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Battery Protect

Battery Protect and Capacitors

I plan to use a Smart Battery Protect on a circuit that will be used to charge batteries for an electric outboard. I am concerned about the warning in the manual about connecting inverters or anything with capacitors. The Epropulsion outboard uses detachable 48 volt batteries. A couple different chargers can be used that operate from 12 volt systems. Are these chargers similar to an inverter and do they contain capacitors?

fritzdfk asked

0 Answers

Can I use the H & L remote inputs of the Battery Protect at the same time?

Hi all,

Can I use the H & L remote inputs on a Battery Protect 65 at the same time from two different sources?

Ideally I'd like to use the High level input for a rocker switch to turn the BP65 on/off. & I'd like to use the Low level input for a BMV-712, SOC relay to switch the BP65 on/off.

I accept I could use both the switch & relay in series and switch either one of the H/L inputs. However being able to use both at the same time, in my case would reduce complexity & wiring.

Thanks for you input.

tg1 asked
tg1 commented ·

1 Answer

Battery Protect showing different voltage than charge controller

I have charge controller and inverter connected direct to battery, battery pos to pos bus terminal neg to neg bus terminal, pos bus terminal to battery protect, battery protect to pos loads, neg loads to negative bus terminal. My charge controller is reading 13.8 volts for the battery but the battery protect only 9, and so it cuts off power. What am I doing wrong? Thanks for any help

phatemi asked
phatemi commented ·

1 Answer

Small BMS in use with other charge controller

I am trying to set up a remote monitoring system for a single panel and battery system. I have a LiFePO4 smart battery for my system. I believe the small BMS is the best option for my situation. Before I purchase it I would like to know if it is compatible with other (non-victron) charge controllers? Other MPPTs suit my needs better does the small BMS need to be connected to an MPPT? Do I need a shut off, such as the battery protect, as well?

wior0474 asked
Paul B answered ·

1 Answer

How to protect your batteries against a failed Multiplus?

Many know that a battery protect cannot be connected between a Multiplus and the batteries. So if while unattended, the Multiplus throws a wobbly and either continuously charges or discharges the batteries, what can be used to disconnected it when the voltage exceeds some pre-defined limit? I know when it's working it will look after the batteries. My concern is when it fails. With a separate charger and inverter, a couple of battery disconnects could be used, but not with an inverter/charger.

I know many LiFePO4 batteries have a built in BMS which will disconnect them but I have a Batrium BMS which will ask the Multiplus (via the CAN bus and Color GX) to stop but cannot actually disconnect it.

I supposed I could use a big relay but I don't like the idea of having a permanently energised relay in the system.

I guess I'm looking for a 250A (I have the Multiplus 3KVA) common port battery disconnect.


Colin Mills asked
Colin Mills commented ·

1 Answer

Electric boat design review request and specific questions

Hello! We are building a 25' all-electric boat, with various Victron components and hoped to get some advice from the community. Questions are up top with details of the system farther down.


Battery Protection: We need to have battery under/over voltage protection on the 48V bank, but the largest 48V battery protect from Victron is 100A, which isn't high enough to have just one (We anticipate a potential burst load of say 8kW for 30 seconds or so, which is a 166A load). We could monitor each individual 48V battery with a separate BatteryProtect, but is this the best way to monitor and protect the batteries?

General System Design: Does anyone see a problem with what we have proposed in the diagram below? Any gotchas to watch out for? We are hoping the Cerbo GX and GX Touch 50 + iphone apps will provide monitoring and alarms for system operation.

12V system and battery: We need a 12V battery and require monitoring and protection for it, ideally victron branded and something we can monitor using with the GerboGX alongside the rest of the system. It doesn't appear that the 12V batteries from Victron natively connect to the Cerbo GX, will this require a BMV712 or smartshunt to be monitored? And if so, which is recommended?

Solar System: We will probably have two different sizes of solar panels on the roof of the boat, potentially with different nominal voltages, would that require two different solar charge controllers? Thoughts on flexible vs rigid panels, and the Victron charge controllers that would be best? We haven't purchased the panels yet so needed details are missing but any general advice is appreciated.




Gavia Electrical System Design


Description: Gavia is a 25’ all-electric solar motor boat under development.

