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Cyrix Battery Combiner

Cyrix CT-120

I have a cyrix ct-120, I think it works perfectly. I specify that I have checked all the connections, that I have done the tests that you recommend.

When I disconnect my starter battery from terminal 87 of the cyrix, I have a voltage of 13.1V. When I reconnect the starter battery, the voltage drops from 13.V to 12.4V.

So I have questions.

Is it normal that the voltage drops immediately after everything I connect terminal 87 while the cyrix has not closed?

Is it normal that when I turn on my engine and the alternator does indeed supply 14.8V, the voltage on terminal 87 remains around 14.6V?

Or quite simply a defective mass in the installation can it cause these voltage measurements which seem abnormal to me? I specify that I have checked that terminal 86 on cyrix was on the general mass of the installation

Best regards

lefeuvre asked

0 Answers

Cyrix continuité des « moins » communs

Bonjour, je suis sur le point d’installer Cyrix, shunt 50/500 et Globallink dans mon bateau en acier. J’ai constaté que la continuité des « moins » communs de mes deux parcs 24 volts n’était pas parfaite : je trouve (de mémoire) une cinquantaine d’ohms. J’ai lu que çà suffisait pour retenir la continuité, lorsque la résistance est très faible ainsi. Toutefois j’ai l’impression que cette continuité doit être excellente pour installer un Cyrix. Je me propose de mettre en place un nouveau câble de grosse section entre les deux « moins » pour parfaire cette continuité. Je n’ai pas suivi visuellement tous les câbles si bien que je connais mal la liaison de ces deux parcs et j’ai une petite appréhension avant de parfaire cette continuité. Est ce utile de procéder ainsi ? Y a-t-il un risque du fait des liaisons existantes mal connues ? Merci. Pepet.

Rousset Michel asked
Rousset Michel answered ·

3 Answers

Solar & Alternator Charging

Hello Community, I recently boat a sailboat and the electrics are shocking to say the least and am rewiring the whole boat from scratch. We are also adding Solar Panels and I would appreciate it if someone could confirm whether the setup I have created is correct?


The expected outcome is that when the outboard is running that it charges both batteries but when the engine is off it prevents the discharge of the starter battery.

Any feedback and comments and advise whether I should use any additional equipment would be greatly appreciated.


seaesther asked
trevor-bird answered ·

2 Answers

Where to install fuse for Cyrix-ct 120A?

Hi all,

I have a question about where to place fuses when installen a Cyrix-ct 120A? The diagrams show only a fuse installed between the house battery and the Cyrix, shouldn't there also be a fuse between the starter battery and the Cyrix? As present in the wiring diagram of the Blue Sea ACR (in my opinion similar to the Cyrix-ct). Can anyone help me with these questions?

Best regards,

Lucas van de Voorde

lucasvdv asked
Rousset Michel answered ·

2 Answers

cyrix-ct 12/24-120 two battery and solar system

Please, is it problem for cyrix -ct 12/24 120 if it work with two battery and solar system ( boat ) .

Because solar system charging battery all day , and cyrix device stay close for the long time!

Is it problem for the cyrix device , if yes what we must do .

Best regards

imasar6 asked
bazbaz answered ·

3 Answers

PV system (MPPT + LiFepo4) + AGM - how combine for standby operation


I set up tiny pv system with victron MPPT solar charger + victron lifepo4.

System work great day charge - noon discharge but i”m lacking ability to have emergency power (like ups) that will allow me work offline in case power outage (lifepo4) is in constant charge or discharge so i can’t rely on power stored inside when i have couple days of shade - lifepo4 is discharged and i”m working from grid -and this is what i want .

I would like have separated battery just for storage power only to use in case real outage. I make decision - now we have serious condition - i remove all non esential dc load and switch to backup

battery to power my computer.

I bought for that victron agm 110ah.

What will be the best way to combine this AGM as backup so it will be keep fully charged but wont be discharged until I decide?

first part is easy - i just buy isolated dc/dc charger and make it constantly recharge my AGM from that liion battery that is tied to solar but how to connect inverter / dc load?

hardware changing wires to agm seems like bad idea.

i saw boat switch but all of they have mode For combine both batteries - Im afraid how they respond when fully charged agm is connected to fully depleted 100ah lifepo4.

I seen victron have something like diode combiner - does this will be good for my use case?

or buy two isolated dc-dc chargers and hook one of them in way it recharge agm from lithium and second lithium from agm and then just add double throw switch?

in normal mode it will be charging agm - in reverse it charge lithium - that way i left all my load connected to lithium.

any ideas?

opzsgu asked
Mike Dorsett answered ·

1 Answer

Cyrix CT always hot and draining both batteries

Hello. I have a very simple install in my 4x4 (Mercedes ML 320). I have a normal acid extra battery in the back of my car, only for few equipments. I realize in the last days, I am not moving the car so much, the voltage indicator for the "service" battery was in 11.9 (with the tester, 12 volts, very few, even after driving for about 2 hours in one week ago), and the starter battery was also similar (12.1 volts). The batteries are "separated" well, not moving power between one and the other, just the Cyrix CT is always "warm". Even after a night, if I touch the Cyrix, is a little warm. I think is always using "a lot" of power. I know, I can solve it using a switch and disconnecting the positives, but is really the Cyrix using "a lot of power" in stand by and I need to disconnect it ?

