Member Since: 21 Aug 2014
Location: Sydney Northern Beaches
Posts: 4906
I have a Victron 12/12-9 amp. One of these is ok. I run into trouble with 2 of them. Still used 2 but bypass that circuit.
https://www.victronenergy.com/dc-dc-conver...s-isolatedProcrastination, mankind's greatest labour saving device!
Acoustic insulation ARB TPMS 3xARB air compressors After cooler Air tank On-board OCD pressure air/water cleaning Additional 50L fuel Carpet in doors ABE 2x1kg Waeco 28L modified fridge Battery 4x26ah Solar 120w Victron MPPT 100/20 DC-DC 18amps 175amp jumper plug Awning 6x255/60R18
22nd Oct 2022 10:47 pm
Lightwater
Member Since: 21 Aug 2014
Location: Sydney Northern Beaches
Posts: 4906
Now your caravan solar panels. Make sure they are clean.
If you don't have a meter to see how much solar you are getting.
Just sketch on the back of an envelope any angle you want, divide the angled width of the parallel lines by the width of the overhead sun, then multiply by watts.
Or on your smartphone calculator: Panel Watts sin angle = Watts you will get. This example is a 150 watt panel & sun 25° up from the horizon, so the panel produces 63 watts, if it is a clear sky.
Click image to enlarge
The simplest thing would be to get a portable folding panel, then it can be pointed square to the sun.
I would bypass the controller on the back of the panel, they really should be next to the battery. Install a new controller next to the battery. Also use some thicker gauge wire. This is even more critical if you need to extend the cable to reach some sun.
If you have a MPPT controller (I doubt it), then you have to adjust the voltage as one will cause the other to turn off too soon, & it could be the smaller setup controlling the larger setup.
The following text I pasted from another forum. It is about using 2 MPPT controllers. I have 6 x 20 watt Projecta panels so I can do a 40 plus 80 watt test (or 60 + 60 for that matter).
I custom built the setup as they had to fit in a space on the roof when folded.
My Victron 75/10 was at its maximum output of 10 amps with 120 watts of panels under ideal conditions. The MPPT will put out more amps at a lower voltage when the battery is obviously at a lower voltage. Most of the time its output is around 9 amps so the 75/10 is ok.
But under ideal conditions the 75/10 was hitting its 10 amp limit output & I was interested to know how much more I could get. I didn't think it would be much but I was nevertheless interested. 11.3 amps at times, which it really rather academic on many levels as it was under perfect conditions, water cooled & using jump-starting leads between the solar panels & MPPT. But let's say a bit over 10 amps occasionally.
So the next dilemma, as I had already done endless research for 120 watts of solar, a 75/10 should be plenty. At that stage I didn't see myself needing more than 120 watts & still don't. So do I buy a 75/15 which would definitely be enough or to hell with it buy the Victron 100/20 which is much better made with large heatsink.
In the end I decided to buy the Victron 100/20. Very happy with it. Ok, it is overkill but if on the very remote chance I add more solar I have plenty of spare capacity. I didn't want to buy another one unnecessarily. I keep the 75/10 as a spare as it is perfectly adequate for 120 watts.
I have noticed that my Victron 75/10 was just a whisker more efficient, about 1% more than my Victron 100/20. So there is a very slight loss of efficiency. I could wire both in & switch between the two.
You will only need the additional output for when the sun is working hard! In the morning its not going to be as strong so you won't need a higher output for that. In the instruction manual it notes full rated output up to 40°C, so it must derate to its maximum 60°C operating temperature. So if the ambient temperature is very high & it's running at full output, a bit more headroom is probably worth considering. But this is probably more a midday or afternoon issue & by then your battery is probably charged.
75/10 from my experience is enough for your 110 watts.
75/15 provides headroom & will be more than enough if you add another solar panel in less than ideal conditions or for high ambient temperature.
100/20 is just nicely made with large heatsink, with headroom & additional solar capacity in really extreme ambient conditions.
I have gone completely overboard with adding additional heatsinks, but why not. Even thought of adding a really efficient Noctua 0.6 watt fan (I have a spare) but it's not with the 0.6 watt load.
Click image to enlarge
100/20 with even more heatsinks, the cover got warm as well. The 75/10 on the boot floor being tested with a solar 80 watt 40 watt split using 2 controllers. 2 controllers work, but without fine adjustment the smaller controller was dictating the charging & was switching off the 100/20. So one would need to adjust the settings so the larger controller was running things.
