question

ogcampers avatar image

Is this wiring diagram for a Lithium Camper scheme correct?

Hello,

I am in the middle of making an elektrical schematic for on of my camperbuilds. In this build I would like to use an lithium battery.


I am using an Liontron 130Amp battery with build in BMS

Victron Smartsolar 100/20

Victron Multiplus 800VA

Victron BVM 712 Smart

Victron Battery Protect 3 x

Votronic B2B charger

300 watt Solar panel


To protect the LifePo4 battery I am using 3 x an Battery Protect in this scheme.


My question is: is this overkill and if not are they in the correct position?


The Votronic B2B charger wich I am using is not working via an battery protect, because it has a build in safety system and it will cut of charging when the temperature or charging levels are getting to high.

Because I am not using an Victron battery :( I can't use an Victron BMS or Mini BMS or VE-BMS etc.


Now I found another build online, although this is not with an LiFEPo4 battery they are just using 1 battery protect. Mounted directly on the battery +30, I thought an battery protect could only work 1 way, so either charging or de-charging protection? Does this build on the picture below mounted correctly?


I am looking forward to an reaction! :)

Thank you, Maarten

Lithium BatteryBattery Protectcampervan
victron-lithium.png (129.6 KiB)
schema-noblevans.jpg (202.5 KiB)
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This biuld may cause the BP to be Damaged, as the BP IN to OUT is the direction of flow and is fine for the inverter however when the systems charges it will cause a flow OUT to IN and this may damage the BP.

This install should have one more BP installed for the charging side. All chargers to IN and the out going to the battery.

Thanks, I understand now that BP can only be used one way. So in case of this Inverter wich is a charger as well and using the same cables for it. So it will be not right to mount an BP there.

Wkirby told be in an reply below. That the inverter can be controlled remotely. Only I am not exactly sure how yet. :)


Here is the manual:

https://www.victronenergy.com/upload/documents/Manual-MultiPlus--500VA-1200VA-EN-NL-FR-DE-ES-IT.pdf

In section 4.4.3 it explains remote control and then in section 5.4.1 it explains how to set the DIP switch for remote control operation.
In the Appendix on page 133 there is an illustration of the connections.

Use dry relay contacts to signal the devices. It is possible for example to have the BMV-712 relay wired to the remote contact on the MultiPlus to disable discharge when SOC is low.

6 Answers
WKirby avatar image
WKirby answered ·

Your thinking is good. It seems like you have thought about your design a lot. You are right that the Battery Protect is unidirectional.

Now, two of the BP's in your design are overkill. The ones for the MPPT and the Inverter are not really necessary. The MPPT has programmable Voltage limits and it can be switched off with remote contacts. It the same story with the Inverter, it has remote contacts to turn it off.

The BP going to the distribution board is well placed.

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Daniel D avatar image
Daniel D answered ·

Hi,


I will equip my future motorhome with Victron equipment for the third time.

Not wanting to risk damaging the LFP batteries, I would like to know if my diagram is correct?

What do you think ?


Best regards

Daniel


schema-656-a2.png (1.4 MiB)
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1. If you use a Victron BuckBoost you don't need a BatteryProtect there because the BuckBoost has an input for the charge disconnect signal from the BMS(green wire - must be programed).

2. Why you want to use separate inverter and charger instead of a MultiPlus?

Daniel D avatar image Daniel D Matthias Lange - DE ·

Hello M.Lange

I use a converter and a separate charger because I already own the converter, I just have to buy the charger.

Regarding the buck-boost, I prefer to start it with the D + motor because the vibration detection of the motor does not always work.

The detection is deceived by the water pump of the motorhome which causes the same vibrations as the engine.

Best regards

Daniel

D+(purple wire) and charge disconnect(green wire) are two different signals.
You can use both.
The BuckBoost will only work if both signals are high.

Daniel D avatar image Daniel D Matthias Lange - DE ·

Thank you M. Lange, so I will take the test.

With the TS config, I have to check "BMS Victron lithium protection" to activate input 2 (green wire) and "converter on/off with pin 1 (purple wire)" ?

Best regards

Daniel

ts-config.jpg (791.9 KiB)

Hi all,


Here I have updated my wiring diagram

I don't think I made a mistake, if you see one tell me.

Best regards,

Daniel

schema-656b-a2.jpg (825.1 KiB)

Wouldn't the new Orion DC-DC be a better option compared to old buck-boost? Much smaller form factor saving a lot of valuable space inside the van.

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The schematics looks good for me.

@spirou The Orion isn't really smaller.


h
w
d
Orion 30A
130
186
80
BuckBoost 50A
213
120
30

In volume the Orion has more then the double of the BuckBoost

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Longgun avatar image
Longgun answered ·

Hi

I am designing a system with x2 lifepo4 138ah 'powerwalls' which I bought without BMS. I am going to keep a close eye on the state of cell balance of the lifepo4's through a seperate Battery Capacity Meter plugged into the 4s lead.

My question is that Ive purchased the exact same set up as above. ie 300w panels, 100/20 smart solar mppt, multiplus 800/35 inverter charger, 712 battery meter, sterling B2B charger and and x1 battery protect.

Will x1 battery protect be ok and if so where is the best place to place it? Directly from the battery? Im a complete newby and if ogcampers schematic is good I would use it.

Many thanks for all your help!

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ejrossouw avatar image
ejrossouw answered ·

@ogcampers For me, one purpose of a good integrated BMS on Lifepo4 batteries is to manage protect, balance etc. itself from overcharge etc. I dropped the BMV 712 as my battery is the source of truth, it controls the SmartSolar Charger via a colour GX. In my opinion this setup may defeats the object of having an integrated BMS "smart battery" as it should already have this functionality integrated. PS - My Lifepo4 also has wifi and can even be remotely upgraded and managed remotely via a portal. It very much controls the whole system very efficiently and is used in self consumption mode.

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JohnC avatar image
JohnC answered ·

Looky here too OG. This Victron van is for showcasing, and may not have much room left for living in, but worth a look: https://community.victronenergy.com/articles/15035/victron-vw-van-electrics-install-schematic-drawing.html

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ogcampers avatar image
ogcampers answered ·

Thank you for your reaction. I will update my schematic :)

@WKirby Can you also tell me what parts I'll need to remotely switch off the Inverter or MPPT? Where will I find input (low/high voltage/temperature) to know when to activate the remote switch to the MPPT or Inverter.

Is it possible to let the BVM-712, provide an signal to the MPPT or Inverter?

Thank you in advance!

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Yes you can use the relay output on the BMV to control the inverter. All you need is a cable from relay ports to the others, but not sure you need to. I'm probably not qualified to give great design advice but I did something similar with my own Lithium battery. I use a Battery Protect to turn off the DC side of things when the voltage gets too low (controlled from my BMV 700) and the Inverter will turn itself off at a certain voltage. Then if there is still draw on the battery for some reason I have a Gigavac contactor to turn off the whole battery which is controlled by my BMS (zeva.com.au). It should in theory never turn off the battery, but if it does, it has to be fixed manually (i.e. can't charge the battery if it's turned off!). Here's what it looks like https://www.dropbox.com/s/mh1nay7oanmrdke/Artboard%201%402x.png?dl=0