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Victron SuperPack 12,8v 100Ah and a 140A alternator

Hi everyone,

Just bought a Victron SuperPack 12,8v 100Ah battery, this battery has the BMS integrated this is the reason why I chose it.

This battery will be installed in my camper van as a leisure battery, but a big question question come to mind, will my 140A alternator sustain the charging load.

From the battery's technical datasheet, it only pulls up to 50Amps when charging, but is this really the case ?

Since this battery has a BMS of its own, does it control the current pulled when charging ?

Can this limited charging current be set in the battery's BMS via the mobile app?

Will I need a DC to DC charger in-between the alternator and the battery ?

By the way, the alternator is a Valeo 439753 which is regulated and I currently have an 80Ah battery as my main battery and also a split charger relay.

Thank you in advance for you response


Philouteke asked
Philouteke commented ·

2 Answers

Alternator Charge Current Estimate at 13.8 Volts


I am planning the upgrades to lithium for my motor home. And I'm trying to estimame and budget for whether I NEED a battery to battery charger or if I can get away with just alternator charing through the BMS.

Looking to start with:

1 x Victron Lithium 12V - 100Ah Smart and CL BMS 12/100

I know i can limit the current using fuses on this BMS to protect my alternator.

Reading the litrature for the battery it recomends charge voltage of 14V to 15V. 14.2 being needed for cell ballance.

I'm only getting 13.8 volts from my alternator and I'm worried I wont be able to charge (or top up ) by lithium batterys without adding a B2B which can boost the voltage.

My question to anyone who can help me is:
My alternator only puts out 13.8 volts.

Will I still be able to charge the lithium pack at a sensible rate with a marginal voltage difference and below the recomended charge 14.0 charge suggetion?

I'd like to be able to top off the batteries at 50Amps from the alternator - is this feasable without boosting the voltage using a b2b?

Not knowing the internal resistance of the lithium pack I can't calculate the sort of charge current I could expect.

Does anyone have some first hand guidance of charging from alternators of lower voltage ?

thanks for the help



TonyJobson asked

0 Answers

How does Cyrix-Li-ct work?

I just replaced my original battery combiner with the Victron Cyrix-Li-ct. I tied the small read lead to both my dashboard wire (AUX START) and to AM Solar's AMS Lithium Control Module v4.2 to the ALT + and - connectors.

Can someone explain to me how this relay is supposed to work? I have 3 typical scenerios: (1) vehicle running (class A motorcoach) with no solar, (2) shore power and (3) dry camping with plenty of solar.

Is this a "one-way" solenoid? Are both lithium batteris and chassis batteries affected in the above scenerios?

I've included the data sheet from Victron for your refereance.


Edgargw22 asked
abogaard commented ·

3 Answers

A Victron - Mastervolt Hybrid System?

Hello everyone.

Has anyone built a Victron - Mastervolt hybrid system? Why not select the best elements from both if building a solar/lithium battery system for a boat from scratch? Victron’s open-systems approach enables this.

I’m designing a lithium battery system for a sailing yacht, currently under construction. Basic parameters are: ~1200Ah of lithium batteries; 1200W of solar panels; combined inverter/charger with shore power connection; no generator but twin alternators; worldwide sailing program including Arctic/Antarctic environments.

I’ve been looking closely at Victron and Mastervolt systems, along with batteries from other suppliers. I’ve been struggling to reconcile a few concerns.

While I’m happy with most elements of a Victron system, weaknesses are:

- integration and control of alternators. While Victron offers modules that can shield lithium batteries and alternators from each others’ damaging tendencies, it doesn’t provide a fully integrated method for controlling alternators, so that they can deliver ideal battery charging.

- the low IP22 rating of the batteries. IP22 might stop small rocks and drips of water from getting into the batteries, however, these will be installed in the bilge area of a rocking and rolling sailing yacht. Hmmm. :-/

- a Victron lithium battery warranty will be voided by any charging below 5℃. The yacht will be used in Arctic and Antarctic locations, where water temperatures down to 1 or 2℃ are higher than air temperatures. To take advantage of this the hull is uninsulated below the waterline. Keeping the batteries warm will not always be convenient, but catching what sunlight is available will always be important.