48V DC System: The motor is a brushed 7.5 kW DC 48V Thoosa Electric Motor. We hope the nominal draw will be around 1-2 kW while under way, but short bursts (1 minute) of 7.5kW are expected (we have not tested the boat in the water yet). Energy will be provided by a 48V lithium-iron battery bank. Solar cells on the roof will be the primary recharge method, hopefully 1kWp or greater, with AC shore power and backup 1kW generator for AC charging on-the-go. A hybrid inverter/charger should be a convenient way to pack lots of functionality into one box, and AC input/output should be 120V (we are in the USA).

12V DC System: The 12V DC system will be used to run low-wattage house electronics (navigation, radio, windless, house lighting, etc), and 12V bow thruster whose max draw is 1500W. This larger 12V draw necessitates a 12V energy bank (vs relying on DC-DC converter), so a 12V 100+A lithium battery will be used and it should recharge from the main 48V system.

120V AC: 120V AC will be used for a minimum number of appliances onboard, the largest of which is the induction cooktop with a 1800W maximum draw. This will be provided by the hybrid inverter/charger.

Note that we do not anticipate running the high power loads at the same time. For example, we won’t run the induction cooktop while the electric motor is running.

Here are some system components:

  • Inverter/Charger: "PMP482305100 MultiPlus-II 48/3000/35-50 120V"
  • 48V Bank: SimpliFi PHI 3.8-M ("PHI3.8 48V 60 VTE BRK") wired in parallel (x4)
  • Onboard component monitoring (interior): "Victron Energy BPP900455050 GX Touch 50" with "Victron Energy BPP900450100 Cerbo GX". Onboard component monitoring (exterior helm station): ipad similar device running victron app, with weatherproof case
  • Battery Capacity Shunt: "Victron Energy SHU050150050 SmartShunt 500A/50mV"
  • Battery Protect: Undervoltage/overvoltage protection: The batteries have a BMS, but we need an additional protection for the battery bank as a whole or the individual batteries.
  • 12V DC Charger: We will use an AC battery charger to charge the 12V bank. We cannot use a DC-DC charger for this because the Victron DC charger is not isolated; the motor requires no other DC systems on the negative side of the 48V system
  • 12V House Loads Battery: something with 1kWh of energy and built-in BMS, and some way to monitor the voltage.

ev-gavia asked
shaneyake commented ·

3 Answers

why can I not use a smart battery protect between battery and inverter?

Hi all,

Just bought a battery protect (the larger smart one/forgot the details, sorry).

Thought I could hook it up between battery and loads and have it turn off current in case of battery-low-voltage. As a safety measure thing.

Then I`read:

you cannot use this device between your batteries and an inverter (...)

Is this for real?

Of course I have an inverter! Don't we all?

How am I going to battery (lowvoltage) protect my system?

My set-up is 4x 160W panels, MPPT 100/20, 12V system

thanks for any advice,


westen asked
shaneyake commented ·

3 Answers

Smart Batterie Protect auch zusätzlich als Batterieschalter nutzen?

Moin Zusammen,

ich stelle mir gerade die Frage, ob es möglich ist die alt bekannten Batterieschalter durch zum Beispiel einem Smart Batterie Protect zu ersetzen. Hier kann ich an den Pins Remote per Schalter auch den Out Ausgang abschalten, so als wenn ich per Batterieschalter ausschalte.

Ich weiß, das die Hauptfunktion eine andere ist, nämlich die Batterie vor Unter- oder Überspannung zu schützen.

So hätte ich aber beides in einem Gerät.

Schaltung wäre:

Batterie Pluspol - Hauptsicherung - Smart Batterie Protect

Danke für eine Antwort!

Gruß Norman

Norman Kühn asked
Norman Kühn answered ·

2 Answers

Contradiction in 220A battery protect manual ?

Hi folks.

Trying to avoid an expensive mistake

before finalising my wiring!

having read the battery protect manual i fully get that Vout should not be a higher voltage than Vin. Makes complete sense.

But on the last section of the manual,

It shows 2 battery protects in series where:

The input of battery protect 2 is connected to a charger (MPPT stated)

The output of battery protect 2 is connected to the input of battery connect 1 which is commoned to

Battery bank positive.

The output of battery protect 1 is then connected to the load.