Here a picture and a explain....

Pin 87 = To service/second battery (one meter away with a fuse)

Pin 30 = To main car power supply, taking the power from the cigarette lighter from the back of my car.

Pin 86 = To a common negative.



Today I am going to make more test, I will put and amp tester between the Cyrix and the "main battery" and the same with th service and I will take measurements about how much amps and running..

Thank you

Hipolito Gonzalez asked
volknkn answered ·

4 Answers

Cyrix Li Ct

Hi Victron Community* On a customer's boat, I connected the alternator with a Cyrix Li ct to the lead-acid starter battery and to the Li batteries with integrated BMS (third-party product). I set up the "Charge disconect" of the CyLiCt using a simple on-off switch to manually interrupt the charging of the Li batteries. Now the regulator of the alternato has broken. The starter batteries were cooked with 16V. My questions now for confirmation: Can the CyLiCt be used in the installation type described without Victron BMS and? I assumed so far. And; "Does it absolutely need a DC/DC converter/charge controller to protect the alternator from overcurrents, despite the integrated BMS of the batteries and could the damage have been caused by the missing converter/charge controller? I'm looking forward for answers.

Robert M.O. Seidel asked

0 Answers

Cyrix-CT / Argofet Isolator with Supercapacitors

Hi, does anyone knows can a Cyrix-CT Battery Combiner or a Victron Argofet Battery Isolator be used to connect my w204 AGM starter battery and a pair of 100F Supercapacitors for my audio? My car has "Alternator Management" under my spec sheet.

If possible, which is preferred? Any advice will be greatly appreciated and thank you in advance.

Best Regards

davidw asked
davidw edited ·

0 Answers

Victron Energy Cyrix-i 24/48-Volt 400 amp Intelligent Battery Combiner with LiFEPO4 BMS batteries

Will the combiner work with LiFePO4 batteries with a BMS built in? The input to the combiner will be a 300 amp dedicated alternator which chargers a 100 AH 12DC AGM starter battery. When the AGM is charged (voltage high enough) will the battery combiner start charging the LiFePO4's? Will it stop when the BMS on the LiFePO4 cuts off the connection? Is that one of the design features of the product? It does look like it will, but there is no specific mention of LiFePO4's in the combiner literature. Thanks ahead of time!

sloopjohnb asked
sloopjohnb edited ·

0 Answers

coupleur Cyrix

Bonjour, pour un bateau, j'ai 2 batteries (1 de 75A pour démarrage du moteur et 1 de 50A pour le reste). je les recharge alternativement avec un blue smart IP65. pourrais-je installer un coupleur Cyrix pour ne plus à avoir à changer le chargeur de batteries? merci de vos réponses.

julien-deliege asked
Thierry Cortassa (Victron Energy Staff) answered ·

1 Answer

Cyrix-li-Ct with MPPT75/10


Curently using a solar panel 100W associated with a MPPT75/100 to charge a 12V LiPo 55Ah pack.

This application if for an RV, so I plan to add a Cyrix-Li-Ct coupler to use the vehicule alternator when driving.I just don't know how to do it best.

1) Should the Cyrix-Li-Ct outlet (LiPo side say) be connected directly to the LiPo battery:


2) Or should it go to the MPPT module (so connected to the solar panel outlet) and therefore all charging modes (bulk, float..) are still in in the play?


What is the best way to do ?


Rene Brunier asked
Rene Brunier answered ·

1 Answer

Does the MPPT have reverse current protection from the battery?

I'm looking at a description of the Cyrix Battery combiner and I would like to confirm if this device can be used for protecting the MPPT from reverse current from the battery.

MPPT data sheet does not explicitly mention reverse current protection from the battery side (but mentioned for the solar side). Does MPPT have its own internal reverse current protection or are diodes necessary to prevent damage from back current?

btank asked
kevgermany commented ·

1 Answer

Collegamento Cyrix

Buongiorno, ho bisogno di un'informazione.Io ho un piccolo impianto fotovoltaico a isola in una baita e vorrei collegare un'altra batteria a quella già esistente.Volevo sapere se per questo scopo posso usare il Cyrix 12/24 120A, perché il mio impianto è tutto a 12V.Grazie.

fabiano-vanin asked

0 Answers

Cyrix-Li-Charge or Cyrix-Li-ct

Hi all,

I'm wondering what the difference is between a Cyrix-Li-Charge and a Cyrix-Li-ct.

For my setup I'm looking to put a BMS diconnect between my charger and lithium battery. For this I would need a Cyrix-Li-Charge. But, I have a non-used Cyrix-Li-ct laying around. Is it possible to use this?

I can't find out what the difference really is. I hope I can use the one laying around for this.

Thanks for helping!

robertvn asked
Sarah commented ·

2 Answers

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