I do find the Bluetooth data handy at times. You can also run your load through the Victron MPPT so you you have complete input & output data. So the 100/20 might be more handy with a 20 amp load when fridge is running & you switch on a few other things up to 20 amps maximum load.
Some general photos:
Some Victron MPPT bluebooth data.
Click image to enlarge
On a perfect day I get about 125 watts. With water cooling up to 136 watts.
Click image to enlarge
7.5 amps with 6 panels in parallel, I normally have 2 in series.
Click image to enlarge
Cable looped through the clamp meter 4 times to get more accurate reading, so 16.7/4 = 4.175 amps 2 panels in series x 3, with water cooling (you can squeeze blood out of a stone if you have a well set up system).
Click image to enlarge
Procrastination, mankind's greatest labour saving device!
Acoustic insulation ARB TPMS 3xARB air compressors After cooler Air tank On-board OCD pressure air/water cleaning Additional 50L fuel Carpet in doors ABE 2x1kg Waeco 28L modified fridge Battery 4x26ah Solar 120w Victron MPPT 100/20 DC-DC 18amps 175amp jumper plug Awning 6x255/60R18
23rd Oct 2022 12:24 am
Simon J
Member Since: 27 Jul 2019
Location: Norn Iron
Posts: 703
Lightwater wrote:
I have a Victron 12/12-9 amp.
According to Victron, this is not a battery charger.
Click image to enlarge
23rd Oct 2022 5:29 am
Lightwater
Member Since: 21 Aug 2014
Location: Sydney Northern Beaches
Posts: 4906
In the instruction which came with mine there is no mention of not for batteries. I do agree it is no ideal for batteries as it has a fixed voltage output, but manually adjustable.
I have set both of mine to 13.89 volts as a compromise for gel batteries. So you will need a multimeter & adjust it to the desired voltage while charging.
Since I bought mine. Victron brought out the smart range which would be the one to get. I was also thinking of buying one of these. But to date have been happy with the dumb model which was all that was available at the time.
The dumb 9amp model will be ok for your situation. Because I have a DC clamp meter I am regularly measuring things. When my 4 x 26AH batteries need charging my 2 DC-DC chargers are supplying about 12 amps. When charged, about 3 amps, so basically a trickle charger. A lead acid battery will cope with this & simply charge at less amps. A lithium battery it would be a disaster. Do no do it under any circumstances.
The other option is to get a 12-24 volt DC-DC model & run it into a MPPT controller as they have brilliant charging profiles.Procrastination, mankind's greatest labour saving device!
Acoustic insulation ARB TPMS 3xARB air compressors After cooler Air tank On-board OCD pressure air/water cleaning Additional 50L fuel Carpet in doors ABE 2x1kg Waeco 28L modified fridge Battery 4x26ah Solar 120w Victron MPPT 100/20 DC-DC 18amps 175amp jumper plug Awning 6x255/60R18
23rd Oct 2022 8:07 am
Nodge68
Member Since: 15 Jul 2020
Location: Newquay
Posts: 2082
Automotive power sockets (similar to old cigarette lighters are rated at 10 Amp maximum, and at that current are only suitable for intermittent use.
If you want a secure 10 Amp or more, then you'll need to use a connector which is designed to it. Hyundai Ioniq 5 Ultimate. The family car.
2009 Rimini Red SE TD4. Gone.
2006 Tonga Green i6 HSE. Gone.
Audi A5 convertible, my daily driver.
1972 Hillman Avenger GT, the project.
23rd Oct 2022 8:58 am
Simon J
Member Since: 27 Jul 2019
Location: Norn Iron
Posts: 703
One way round the limited capacity of even the towing power circuits is to use them both at the same time. This battery to battery charger from Sterling - https://sterling-power.com/collections/bat...er-caravan - does this (including using both earth circuits) and so can apparently draw 25A from the tow vehicle.
23rd Oct 2022 4:47 pm
b0ch3n
Member Since: 13 Feb 2022
Location: Wrocław
Posts: 19
In all my cars I've installed Weipu plugs instead of cigarette lighters: https://www.weipuconnector.com/circular-connector-d/sp1311-s
You can get them in all kinds of pin amount/sizes and they can easily take a 6mm2 wires (for a fridge, for example).
They are also threaded so won't disconnect without your will to do so
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22nd Oct 2022 10:47 pm