Some problems with Mastervolt's offerings are:

- solar charge controllers. Mastervolt’s range is small and performance of the best candidate is insufficient.

- system programming and monitoring. Mastervolt’s software for programming system elements is effective but is far less user friendly than Victron’s. Mastervolt’s monitoring and control displays are less convenient. Victron’s options for Bluetooth interfacing, with Apple iOS and OS X apps and software is a big plus. The ease of interpreting energy flows via Victron’s GX devices can’t be matched by Mastervolt’s presentation of discrete numbers.

I’m thinking that an ideal hybrid system for my yacht, using the best of both makers, will be to ask the builder's electrical engineer to install:

From Victron:
- Cerbo GX and GX Touch 50, for system status display including tanks and pumps and to control charging via DVCC
- MultiPlus 12/3000/120-50
- Smart Solar MPPT 100/50 (x3)
- SmartShunt 1000
- Phoenix IP43 24/25 charger, for bowthruster battery charging

From Mastervolt:
- 3 x 12/5500 MLI lithium batteries (400Ah each). IP65 protection rating! No warranty voiding by charging below 5℃. With 3 x BlueSeas ML RBS safety switches - to cut loads and charging in the one unit, which also has a manual isolation switch. Brilliant! And a Blue Seas ML ACR battery combiner - to charge both house and engine-start batteries from alternators
- 2 x AlphaPro III alternator regulators - programmable for Bulk, Absorption and Float charging. Better and easier than Balmar's offerings I think.
- MasterShunt - to send battery voltage and temperature data to the alternator regulators (might not need this if the regulators can get this data directly from the Mastervolt batteries via Masterbus)
- Masterbus to USB adapter - to enable programming via MasterAdjust software and effing Windows.

This thread advises that using two shunts will work. This will be important, so please speak up if you can see a problem.

DVCC should work. Victron's GX devices appear to be battery agnostic. I don't plan to connect the Mastervolt batteries to the Cerbo's BMSbus port, but doing so might be a future project.

Thoughts? Comments? Suggestions?

Thank you.

Edit on 28 Apr 2020. A thought is that I can get the great performance of the Mastervolt AlphaPro III alternator regulators without necessarily needing the Mastervolt batteries. All I need is the Mastervolt shunt, which will communicate with the regulators and keep the alternators safe, performing well and charging the batteries well. This means I can use Victron lithium batteries if desired. That's handy.

Valden asked
Valden edited ·

2 Answers

Correct Installation of smartshunt, solar and alternator


i nearly finished my electrical system in my van but still have a question regarding the correct installation of the alternator in the system. I have the Victron Smartshunt 500A.

My question is:

Do i connect the minus-output of the alternator via the carbody directly to my battery (see my diagram: 2) or to the smartshunt (1 in the diagram)?

Is it bad, if my battery has the only connection to the ground/body via the smartshunt?



Lokus asked
Lokus answered ·

3 Answers

Cerbo GX, DVCC and combined charging from Multi, MPPTs and alternator. How measured?

Hello all.

I have some curly questions on using a Cerbo GX and Distributed Voltage and Current Control (DVCC) to manage the system described below.

The yacht installation I’m preparing will have four Victron 12.8V 300Ah Smart LiFePO4 batteries, arranged in parallel. Their overall voltage will be sensed by a SmartShunt, connected to the Cerbo by VE.Direct. The batteries’ 3 Pole Balance Temperature & Voltage (BTV) cables will be daisy-chained to a Smart BMS CL 12-100. This BMS will control a Smart Battery-Protect 220 via its Load Disconnect terminal. The BMS will also control a Cyrix-Li-Charge 120 via its Charge Disconnect terminal. Three Smart MPPT 100/50 solar charge controllers will send current from 1200W of solar panels to the batteries through the Cyrix. The MPPTs will connect to the Cerbo by VE.Direct-to-USB adapters, into a USB hub and then to one of the Cerbo’s USB ports. Another job the BMS will do is regulate battery charging from a 115A alternator.