And in one sense that works in my mind - insofar as no input to battery connect 2 Shuts down battery connect 2s output.... the sun goes down....there is no volts on the input to battery connect 2 therefore, at that point in time the output of battery connect 2 is at battery voltage...BUT the input of Battery connect 2 is at zero V (no charge coming in) so at that point you have an "approved" configuration where it seems there is potential to cook battery connect 2 !!??

So ....other than fitting a 60-100A Rated schottky diode on the output of Battery connect 2 so that the battery can never reverse shunt battery connect 2 , how do you stop Batt connect 2 being fried when no charge current is present on its input ?

To my mind the manuals statement and the last drawing are in contravention - which is right please?



bigbloke asked

0 Answers

Battery Protect 100 remote on off and external on/off both connected possible?

I have a BP100 in a Lithium system with a VE Bus BMS. Can I use the remote on/off switch (as in the standard diagram) in combination with option C (Li-ION), so the external on/off signal also connected? I want to have the capability to turn off DC loads connected to the Battery Protect, independent from the BMS

mberg asked
Matthias Lange - DE answered ·

1 Answer

Cause of total system shutdown???
Looking for answers on what could be the issue with our Victron system...(3x 200Ah "Smart" lithium batts with Victron BMS, BatteryProtect, BMV and Color GX monitors, Quattro inverter/charger, MPPT controllers, etc.....all Victron).
A couple of weeks ago, we were hit by a heavy squall, with 35-40kn true wind on the nose, in large confused seas. The autopilot, an NKE driving an L&S hydraulic ram was struggling with the excessive weather helm. Just as we were preparing to put in a 3rd reef, the entire boat "went dark" without warning. No autopilot, instruments, gps, radio comms, or lights.....all 12v circuits on the boat were dead! And just as we really wanted the autopilot to keep driving as we tucked in another reef. The boat was on her ear, (we later found seaweed draped over the leeward lifeline!!!). As we struggled to regain control, all of a sudden the boat "lit up".....all 12 volt circuits started up again!!! YEE HAH!!! we did a quick happy dance!!! But our happiness was short lived, as the cycle of off/on happened 3 more times over the next hour or so. Visibility was very poor, as the rain got heavier. We started the motor (it has a dedicated starter battery) and dropped the mainsail for the last bit of the overflows. At last we rounded the Mull of Galloway and gladly headed north. Conditions have been comparitively mild since then, and the problem has not recurred.
So what happened to our electrical system? After all, having the boat shut down like that at the wrong time could be disastrous. Had this occurred at night, in shipping lanes, ships tracking us on AIS or visually by our lights would not have known we were out there. And similarly, we would have been "blind" without radar or AIS to spot ships. While we still have no definitive answer, at this point all signs point to the Battery Management System (BMS) of the lithium battery installation. It's the only thing which would shut off all of the loads like this. The job of the BMS is obviously to protect the batteries, and will shut down all loads on the system if it senses low overall system battery voltage, overheating of the batteries, or cell imbalance between individual cells in the batteries.
According to the installing electrician/dealer, he feels that the system was "operating normally"!!! That given the struggle of the autopilot in these wind/sea conditions, it is possible that the demands on the battery bank MAY have caused a cell imbalance which caused the BMS to shutdown, even though the overall battery voltage was fine (we'd been charging while hooked to shore power for 3 days so had been 100% only 2 hours earlier).
I am having a hard time thinking of this as "normal operation". Normal operation of critical systems cannot simply shut down without warning, or the system is not suited for purpose!!!!! And also that a cell imbalance could have been brought on by excessive load on the batts. (the autopilot only requires a 30 amp 12v, that's just 360 watts, .05c, far less than the load imposed by an induction hob or microwave which we often use for longer periods through the inverter without effect.). While of course I was a bit too busy to check the individual cell voltages with VictronConnect during the shut down, whenever I check the voltages at other times, the 12 cells are all within .01 volt of one another. Any ideas of what could have caused this shut down (it has not happened since)??? And what could prevent it in the future? I am thinking of installing a battery switch in parallel with the terminals of the BatteryProtect relay, normally kept open, in case of another emergency shutdown, though I have been advised that it's use could void the warranty! Any suggestions are welcome!

svbravo asked
shaneyake commented ·

3 Answers

Exlplain remote on off switch for battery protect?

