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dc dc converters

2 DC-DC isolated converters connected in series to provide a dual power supply



I have a question please. Is it safe to connect two isolated converters in series to achieve -/+12V dual power supply? Is it safe to connect the negative converter output terminal of the first converter to the positive output of the second converter? The outputs are isolated from the input.

The product is Victron Orion-Tr 48/12-30A (360W) Isolated DC-DC converter

Thank you.

emilijaz asked
emilijaz commented ·

1 Answer

12/24 Buck Boost --> 3x 24/48 *Isolated* Converter --> MPPT SCC --> 33v Charging [Now wired and sort of working]


I've got a very particular DIY Nissan Leaf 24v battery configuration and their operational voltage is about 28-33v and I'd love to get more out of my Victron 100/50 12/24 Buck Boost Converter instead of only being able to charge them to 30v (buck boost limit).

-- I do also have a 900W solar array and MPPT which provides the desired 33v charge but during the winter it is not enough to keep the 8kWh battery above 50%.

If I run the buck boost output through a step up converter then through an MPPT do you think it's possible these components will work in a way which will allow me to output the desired 33v charge output via the MPPT?

- in this configuration, will the buck boost endlessly provide output of 50 amps if programmed at 30v output charge in it's software?


1x Victron 100/50a 12/24v Buck Boost Converter

3x Victron 24/48v 8.5a DC to DC Converter (to achieve approx 50a @ 24v)

1x Victron 150/60 MPPT SCC

As I understand it, because the Orion DC DC Converters are isolated and do not have a current path between the input and output, as long as I set the buck boost to below 30v (it's max) it should not be able to see any voltage higher than the input side of the Orions, and therefor should continue to output a constant desired voltage <30v.

Pictures below to get an idea of what this will look like. I'll be doing a test wire and config before the final mounting of the board happens.

This is an "upgrade" to my system that is already working perfectly and runs a 240v mini split AC, 120v induction cooktop and water heater, as well as all 12v devices.

If this does not end up working I will be moving in the Safiery Scotty device direction.

I'm really enjoying playing around with this very unique system, it's been a fantastic learning experience, much more learning to be done for this humble DIYer.

Thanks in advance!





Update -- I wired everything up and was able to get the buck boost to send current through the Orions and MPPT however it keeps cycling after about 20 seconds of current.

Example is 20 seconds current then off for 20 seconds then back on for 20 seconds etc...

Also, 1 of the Orions is about 10 degrees hotter than the others. All of the output and input voltages are the same, or at least within 0.1v.

I'm enjoying the experiment and would love to know if anyone has best practices for having 3x Orion 24/48 dc dc converters wired/configured to share the load equally.


Below is screenshot of all (or some) of the converters and mppt (Alternator’s MPPT) working up to 700+W (desired is closer to 1200W though, which the 3 Orions should be able to provide, unless the inefficiencies stack and then perhaps I’m at limit)


I can hear the converters "tick" when they switch on and they aren't quite in synchrony, I imagine this causes problems with load sharing or even one or 2 of them not activating.

Can I wire them in some way with the remote switch to all come on at the same time?

Should I wire them all directly to one another instead of using bus bars? i.e. wire positive to positive and neg to neg?



I raised the output voltage via the rotary switch on one of the devices from base of 40v to about 42v to start various tests and the buck boost is now constantly delivering around 20 amps current at 30v.

I also have been testing temperature differences and it seems that whichever Orion is set to the highest output voltage, it is the unit that "does more of the work" (gets the hottest).

I ended the test for the night by maxing out the output voltage dial for all 3 Orions to about 60v, which led to still consistent current but a higher level that any previous tests.

The tests concluded with an output of 885W. I'd still love to figure out how to utilize the full current of the 50a buck boost though. (1200+W ***update***if the efficiency losses dont stack)


A DC current clamp meter shows the buck boost outputting about 45 amps but the MPPT after the 3x Orions only outputting about 30a.

More testing to come tomorrow.

Update *** i’ve got the system now operating at a consistent level with an output between 700-800W.

Does each Orion converter have a 11% efficiency loss which would be 33% cumulative loss which is why I’m seeing about a 30%-40% drop in output across the system?

thirdeyesamuel asked
kevgermany answered ·

2 Answers

Does the 11% Efficiency Loss of 24/48-8.5a Orion Converter stack when paralleled? (I've got 3 in parallel, is that a 33% loss?)

