living on board.
The skilla is configured as a 28V voltage supply and let the 50Amp current clamp limits the charge current. This goes in a FET splitter (also Victron) and then in the banks.
So this is not a Victron specfic way to load LiPofe bat'. but so far so good.
cheers

gael

[Colin A]

Originally Posted by mdsilvers

Hello everyone. This thread has been excellent. I need some help. I'm having a DEVIL of a time finding two relays/contactors for my new setup.

My design is located here for reference.

I am trying to source:

12v Coil, 50amp 110VAC NC (or DPDT)
12v Coil, 100amp VDC NC (or DPDT)

You can see my diagram. They are listed at Relay 6R & Relay 9R, highlighted in yellow.

Thanks in advance. I leave in two weeks back to our boat in Fiji, so I'm trying to source as much as possible here in the US.

PS

If you see anything that looks whacky on my design, please don't hesitate to tell me....

I Believe Schneider makes a DPDT contactor that would word for you but a 12VDC coil may be tricky (most are 24VDC but you could run a small converter) check out there telemecanique line try the tesys D line I know we have used them before.

For 100 amp DC you could try Gigavac, or albright but I'm not sure either offers NC versions. I believe PC&S in NJ may offer DC contactors as well.

[ardoin]

Looking into adding a wind generator. What's a good charge controller for LIFEPO4 for a wind generator? It should have a diversion load as well.

[mdsilvers]

Originally Posted by ardoin

Looking into adding a wind generator. What's a good charge controller for LIFEPO4 for a wind generator? It should have a diversion load as well.

I am using the Superwind 350 with their controller. Here is the key, you need to be able to divert as you mention the load. This controller came with two power resistors, that allow me to divert easily. I use the temperature sensor circuit with the 2kohm resistor. Break the circuit with a relay (HVC Alarm from BMS) and load is diverted. See the diagram here....

[Hoopla]

China has just devalued its national currency to its lowest rate against the US dollar in almost three years....that will put pressure on LFP battery prices.

[Cottontop]

A fully-realized residential system:

JuiceBox Lithium-Ion Solar Energy Storage Systems