The system will include a MultiPlus 12/3000/120-50 inverter/charger, connected to the Cerbo by VE.Bus. Current from the MultiPlus will not be routed through either the Smart Battery Protect 220 or the Cyrix-Li-Charge 120, to avoid damaging those with flow in both directions.

I’ve read Victron’s explanations of DVCC, along with relevant discussions here in the Community. I’m satisfied it will work. What I think will happen (and not happen) is:

- the Cerbo will take the battery voltage sensed by the shunt and assess this in terms of what it was told the batteries are, during setup;

- it will look up its program library of how these batteries like to be treated and will instruct the MPPTs and the MultiPlus how they should serve up amps for charging, or draw on them for inverting;

- when the Cerbo assesses that the battery voltage reported by the shunt is getting low, it will tell the MultiPlus to stop inverting;

- the Cerbo will not be able to stop the DC loads from drawing upon the batteries, as it has no data connection to the BMS or the battery-protect. These two will use their load-disconnect linkage to cut the loads when one of the batteries says ‘Stop!’;

- if something goes wrong and the Cerbo doesn’t succeed in stopping the MPPTs from charging, the BMS will step in when the batteries ask it to and stop the charging via its charge-disconnect link to the Cyrix;

- however, if something goes wrong and the Cerbo doesn’t succeed in stopping the MultiPlus from charging, there’s nothing in the system or the setup to cut it off. I assume that the MultiPlus will not stop itself from charging, given it’s been told to be dumb and work under DVCC rules. Perhaps I could add a Cerbo controlled relay as a back-up, to switch off the MultiPlus if it goes feral?

Please set me straight if any of the above is off-beam.


Some aspects I’m less clear on are:

- will the shunt report the overall charging current from the MPPTs, the MultiPlus and the alternator, such that the Cerbo might instruct the MultiPlus and the MPPTs to ease-off or stop?

- if the batteries are full, does the BMS have the ability to throttle the current from the alternator? Checking … . Yes, it does.

- and last but not least …

… the Cerbo GX has a second pair of CAN-bus ports, called BMS.Can. Little is written about these, other than how they can be used to hook up other-brand CAN-bus BMS equipped batteries or BMSs. So how good would it be to have Victron lithium batteries that can talk directly to a Cerbo over CAN-bus? :-D Has Victron said these are on the way, or ruled them out for some reason?

Valden asked
Valden edited ·

3 Answers

Alternator w/ WS500 and Victron Venus or Cerbo

I love the Victron Venus system and would love to upgrade to the Cerbo (if i can every get my hands on one). I'm currently in the process of upgrading our alternator on our yacht. For this we will use a WS500 regulator which has the ability to get data from the victron BMV shunt in order to control voltage and Amperage coming from the alternator.

My question: is there anyway to see only alternator output through a venus or cerbo device? I know that the WS500 has a CAN bus but i would be unsure how these two devices would communicate or if there would be any way to display that information. It would be very helpful to understand what all the charging systems are doing (solar, wind, alternators, etc) on a single screen.

I do believe the answer is, no, there is no way to do this but i figure i would ask before i close the door to the idea.

polarseal asked
Paul B answered ·

1 Answer

With the Smart BMS CL 12V 100A, is a VE.Bus BMS still needed?

Hello everyone.

For the lithium battery system on my yacht I've been planning to use a VE.Bus BMS to manage and protect the batteries. Now that I've been made aware of the Smart BMS CL 12V 100A, which I will use to protect the diesel engine's alternator from having the life sucked out of it by four big lithium batteries, I'm wondering if the VE.Bus BMS is still needed?

The Smart BMS CL 12V 100A has the same three control outputs as the VE.Bus BMS; load-disconnect, charge-disconnect and pre-alarm. So it can handle those jobs. But it doesn't have the VE.Bus BMS' mains detect cable connector. Perhaps this function isn't needed?

Does the MultiPlus inverter/charger need the mains detection connection?

Does the Cerbo GX need the mains detection connection, via the MultiPlus?

It's looking like I can adopt the new Smart BMS CL 12V 100A, drop the VE.Bus BMS and also drop the mains detector.