I'm running 3 of these 24/48 8.5a Orion Converter's and a dedicated 150/60 MPPT (for alternator charging) after my 1200W Victron Buck Boost Converter. The Orion's + MPPT output is about 700-800W+. This would appear to be a result of their 11% individual efficiency losses stacking.

Is this in fact how they work? Thanks!

***this is an experimental system necessary to achieve the 33v charging output needed for my high 24v (28-33v operational voltage) Nissan Leaf battery system.

I'll be continuing testing and checking shared load via temperature and dc current clamp metering.

If I decide to go another direction it will be with a Safiery Scotty 3000W device.



thirdeyesamuel asked
markus answered ·

1 Answer

Dc to dc charger drawing on car battery

Is there any way the dc to dc charger is weakening my car battery. It's a new battery and I have to jump it everyday

mitch asked
Matthias Lange - DE answered ·

1 Answer

Preventing Alternator Burnout with DC-DC Charger

I have purchased a Smart DC-DC 12/24 15 amp charger for use on a small boat.

The alternator on the 60HP outboard puts out maximum 21A.

The start battery will be a 75AH Li.

The plan is to charge a 24V 200AH Li battery (used to power a trolling motor) while the engine is running.

I am concerned about overheating the alternator when the motor is running at idle and producing less amperage than the rating of the DC-DC charger.

If the alternator is only producing 5A at idle but the 24V trolling motor battery is discharged and the charger is trying to pull its maximum of 15A, do I have a potential problem?

If I use a Lead-Acid start battery do I avoid potential problems?

Thanks for your help.

kajones99 asked
kevgermany answered ·

1 Answer

Orion-Tr Smart DC-DC Chargers died?

I recently installed a pair of Orion-tr smart dc-dc chargers to charge my lithium bank and they were operational during my first test run. (They weren't quite as powerful as I expected, but were working).

Because the RV is primarily parked (at this time of year), I often connect a NOCO Genius 12V charger to keep the vehicle batteries from going dead.

Between the install / first test and a drive today, the 12V charger was connected for a couple weeks.

I did not isolate (breakers) the Orions during this time and wonder if there is any way that the starter battery charger could have killed the Orions? I would have expected that they would either accept the charge or reject it, but not that they could be damaged.

They are completely unresponsive. No changing. No blue tooth. No visibility on the app.

Does anyone have any advice on what the issue is and / or if there is a way to reset them?

seeinghuman asked

0 Answers

Connecting two Orion-Tr Smart converters in parallel

I want to connect two Orion's in parallel to charge twice as quickly when driving. However, I've read that in order to do this you need to connect a 'hot wire' from the ignition to manually turn the units on, as using the voltage sensing can cause issues if there's a slight lag between the two units, causing one to not turn on.

I understand how to connect the two units in parallel, but how do I connect to the ignition to act as a switch? I have a Mercedes Sprinter, not even sure where to start - thanks in advance! I presume there's no other way to charge quicker than 30A? I have a Euro 6 engine so can't use a standard VSR.

nancybeaumont asked
nicetrip answered ·

2 Answers

Incorrect voltage reading on DC-DC Charger


I have an Orion 12|24-15 Non Iso DC-DC charger. Its input is a 12v starter battery on a Sprinter and the output is a 24v Li-Ion pack and they share a common ground.

I have been seeing strange charging issues and over-voltage alarms. On closer inspection the voltage shown in the app for the Orion doesn't match what I measure at its terminals with a meter.

These 2 images show the exact same time but a difference of 0.35v. Its been worse than this on other occasions and reads both under and over randomly.

Has anyone seen this kind of issue before on a DC/DC? Its on the latest FW, could it be a fault in the unit or my setup?



Additional Info

All Bluetooth devices have the latest firmware available in the Victron App.

As I am measuring at the terminals I dont expect cable or connector losses to be an issue here. I also have a good bit of other Victron kit on the same 24v side which all agree with the multi-meter consistently under < .1v difference . All the kit is connected on the 24v Side via a Lynx distribution unit with cable well within its ratings. Connection tightness double checked. As mentioned earlier sometimes the voltage in the DC-DC app reads over sometimes under and it seems to move around day to day.