I thought I understood how to use the battery protect remote switch terminals to wire to my inverter on off switch thinking the battery protect would shut off the inverter upon low voltage or when I shut it off in the app. The directions seem simple enough, but it doesn't work. Iv tried every possible configuration. I understand the inverter terminal should never be connected through the battery protect, yet many people tell me they have been doing just that long term with no issues.

Why wouldn't the battery protect be designed to work with an inverter or even an inverter on off remote switch? What am I missing?

Why does this device seem useless and overpriced?

The app has no audible notification of low voltage. My inverter will drain my batteries with no help from the battery protect. Really? Why? Is my only option an annoying alarm that will wake me up in the middle of the night and force me to manually turn off my inverter? Or is there another way? Is a relay my only solution? I want the battery protect to do what it should, turn off my inverter when my batteries reach low voltage. Is that too much to ask from the battery protect that cost me $80.

I have no dc loads to use with it other than my inverter.

Thank you in advance. I sincerely hope I do not have to return the item for a refund to use a much cheaper device that will do the job.

aceclement asked
wkirby commented ·

3 Answers

BatteryProtect display meaning

A BatteryProtect 12/24V-100A is used as load shedding controlled by a VE.Bus BMS connected to a LiFePO4 Battery 12,8V/100Ah Smart. After a full charge of the battery we sailed off and after about 5Ah consumption (navigation instriuments + rudder control) the BatteryProtect has cut off showing a moving "C" on its 7 segment LED display.

What does this moving "C" mean?

Also, after some hours' rest (about 7 hours, while the system was switched off) is has resumed without intervention. Why?

Unfortunately the sailing conditions were harsh enough not to be able to check the fault at once, and when got back to the marina, the system was OK.

Any clue is welcome! Thank you in advance.

a-v asked
mcdoo answered ·

1 Answer

BatteryProtect needed with smart LifePO4 battery?

Is the BatteryProtect needed/useful with the smart LifePO4 battery?

Does the battery itself stop sending current when its voltage is too low?

The battery itself has an "Allowed-To-Discharge cell voltage" setting, the manual says "As soon as one of the cells reaches this voltage, the BMS will disable all loads by sending a signal to the load or to the load disconnection device.".

I don't understand if the battery is smart enough to stop sending power to devices once that voltage is reached, or it (and the VE.Bus BMS) needs a "load disconnection device" that acts like a switch between the battery and the load.

A standard load wouldn't care about a stop signal, unless that signal was a complete lack of current.

I often see the BatteryProtect in schematics but it seems the battery with the (VE.BUS BMS which is directly recommended) may already be equipped to protect against under/over voltage.

trougnouf asked
drlbradley edited ·

3 Answers

Increase Smart Battery Protect Overvoltage

Is it possible to increase the smart battery protect overvoltage from 32 to 33V?

I’m using Nissan Leaf batteries and so my 24V actual operational voltage on the high end is 32.88V and I’d love to be able to continue charging from the MPPT through my smart battery protect all the way to 32.88V instead of having to set it to 31.9V.

dragon-wagon asked
nebulight answered ·

3 Answers

Yacht installation Lithium

I'm upgrading to Victron Lithium on my yacht, 3 x 100AH type.

I have the MPPT100/30, BMV-712 already installed, and recently puchased the CL 12/100, and the VE non inverting cable to go between the MPPT and CL12/100.

I also purchased the 220amp Smart Battery Protect, as i'm running a 2000w inverter (not Victron).

I managed to "blend" a couple of schematics from Victron, and just wanted to check that it all looks good before i install the system.

Other relevant info is the boat has a 100A alternator and 600W of solar panels, (2 x 200W fixed and 2 x 100W flexible that i bring out in winter)

Can i get some feedback on this schematic? Most importantly have i messed something!!


diamach asked
diamach answered ·

3 Answers

Short Circuit Load Output

Hi, We have made up a 12v 600Ah LiFePo4 battery using a 100/20 Victron Controller. we had 2 x 200W solar panels ready to power a road sign, so all they had to do is connect the PV and the load and they were done, however when our installers installed it to a load, they told us there was no power on the load available, so they used out direct power feed we had built in as a redundancy. We went down a few hours later to check what they had done and there was clearly power available at the load. Is it possible they short circuited it during install on the load or PV and its simply reset itself? We cant check the BT as its installed in a way that is not possible. Any thoughts would be helpful.

scott72 asked
wkirby answered ·

1 Answer

Can I use a Victron Battery Protect to Cut solar input on my motorhome when the engine is running?