This Smart BMS CL 12V 100A could well be the best thing since sliced bread. :-)

Valden asked
Valden commented ·

1 Answer

Choosing a DC-DC charger - truck camper with LiFePO4

I'm looking into buying a DC-DC charger for my truck camper, but I'm unsure which one. Here are the details of my setup:

- Truck: 6.5L diesel engine with 100A alternator, 2 AGM starter batteries (12V parallel)

- Camper: 200Ah LiFePO4 batteries, 8AWG wiring on the DC input

- Alternator outputs around 13.5V, LiFePO4 batteries need around 14.5V (i.e. stepping up the voltage is a must)

Based on those details, it seems like the Orion-Tr Smart 12/12-30 would fit the bill, but I'm concerned about the following:

1. Does the Orion-Tr Smart require a remote connection to operate, or can it switch on and off based on input voltage reading alone? I'm going to install the charger on the camper, so I won't have access to the ignition switch, so the only way to determine if the motor is running is by measuring the input voltage - can the Orion-Tr Smart do that?

2. Is 30A reasonable for 8AWG wiring with a 100A alternator? It seems to me like it would be OK, but the charger will be far from the alternator (probably around 5-10m of wire).

3. Is the Orion-Tr Smart the most cost-effective solution for my use case? Another option is the Orion-Tr (without the smart part), but I'm not sure if it can handle LiFePO4 charging.

Thanks in advance to anyone who can help me with this!

theodk asked
Justin Cook - Bay Marine Supply USA commented ·

1 Answer

when batteries being charged from alternator the volts jump up to 14.1 but the battery % continues to decrease

I have a multi plus 12/3000,connected to a BMV battery monitor and a CCGX colour screen - when on shore line the batteries charge normally and the CCGX shows 100% charge batteries full. However when I disconnect the shoreline and run the engine over a four hour period the batteries are going down as well as the percentage - have had the alternator checked and the cables from the batteries to the shunt have been tested with a clamp meter for the amps and voltage but the equipment is not detecting any amps volts etc - any ideas?

MBase asked
Guy Stewart (Victron Community Manager) commented ·

0 Answers

Alternator charging of gel battery bank: how to prevent overcharging?

My boat has a bank of 8 house batteries (110-amp Victron Deep Cycle Gels), wired in series for 24 V, i.e. 4 sets of 2 batteries each.

I have a 24V 60W alternator on the main engine, which puts out about 28.5V 30A constant at cruising speed.

Question: can I use the alternator to charge my house battery bank when cruising, without danger of damaging the batteries? I'll be cruising for a month, as much as 8 hours a day.

Thanks in advance,


dasnider asked
dasnider commented ·

2 Answers

Addition of Orion Smart DC to DC Charging

Here is my configuration thus far: LiFePO4 House bank, AGM (or SLA) Start Battery. Alternator is 120A non-smart (one option considered is the Balmar retrofit kit but cost is more than the Orion Smart DC Charger) The House was an AGM bank before and both batteries were connected through an electronic battery isolator for charging (diesel engine alternator and shore powered charger and Solar MPPT).

I've read that it may be advisable to keep the Lead-acid start battery from a starting CCA capability AS WELL as a safety consideration -- should the BMS ever disconnect the LiFePO4 bank (over or undervoltage) and say the engine is running, I am concerned the alternator could burn out or excess voltage be pushed through my DC system, damaging electronics.

Since I will have to disconnect one bank from the shore power charger (it can only be set to Lithium or Lead Acid charge profiles) I was wondering if the Orion Smart Charger would help to provide Alternator charging to the House bank through the Start Bank.

The rationale for leaving the Lead Acid connected to the alternator is that 1. Serve as protection from overcharging as it is cheap(er) to replace, 2. the chemistry prefers to be at a higher SOC and can sustain higher/longer levels of charge should we motor for longer periods.

Thoughts? I've seen others who charge from house to start bank. Or is there a product that provides 2 bank DC to DC Charging (using different charge profiles)?

thebarold asked
thebarold commented ·

1 Answer

Charging my LifePo4 with an alternator


I am designing my setup but the only thing that is not clear to me is how to safely have my batteries charge through my alternator.