Heres a comparison of readings:

Device Reported Voltage
Orion 12|24 - 15 (Output) 24.2
MPPT Smart Solar 23.88
Orion 24|12 - 30 (Input) 23.9
Smart Shunt 23.85
Multimeter 23.85

Any advice or questions welcome. Many Thanks!


marv2097 asked

0 Answers

Buck Boost DC-DC converter not found by TSConfig

Despite doing everything including down loading drivers, I cannot access the TSConfig, someone else had the same issue and came on the forum inJuly this year but got no replies. Please help!

hoeymick asked

0 Answers

Orion DC-DC Converters Non-isolated, High power vs Orion IP67

I'd like to run 12V loads in a motorhome from a 24V battery bank, and the loads should not exceed 70A. Hence I could use an Orion IP67 24/12-100, or an Orion 24/12-70 (Non-isolated, High power)... Which should I choose, and why? (Basically, how are they different?)

hookem asked
nicetrip edited ·

1 Answer

Buck-Boost in Non Euro Vehicle

Any issues in using a 100A Buck-Boost to charge Lithium Battery Bank in a 12V vehicle without intelligent dynamo? Needing 100-120A charging for 1000+AH battery bank from vehicle's (Ford) 397A alternator. Thanks

mbdrenth asked
myhomebuzz answered ·

1 Answer

DC-DC Non-Isolated Charger - Charging Disabled

Morning, Hoping some one can shed some light on my potential issue. I have been revamping my camper van and have installed a DC-DC 12v 30amp non-isolated charger to replace a VSR I had previously. I have also installed a Victron IP22 charger. The IP22 all works as expected and I can see it charging the battery. As a test I connected a Victron IP65 Charger (12v 10amps) I have in powersupply mode to the DC-DC 12v Charger as test before I fit it to the vehicle (I set the powersupply to output over 14volts). Now if the battery is not connected the DC to DC charger says its in bulk charging mode. As soon as I connect the battery it disables the charge. I have double checked all the battery and charge settings and they are correct.

This is my setup for some context :).


drewbie asked
drewbie edited ·

3 Answers

DC-DC Converter: what happens when output voltage is lower than target battery?


I would like to use the Orion-Tr DC-DC converter to charge my house battery from the starter battery. The house battery is also charged by solar.

According to the description of the Orion-Tr DC-DC Conveter it is possible to use it as a constant voltage charger for a secondary battery (e.g. house battery). I wonder what happens when the target battery has a higher voltage than the defined output of the converter? Will it just stop charging? Or will it be destroyed?


[starter batt] -> [DCDC converter, output 13.6V] -> [house batt at 14.4]

patrickschweizer asked
Mike Dorsett answered ·

1 Answer

Dc to dc charger draining starter battery ??

Hi all..

Hope someone may be able to shed some light on this one.

So I am using an Victron 12-12-18a isolated DC to DC charger.

This is how I have wired it :

- Positive from starter battery to input positive on Victron
- Negative from earth point under seat to negative input on Victron
- Positive output of Victron to positive of leisure battery
- Negative output of Victron to negative of leisure battery

Then from the leisure battery :

- Positive to the positive of a 12 way 12v distribution board
- Negative from rear earth stud (drivers side rear quarter) to negative of 12 way 12v distribution board

The issue :

- When on a camp site for 2 or 3 days on mains hook up (there is a battery charger under the seat, charging the leisure battery), the starter battery is losing voltage to the point where I can't start the van ??

Is this being caused by the DC to DC wiring / vsr or maybe something else.

Your help would be much appreciated - I am completely lost !



andyjturner asked
alanr answered ·

8 Answers

Buck Boost and MP2 with connected starter battery (Terminal E)

Hi there,

I've been searching around the community and asked my dealer regarding the following connection but couldn't get my head around this particular situation.

I am instaling a MP2 and a buck boost in a vehicle 24V installation. I would like to use the "starter battery charge" ruction of the MP2 (E-connection) for when the vehicle is connected to "shore power". Also, I would liker to use the auto detection of the buck boost for charging the LiFePo cells.

My question is now: How can I make sure that the buck boost will not switch on when the MP is charging the starter batteries? The he voltage threshold is probably not sufficient and is the vibration detection sufficient? Or is it best to install a fixed input to the alternator via the purple connector of the buck boost?