The reason for my question above is because I have a 50amp DC-DC charger however with the engine running and solar connected it will only charge at 25amps. Im therefore looking for a way of cutting the solar power input when the vehicle engine is running. This way I will get the full 50amps of charge.

judder asked
judder answered ·

2 Answers

Smart Battery Protect with SmartShunt


From reading the manuals the SmartShunt compared to the BMV devices is lacking the pins to set an output alarm or relay.

Which means that I cannot use the SmartShunt together with the Battery Protect to disconnect my DC loads based on the SOC of the battery.

However as both the SmartShunt and the Smart Battery Protect have bluetooth and I have seen in the app that there are networking features, can the SmartShunt talk to the Smart Battery Protect wirelessly and tell the Smart Battery Protect to disconnect my DC loads when let's say my lead battery reaches 50% SOC?

Thank you very much,


alexandruy2k asked
alexandruy2k answered ·

2 Answers

BP-100 Programming Question

When I connect the BP-100 Programming pin to ground the device sequences as follows:

E, h, 5, 9, L, 8, 6, 0, 1, 2, E, h ...

I would like to program the device to use from the table in the manual "3", however I never see option 3, and given the numerals I see I wonder am I seeing an error condition?

Any suggestions?

Thanks, Jeff

n85ae asked

0 Answers

Smart Battery Protect high voltage disconnect


The Smart Battery Protect has a fixed high voltage at which disconnect happens. Would it be possible to make this adjustable via the app?

aoh asked

0 Answers

How to connect a Victron battery protect between power inverter and battery

I currently have a small, off grid solar system - 100amp deep cycle sealed lead acid battery, 100 watt foldable solar panel, 20A charge controller and a 12V/750watt power inverter.

The power inverter is currently connected directly to the battery but I am concerned about over discharge if there are multiple consecutive cloudy days.

I purchased a 100A Victron battery protect. I am confused as to how to connect it to the battery and power inverter in order for it to prevent the battery from being over discharged.

  1. Does the power inverter connect to the battery protect and then the battery connect to the battery?
  2. Which connection do I use on the battery connect - IN or OUT?
  3. Where does the battery connect negative/black wire connect?

rwkoehler asked
aceclement commented ·

2 Answers

Battery protect 220A, voltage drop

Have a BP 220 unit. IN-pin connetcted to plus on Li bat with fuse inbetween. Also connected to IN-pin there is a multiplus and a smart solar connected.

When I add load through the BP I got voltage drop when turning on smal consumers from 13.4 to 12.9v (lamps). When using bowthruster och windlash the system shuts down totaly.

If I remvoe the BP everything works fine, what is the problem?

I have bought a second BP and I got the same behaviour with that one.

Best regards


kim-hilding asked
kim-hilding commented ·

2 Answers

Battery Discharge Protection - Inverter

I have a mobile (Caravan) system that is Lithium based but I DO NOT have Victron Lithium batteries. My batteries also do not have an accessible BMS. They are a Renogy 170 AH lithium batteries.

My system is charged via a Victron 100/50 Smart Solar MPPT and a Victron 30 amp AC charger. I also have fitted a BMV712, smart battery sense and a 65 amp Smart Battery Protect.

I am about to install a NON Victron Inverter 2800/5600 watts to see how much I can do via 240v instead of gas. Induction cooking etc.

my question is about how I best protect my batteries from over discharge whilst using the inverter.

I have read that you should not use a Smart Battery Protect on an inverter. Is this correct?

if you can then the 220 amp model it may be a bit small (2640 watts).

Can I use the BMV712 to activate a relay to disconnect the inverter?