The battery will be a LiFePo4 battery, 12V 600Ah.
Inverter/charger Victron Phoenix 12/2500/120
700W of Solar through SmartSolar 100/50

I am still deciding on the BMS. My van is a 2006 Renault Master, so I'm pretty sure it's not one of the newer "smart alternators".

From what I can find online it looks like there might be a way to use either a BMS or a VE.Bus BMS to do this? I would like the alternator to be connected to my starter battery at all times, and connect a system to that that
A) Doesn't destroy my alternator
B) Doesn't drain my starter
C) Shuts off charging when battery is full

Has anyone already made a setup like this?

Thank you!!!

shivadas asked
shivadas commented ·

3 Answers

How to prevent alternator damage when VE.Bus BMS cuts the charge to LiFeP04 batteries?

I understand that under certain conditions (over temp/over voltage etc)the VE.BUS BMS will cut the charge from the alternator to protect the LiFeP04 batteries. However, effectively cutting the alternator off when under way could potentially damage the alternator. I have seen one solution which was to also connect a small lead-acid battery (with a small continuous load) added directly to the alternator output but this seems to be a bit of a mash-up! Is there a more elegant way of protecting the alternator from a sudden load disconnect?

ColinS asked
billp commented ·

3 Answers

DC Generator as input for SmartSolar 150/85

Hello community!

First time user of Victron products. So a big hello to all.

We needed a charge controller in tandem with our new DC Generator model to have the abilty of charging all battery chemistries, with the added features Victron has to offer in that range.

So we decided to test a SmartSolar 150/85 with the dc generator as a replacement to pv input.

Not knowing if it would work or not, we are pleased with the results! Firstly, no magic smoke(thank God for that). Generator started automatically when LiFePo4 batteries reached a preset low SoC. We used a 48v 100ah bank for the test. The generator produced 70vdc @ 40A(limited for the testing). SmartSolar did the job as expected!

We will continue testing over the next few days and upload a video of the end results.

The main purpose of our DC Generators is to be used as a backup source in case of low solar production in off grid situations, telecommunication sites, boats, rv's etc.

All of our dc generators and AutoGen controllers connect through wifi and can be monitored via our mobile app.

So now, Victron can add DC Generators to the solar, wind, hydro list of input sources to their MPPTs.

DC Generators asked
DC Generators edited ·

2 Answers

Argofet and MPPT compatibility question

HI guys,

Can someone with expertise with the Argofet help me, I want to add an Argofet to split charge my VRSLA start battery and my LFP house bank. Easy so far. I want to connect an MPPT controller to the input of the FET and utilize the alternator energize circuit to tell the MPPT that there is voltage. The solar controller needs to see voltage at the battery terminals or it wont start charging.

This is what I had in mind, will it work?


The following is from Victron ArgoFet documentation...

Alternator energize input
Some alternators need DC voltage on the B+ output to start charging.
Obviously, DC will be present when the alternator is directly connected to
a battery. Inserting a Diode or FET splitter will however prevent any
return voltage/current from the batteries to the B+, and the alternator will
not start.
The new Argofet isolators have a special current limited energize input
that will power the B+ when the engine run/stop switch is closed.

Jafa Russell asked
Jafa Russell commented ·

2 Answers

1 Answer

VE-Bus-BMS-example alternator question


I've been looking at this system example

and I'm a little concerned about the alternator setup. It essentially shows the alternator connected to both a starter battery (assume some sort of lead acid/AGM) and the LiFePO4 batteries. Should the alternator be regulated in some way? Otherwise what's the voltage you are applying to the Li batteries? Should one use a smart regulator like a Balmer or Wakespeed which can be setup to have the proper voltage profile for the lithium battery but then you would have to deal with the starter battery as well. I suppose the starter battery gets such little use that if it's an AGM battery then the Li profile from the regulator should keep it reasonably charged. Another possibility is the Sterling AB12130 Alternator-to-Battery charger which deals with Li batteries as well as the starter battery. Is the profile that the Victron Li batteries require documented somewhere?