Thanks for our input and help :-)


lechrisl asked
Mike Dorsett answered ·

1 Answer

Victron Buck boost low input voltage. Will not turn on. Need help.

Hi. This is my first post. I have a Victron Buck boost 50 amp and the buck boost is not turning on. I went into the TSConfig software and the input voltage is at 0.7 volts. I checked my aux battery and the battery has 12.8 volts. I am running a 4 gauge positive and negative wire (8feet long )from my starter battery to the buck boost. Please let me know what you think and what I can do. Thanks.

justin-dillon asked
justin-dillon answered ·

4 Answers

Using both a DC/DC and a MPPT Charger


I am planning on using the Victron Orion TR-Smart 12 12 30 Isolated to charge a LiFeP04 House Battery from the Start Battery of an outboard Alternator.

However, I am also planning on adding solar, to top up the house battery when we are not running the outboard. For this purpose, I am considering the Victron SmartSolar MPPT 100/30, but I am now wondering how the charging would switch between the two systems? Does Victron have a Smart integrated MPPT/DC2DC Charger? Or can it be achieved differently with Victron devices? I know of other branded products that do this.

Can I connect simultaneously both Victron units to the House battery?



adric asked
tdsmith541 commented ·

3 Answers

Buck-Boost Temperature via CAN-Bus


I might to know the answer already, but is there a possibility to get the battery temerature which is on the CAN-Bus into the Buck-Boost for low temperature cut off?

Thanks for your help



dirkmuc asked
kevgermany answered ·

1 Answer

Newby needs help with orion dc-dc charger on lifepo4

Hallo, I have a persistant problem with my setup. Somtimes the voltage of the lifepo4 falls under a treshold to which the BMS shut down the akku output. After that the orion 12/12-18 does not load the akku at all - the charger cannot heave the akku over that treshold again. Other chargers can. I have a small dedicated lifepo4 charger that does the job without problems.

Settings on the orion are all set to lifepo4.

Does anybody have experienced similiar problems, and maybe found a solution?

I 'am grateful for any hints...

dukeofhazard asked
kevgermany answered ·

1 Answer

Orion-Tr DC-DC Converter Isolated - Remote on/off question

I have the non-smart version of the Orion TR 12-30 DC-DC Isolated charger in campervan. My positive input wire is connected to one of the open locations on the battery of a MB sprinter van. I have the input and output grounds going to a common negative buss that is grounded to the vehicle chassis.

I'm little unclear what to do with the jumper plug. From my understanding this model doesn't have the engine detection on mechanism so a wire form the ignition switch will need to be ran to it to tell it when to turn on? I currently have the jumper wire in and Blue Sea Systems battery on/off switch I have to turn off power to the auxiliary battery banks does not kill the power which indicates that my auxiliary system is getting 12v from my vehicle battery via the DC-DC charger because the jumper is in?

nkhofer asked
jeroend answered ·

1 Answer

PIlote Buckboost introuvable


je viens de changer de PC et je n'arrive plus à accéder aux Buckboost 25 ou 50. Lorsque je le branche sur la prise USB, j'entends qu'il détecte quelque chose mais les ports COM disponible ne s'affiche pas.

Lorsque je vais dans le gestionnaire de périphérique je vois bien le périphérique mais il me dit:

- Les pilotes de ce périphérique ne sont pas installés. (Code 28)
- Il n’y a pas de pilotes compatibles pour ce périphérique.

Heureusement mon ancien pc fonctionne encore...

Ma config: Windows 10

Si vous avez une idée et/ou déjà rencontré ce problème, et que vous avez la solution, ...

En vous remerciant d'avance

procamscop asked

0 Answers

Use MPPT for another utility
Hello, I was wondering if it was possible to use an MPPT to convert a 48v battery to 
12v. A simple DC-DC converter is not enough for me because it does not generate enough power for my use (500 / 600W) Thank you :)

mathew asked
JohnC answered ·

1 Answer

How to charge a starter battery from leisure battery?

Goal : I want to use my vehicle's indoor lights and ventilation during the night (3A 12V).