Are there any other alternatives?


strop asked
aceclement answered ·

3 Answers

Battery Protect & cerbo

I have bought 5 Battery Protect and did not choose the smart Option with bluetooth. Can i connect the Battery Protect to a Cerbo GX and control the Battery Protect with it then ? thanks

harrystuck asked
wkirby answered ·

2 Answers

Smart Battery Protect settings for Superpack 100ah

I have a 12/24v 100A smart battery protect and a 100ah SuperPack 100ah lifepo4 battery. I was wondering if anyone can tell me what the settings should be for the shutdown and restart voltages should be. The spec sheet says 'End of discharge voltage' which is 10v but is this the correct value and if so what would be best for the restart voltage?

dwiea asked
shreeyash answered ·

1 Answer

2x Victron SmartSolar MPPT 100/20 and Battery Protect

Hi there!

I am planning a setup with 2x MPPT Smart Solar 100/20 with 3x100Wp Modules each.

I also want to use a Battery Protect 65A for my Loads and also a Battery Protect for the already existing Battery Booster from another company. At the beginning I also wanted to run the Smart Solar through a battery protect.

But as far as I understood the Smart Solar 100/20 already has a kind of built-in Battery Protect. So there is no need to plug the BAT+ through an extra battery protect, right?

In the Manual there is a schematic that shows that the plus of „DC Loads“ is connected to one of the Battery Protect.
(I guess it can also be connected to both of them?!)

But what actually is this connection doing?

best regards and protect your energy!

protectyourenergy asked
raphael answered ·

1 Answer

BatteryProtect ok for generator starter?

Hi, I plan to use a Battery Protect to add LVD to the loads in a motorhome as part of a lithium conversion.

Due to layout it is easier to use a BP220 to protect the entire DC load bus but that also includes the generator starter feed - which is 100A.

The question is I do see that the BP doesn't like capacitive loads like an inverter and understand that. But what about inductive loads like a generator starter motor?

The other option would be rewire so the generator starter was not off the DC bus but sourced directly back to house batteries and use a contactor as the LVD. The issue here is a lot more wiring to run making the retrofit more complex.

jw1971 asked
jw1971 answered ·

1 Answer

LiFEPO4 and windgenerator regulator problematic?

I am evaluating a change from 4x100Ah AGM to min. 200Ah LiFEPO4 on my cruising sailing yacht in the near future (I have in mind to keep the existing separate 75Ah AGM starter battery) and have some uncertainty withmy existing windgenerator (and also with my sterling A2B).

As far as I am reading so far one or more BMS controlled battery protection relays like the BP220 battery protect or a cyrix li charge (what is the difference?) shall be installed between the chargers and the LiFEPO4 battery bank to protect the batteries from overloading and low voltage etc.

I have the following loading sources already included in my setup:
- 120A inverter-charger Victron MultiPlus 12/3000/120/50, reduced to 50% in settings
- 50A solar charger (Victron MPPT 50/100, solar panels connected: 600Wp)
- 60A wind/solar charger (Silentwind hybrid MPPT charger, installed: wind generator + 310Wp solar panels connected), LiFePO4 charge possible
- 115A alternator (Mitsubishi A003TR0091ZT 115A) connected to Sterling A2B Pro Alt C 130A (LiFePO4 charge possible)

I assume a battery protect between the MultiPlus and the battery would not be necessary, because the multi directly can be connected to the BMS via and therefore shut down by BMS in case.

What I saw in the silentwind regulator manual is that the hybrid regulator can be destroyed in case it´s disconnected from the battery when still connected to the wind generator and/or solar. So do I have to decide what "shall be destroyed"? So if I decide for a battery protector relay I decide to protect the batteries, but would risk the silentwind MPPT charger?

Quite the same uncertainty I have with my sterling A2B.

Beside the above mentioned I have the following components already installed in my setup:
- BMV712 battery monitor
- VenusOS on Raspi4 with Node Red (Multiplus, BMV712 and MPPT 50/100 are connected)
- VE.bus smart dongle
- battery sense

Would be great if you could give me some hints, thank in advance!

Dosheimer asked
Dosheimer answered ·

4 Answers

Can the Battery Protect be used as a HVC

Can the smart battery protect be used as a simple HVC on the charge side of a set of LiFePO4 batteries without any kind of external relay or communication from a BVM?

Intended use would be to set a cut off voltage, and rely on the SBP to be the first line of defence to disconnect charging sources if they ever rose above whatever voltage I'd set on the SBP?

I'm presuming it has bluetooth so I can set the required disconnect voltage?

mikedefieslife asked
Brian Johnson commented ·

4 Answers

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