Thank you,

billp asked
billp commented ·

1 Answer

Alternator to LifePo4 batteries

What is the best way to deal with the "studied alternator" problem, after switching to LifePo4?

Just installed 2x 4x Winston 200Ah cells, everything works, exempt from the alternator, that has not been connected yet.

What is the best way to do this, so it doesn't burn off?

Have looked at:

Buck-Boost DC-DC Converter 50A/100A - Nope not going to happen to expensive!

Orion-Tr Smart DC-DC Charger Isolated - 25A way to slow.

Sebastian W. asked
Justin Cook - Bay Marine Supply USA commented ·

3 Answers

Truck alternator over MPPT?


I am looking for a way to have my second truck alternator charging my lithium powerwall.
Currently I have a multiplus, a bluesolar for the solar panels, a BMV, and a CCGX setup.

Would it work if i get a second MPPT and use the alternator output as source for the MPPT?

Or what would you advise?



betz asked
Jex answered ·

3 Answers

12 v alternator sizing

I am installing 6 12.8v SuperPack batteries to be charged by a Balmar 200 amp/externally regulated. Good size alternator? Sail boat =short engine time running.Currently have 100 amp Balmar? external reg. Thanks

tito asked
tito commented ·

3 Answers

Charge a 12v+12v series conected batteries (24v) with van alternator (12v)

Dear forum.

I have two solar panels 180w 12v that I will connect through a victron MPPT solar smart 75/15 to charge two 115Ah 12v batteries series connected (24v).

Could I charge my batteries with the DC-DC 12/24 480w 20A from Victron? Is there a better option?

Thanks a lot!!

pepvan asked
pepvan commented ·

1 Answer

Orion-Tr Smart DC/DC control and grounding clarification


I am building a 24V setup very similar to the victron van install ( on a old Mercedes Benz truck (no smart alternator).

Instead of the Buck Boost, I will use the new Orion-Tr Smart 24/24-17A (400W) Isolated DC-DC charger behind a Battery Protect.

My negative bus bar and the enclosure of the MultiPlus are grounded to the chassis using 4mm2 wire.

The manual of the Orion-Tr Smart ( states on page 4:

"Remote on-off
Use the remote function to enable and disable the converter remotely with the remote on/off connector or using the
VictronConnect app. Typical use cases include a user operated
hard wired switch and automatic control by for example a Battery
Management System. If the minus of the service battery is not at
the same potential as the minus of the alternator or starter battery
an isolated remote on/off cable between the BMS and the on/off
port is required, see chapter 4.4 for details.

This should not be the case in a vehicle, but the on page 10, Figure 4:


there is an isolated remote on/off cable shown.

So here are my questions:

  • Is it correct to ground the negative bus bar and the enclosure of the MultiPlus to the vehicle?
  • Is it necessary to also ground the enclosures of the MPPT, the Orion etc. in such a setup?
  • Basically, I want to use the automatic "engine running" detection mechanism of the Orion-Tr to enable it. In case the VE.Bus BMS triggers the charge disconnect, the BatteryProtect on the charge side disconnects the Orion-Tr to protect the batteries. The question now is, if I also need to deactivate the Orion-Tr to protect it from beeing damaged, like with a MPPT? How would I do this? I have a "Non inverting remote on-off cable, ASS030550200" in my hands. It does not look like the one used in the diagram, it only has three cables (red, black, yellow).


kiko asked
kiko edited ·

0 Answers

Alternator not charging deep cycle battery via Argofet 110.2

I have a Victron BMV 712, an Argofet 100.2, a Victron MPPT 100/15 and an AGM 120amp deep cycle battery. The BMV is not picking up charging current from my Isuzu Dmax 2014 alternator to the deep cycle battery.

Aside from the prospect of 'bleed' from my charging battery, is there anyone with experience in fitting the Argofet that know how much charge I can expect into my DC battery whilst car running?