Setup : I currently have an independant solar and battery setup (700W solar 160AH of usable LiFePO4 battery)

Proposed solution : I think I could use an Orion-TR 12/12-9 converter taking power from my leisure battery and use the cigarette lighter circuit to charge the starter battery (15A fuse so everything seem alright). (The vehicule manufacturer said it's ok to let the car at "on" for long periods if I charge the battery.)

- Will it work?

- If I start the engine and the alternator is working at the same time as the converter, will it cause problem? (alternator and converter in parallel, seems ok from the manual from the possibility of paralleling multiple converters)

- Have I other solutions?


mathieu-dubuc asked
scraggs edited ·

2 Answers

DC DC Converter Parallel & Single Setup

I am about to wire 2 24-12 70 DC-DC Converters in Parallel to power a Mover for a Caravan. But this 140Amps are basically just needed when I use the mover. For the rest of the time, 70Amps is already more than I need on the 12V section and I would like to save standby usage of 2 units when one is sufficient.

Can I install a switch to operate only one DC-DC converter, meaning just one converter is powered without getting problems with current going from the output of the powered converter to the one that is not powered?

Best Regards

nomad asked

0 Answers

Why Steady 'Green LED' on Vic 12/30 DC/DC Orion If Setting is on "Charge" and Tundra Is 'off'?

'05 Tundra, on Battery Tender, Smart Alternator, motor off, DC/DC setting on 'Charge' but steady green LED is on....when I open the breaker the green LED goes out and no 'output' then shows on the Vic Connect DC/DC screen....

2 possible meanings according to Victron....In 'Power Mode', it is not or in " 'float stage' [battery charged]".

Sooooo, what is happening?


phillip-buttolph asked

0 Answers

inclinaison convertisseur DC DC


Je n'ai plus de place pour un convertisseur DC DC. Est-il possible de le mettre en vertical mais incliné à 90 degrés (c'est-à-dire que les inscriptions en façade seraient inclinés à 90 degrés, les câbles seraient branchés sur le côté à droite au lieu de en-dessous). Est-ce qu'il y a une inclinaison à ne pas dépasser ?


roucoups asked
Thierry Cortassa (Victron Energy Staff) answered ·

1 Answer

Campervan Schematics


Hi All,

I have finished my first revision of the campervan schematics, I am sure I would have forgotten a few items (such as the Dometic fridge, a shower solution etc), but this is the general installation. I wanted some people to check it over and to see if everything looks legit in terms of wiring etc. I suspect the solar wattage should be enough considering I have the DC-DC charger? Also in terms of AC power, can someone advise on a suitable distribution box that will work seamlessly with the Multiplus and the correct wire sizes for this also please?

Let me know if anything looks wrong. I plan to fit what I can and get it approved by an electrician.

campervandan asked
kevgermany answered ·

5 Answers

Isolated or Non-Isolated For An RV

I need to install a dc-dc charger in my trailer. I tow it behind my truck and use the truck's alternator to charge the trailer's battery en route (via an anderson plug). The dc-dc charger will be grounded to the trailer's LiFePO battery. the truck's battery is grounded to the body and frame. Should i install an isolated or non-isolated dc-dc charger?

Also, can i create a custom charge profile with both versions of the dc-dc charger?


psea asked
psea answered ·

1 Answer

Victron 12/12 30 cycles on and off (input voltage drops)

I have a 12/12-30 dc to dc charger hooked up to my battery in my car. It has worked perfectly for three months but yesterday it started cutting out. It would work for 5 min and then input voltage would drop and it would turn off then input voltage would go back to 14.2v and it would turn on again and repeat doing this over and over again.

i have 6awg wire ran from the battery to the unit and from the unit to my house batteries, fused at the starter battery and the house battery through a lynx distributor. Not sure what the issue could be so any assistance would be helpful

ryantwomey asked
basil katakuzinos answered ·

1 Answer

Orion-Tr isolee 12/24 15A


J'ai remarqué que le câblage de mes 2 convertisseurs orions étaient particuliers.

Ils rechargent un parc de batterie en 48v.

1- Le Négatif du 24v ( sortie ) était branché sur le Negatif 12v ( entrée).. cela peut endommagé les batteries ?

2- que signifie isolated pour mon cas ?

3- pour la recharge du parc en 48v les 2 orions doivent être réglé sur quelle tension exactement? 27.6v ?

Merci de vos conseils

patrice34 asked
patrice34 answered ·

6 Answers


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