Need the solar/power pros to weigh in

TantoTrailers

Well-known member
As my buddy says..."Let 'er rip tater chip!" I will wire it up and mod if needed! Ty for all the valuable input I seriously would way more lost than I am now without it.
 

Buddha.

Finally in expo white.
Here is the 100W version.


Spec sheet here.

I'm following this thread because I have similar questions about my own setup.

I want to charge my 2 6v trailer batteries(215ah). Unlike the OP who just wants a trickle charge I want to have as much charging as practical/possible. Is this the charger I want? It might be a little on the big size? I want to leave myself open to going with 4 6v batteries in the future if I decide to.

I'd mount it in the front compartment of my trailer maybe 4' away from the batteries.

According to Victron's spec sheet listed above input voltage to the charger from my truck can be as little as 10 volts and it will still charge my batteries quickly?
Looking at a voltage drop calculator I see 40amps going through a 50' run(+/- total circuit) of wire I could go with a little 12 gauge wire and it would still be over 10 volts to the charger. There must be some downside to using that small of a wire? What would be a more appropriate gauge of wire? How big of a wire can that charger physically accommodate? It's hard to tell from the pictures but it looks like 10 or maybe 8.
 

shade

Well-known member
Looking at a voltage drop calculator I see 40amps going through a 50' run(+/- total circuit) of wire I could go with a little 12 gauge wire and it would still be over 10 volts to the charger. There must be some downside to using that small of a wire? What would be a more appropriate gauge of wire? How big of a wire can that charger physically accommodate? It's hard to tell from the pictures but it looks like 10 or maybe 8.
Here's the manual: https://www.victronenergy.com/uploa...art-Charger-Isolated-EN-NL-FR-DE-ES-SE-IT.pdf

Since the heaviest wire they spec is 16mm² , that works out to between 4-6 AWG. Since it hasn't been released yet, I'm not sure you'll get a better answer until it's in someone's hands. I have a 12/12-30 on order, and was told it would be six weeks or more before delivery.

Here's Victron's conversion chart: https://www.victronenergy.com/upload/documents/AWG to Metric Conversion Chart.pdf
 
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Buddha.

Finally in expo white.
If I run solar(~300watts) as well as dc-dc charging do the solar charge controller and the dc-dc charger work together? Wouldn't one confuse the other about what the actual state of charge is?

I was looking at this product to be my dc-dc charger and my solar charge controller. It's max input voltage is 32vdc so I'd have to run the solar panels in parallel because it looks like a 12v panel may put out as much as 18 volts, two in series may damage the charger I think?
 

dreadlocks

Well-known member
Victron Products are starting to talk to eachother and share info via BT networking, my solar already gets battery voltage from the battery monitor and next firmware will allow multiple chargers to synchronize charge stages via bluetooth, I have to imagine the new DC charger they announced will also join in on this capability sooner or later if not right out of the box.
 

shade

Well-known member
Victron Products are starting to talk to eachother and share info via BT networking, my solar already gets battery voltage from the battery monitor and next firmware will allow multiple chargers to synchronize charge stages via bluetooth, I have to imagine the new DC charger they announced will also join in on this capability sooner or later if not right out of the box.
That's how I figure an all-Victron system will work, but if not, I'll manually shut off alternator or solar charging, as needed.
 

dwh

Tail-End Charlie
Multiple chargers - even if they don't talk to each other - don't butt heads or confuse each other. None of them actually know what the battery state of charge is. They each read battery voltage and do what they do based on that.

It's like having multiple compressors hooked to one big air tank, and each compressor has its own pressure switch. If the pressure (voltage) is low enough, all the compressors (chargers) are pushing air into the tank. As the pressure rises, whichever compressor has the pressure switch with the lowest setting stops pumping air into the tank, while the compressor with the switch with a higher setting keeps pumping.

Of course, chargers also have timers, to hold a higher voltage for a while after the battery reaches that point, to allow the battery to slowly absorb all it can. Holding a high absorb voltage doesn't much matter for solar or dc-dc...it stops when the sun goes down or the engine shuts off. It matters for shore chargers since you don't want to hold absorb voltage for days non-stop.
 

luthj

Engineer In Residence
You are not going to cause trouble for a lead bank with parallel chargers. The bank will accept what it wants, and all the chargers are trying to reach their setpoint voltage. At some point the current tapers, and all the chargers will cut back current.
 

shade

Well-known member
I should've mentioned I'm installing an LFP system, so having any confusion from chargers running at higher voltages while at 100% SoC would be a problem. Maybe it won't happen, but I'll experiment before finding out the hard way.
 
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TantoTrailers

Well-known member
Alright tonight got crazy, I swore a bunch and got really pissed at myself for putting everything in the smallest possible space a bunch of gear can fit but it’s all in and it looks nice......not sure if it’s working right. BMV is showing 69 AUX INPUT across the screen after I set the AH. In the app it’s showing everything fine(assuming). IP67 is showing up fine in the app as well. When charger was disconnected and light bar on using battery I was showing -Amps in the app and when charging I was showing +Amps (looking at BMV) so I think I have everything wired correctly, it’s all hooked up according to the diagram below. I will be leaving for a work trip (no trailer unfortunately) till Sunday so I’m going to unplug everything and disconnect the battery just so nothing weird happens when I’m gone but what do you guys think? What’s with the display? Did I miss a step or did I mess up the punch down crimp on the RJ11?

6870E7FC-5D19-4BBF-8146-1DA0ACE2987C.jpeg

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AC68E695-9FAC-4347-B88F-DB038BE8673C.png
 
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TantoTrailers

Well-known member
Welll....RTFM moment. Page 5 of the manual step 1.2 explains what AUX INPUT is. I needed to select the AUX monitor cable function. As soon as I did that it showed my voltage and then a few seconds later the midpoint deviation alarm started going off with 99.6% deviation? I have not yet calibrated the BMV but I just want to make sure I don’t have a serious problem either with the battery or my wiring. Any ideas?

now that I read even more....I should be monitoring “Start” battery with the Aux input....right? Not exactly clear in the manual but the wiring diagram says starter/aux battery monitoring for the diagram I’m using...
 
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dreadlocks

Well-known member
sounds like you set aux input to midpoint which is only for multi-battery banks.. if you just have one, you either dont use it (set it for starter battery, will show zero v if you dont have a 2nd battery to monitor) or get a temp probe sensor if you want to provide temp readings to your victron chargers.

seems to me that you might not have the voltage probe wired up correctly and the main battery voltage sensor is wired to the aux input and not the primary input on the shunt
 

TantoTrailers

Well-known member
I think it’s hooked up right. I followed the instructions in the pic. I changed the input from mid to starter and it seems happy now!

7429EB31-655D-47A9-A652-923B40679192.jpeg

15811141-4828-49B2-8ED8-BFEAAEBA05BB.jpeg

02A69F0E-35D8-4CBC-9D44-9055EC4444C2.png

That first little guy next to the RJ11 is B1 so I’m hooked up to spec :)
2C615D57-1470-4F74-A55A-1BDDD2BC4F85.jpeg
 

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