The principle is that the alternator should be simulatenously charging the starter and deep cycle batteries with minimal voltage drop.

christo64 asked
Justin Cook - Bay Marine Supply USA edited ·

1 Answer

Lifepo4 alternator charging solution feedback needed

I was waiting to see what the new alternator charging solution would be from Victron but seems like the solution is more of a trickle current wise than what I'd like to see. I've got a big bank 32 cells of Calb 180ah @ 3.2v, wired in series/parallel to 24v nominal bank @ 720ah. I need a firehose not a dribble of current for charging [staying at or below .3C charging, which for this bank would be 54a*4 or 216a, regardless of input voltage]. Looking for some feedback on potentially the best way to proceed. All amps below are listed as 12v with 24v in ( ) next to it.

1. Up convert alternator output from 12v to 24v.
2. Protect alternator from overheating.
3. Protect alternator from voltage spikes due to charging circuit being disconnected.
4. Limit charge current to no more than 50% of alternator maximum output.
5. Provide 3 stage charging profiles for Lifepo4.
6. Sync charging with smart solar mppt while driving.
7. Integrate into the Venus GX and provide visibility of current produced.
8. Isolation from starter batteries (dual on F550) to prevent draining/damage.

1. F550 extra heavy duty dual alternators with outputs of 220a and 157a or 377a combined. 50% of this would be 188a (94a) These alternators are also temp compensated to my understanding. (see attached output graph below).
2. Uplink cable 2awg
3. 720ah 24v Lifepo4 bank in basement of truck camper.

Proposed solution:
1. (2) buck boost 12/24 converters 100a (50a) + 50a (25a), combined 150a (75a) installed in parallel within the cab of truck. Initally I will start with a single 100a (50a) buck boost and add the additional 50a (25a) later if everything seems stable charging wise.
2. Uplink cable connects to second Smart Solar 150/85 mppt.
3. Second Smart Solar 150/85 mppt connects to positive and negative bus bars within camper.
4. Second 150/85 mppt would connect to the Venus GX for management.

Ideas, thoughts, feedback?



wikel asked
Tom answered ·

3 Answers

Victron Alternator charging Li Ion Video

I found the new Victron Video on charging Li Ion Batteries very interesting and helpful, but still it was not clear if using a lower amp charger like the Victron 25 amp Buck Boost Converter will help protect an alternator from over heating and burning up due to low resistance of Li Ion batteries?

I have a MB Sprinter with a 220 amp alternator. MB limits charging to 40 amp from what I have learned. I am not in need for fast charging of my 24 volt 400 AH battery so I think 25 amps from the Victron Buck Boost Converter while driving and 20 amps from PV would be sufficient. I just want to be sure the Buck Boost or new Orion unit will keep my alternator from burning up.

Tom asked
wikel answered ·

2 Answers

12/200 alternator shut off

Trying to get my head around how the 12/200 operates and would appreciate any help to educate me ;)

The 12/200 datasheet shows that the 12/200 has a shutoff voltage of 11V which makes sense, but I am missing something in my understanding of how it works to stop overcharging of a lithium.

I also understand the purpose of the fuse to set the current limiting from the alternator (not sure how it achieves this though) - but again, am missing something to see how/when it shuts off the charge to the lithiums (and uses the lead-acid to dump into).

Anybody able to fill the missing gaps for me ?

moiuk asked
Daniël Boekel (Victron Energy Staff) answered ·

1 Answer

Using a Cyrix-ct 12/24-230, for 2 different battery banks

Hi All. The scenario is as follows:

We currently have a Cyrix-ct 12/24-230 connected in a Toyota Land Cruiser 79. This Cyrix charges the batteries in a caravan being towed (Via Brad Harrison connectors on caravan A-Frame). This works perfectly.

We now have a second bank of batteries in the back of the Land Crusier (2 x 125Ah). These power fridges in the back of the Land Cruiser.

Can the charging power of the Cyrix be split to charge the Land Cruiser's 2 batteries AND the caravan batteries (2 x 230Ah) simultaneously.... I have Argofet isolators available as well that can be fitted, if this solves the problem...


Matt_RSA asked
Martijn Coster (Victron Energy Staff) answered ·

1 Answer


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