inverter cables

[Exwindsurfer]

hi pudsey bear . i haven't bought them yet but i was wondering why renogy give you 2 red 35mm & 2 black 35mm cable in the box & looking at youtube they all run the 2 each to the inverter which makes doubling up the 2 would be 70mm to each terminal instead of 50mm what do you think . cheyenne

I personally think the cables Renogy supply with the inverter are not up to the job.

 

[wildebus]

For me, 35mm2 is too small.
When I had around a metre total length between inverter (Victron Multiplus 12/3000) and Battery Bank, I ended up, after some changes (which will come on to) with the battery interconnect cables (the ones that go +ve to +ve and -ve to -ve within the bank) being 50mm2, and the Tap Off from the battery bank to the Inverter to be 70mm2.
You can see in this photo the difference between what some think of 'thick' cable (16mm2) on the B2B and 12V Fusebox connections and the 70mm2 just running over at the top ....

Mid-Current Fusebox by David, on Flickr

I was originally running 35mm2 and 50mm2 but when I was running the inverter and pulling around 200A for say 10-15 minutes, I found the cable was getting a little warmer than I would have liked. updating to 70mm2 had it back down to decently cool enough.

The sizing gauges can vary depending on what you look at, but there are a few factors to consider and ampacity (current carrying capability) is just one of them. Voltage drop can be very important depending on the device (for an Inverter, it is far more important IMO than when specing up a B2B, for example) and heat (=wasted energy) is a key factor, as is efficiency.
You are not going to kill yourself with the cables getting hot, but it is not something you want in your design.



On the EasyPlus 12/1600 I have now, that came with pre-fitted 35mm2 welding cable and that is borderline for the length I have between Battery Bank and Inverter. (word to the wise. UK & European "Welding Cable" is a major step above the equivalent gauge cable that might come with Chinese sourced/made Inverters such as Renogy. The only deserving place for Chinese inverter cables is in the bin)

Just an extra note: don't be fooled by the Victron names.... the 12/3000 Multiplus has an inverter of 2400W, so not that much greater than the Renogy. the 12/1600 Easyplus inverter is 1350W, and NOT 1600W.

 

[cheyenne]

I run my renogy 2000watt inverter on 35mm cable and have had no prods so far.

hi. are the cables the ones that came with the inverter as they are 35mm 2 red 2 black . cheyenne

 

[Tim120]

What distance are we talking about Tim ?.

It's not for me Jeff, I just thought I'd ask the question.

Just an extra note: don't be fooled by the Victron names.... the 12/3000 Multiplus has an inverter of 2400W, so not that much greater than the Renogy. the 12/1600 Easyplus inverter is 1350W, and NOT 1600W.

I have found that out when looking at inverters, I was assuming the 3000 or 2000 referred to watts which is doesn't.
I will spend the time waiting for the battery to arrive to decide what I need wattage wise from an inverter and go from there.
My initial guess is it will be less than I had originally thought.

 

[Pudsey Bear]

We have a 300w pure sine wave but I only used it twice to charge up the scooter, I may use it again if I ever find the vans slow cooker again, we pared down anything a few years ago as we were just too dependent on inverters, panels and batteries, bare minimum nowadays

 

[wildebus]

It's not for me Jeff, I just thought I'd ask the question.



I have found that out when looking at inverters, I was assuming the 3000 or 2000 referred to watts which is doesn't.

I think it is quite likely only Victron use that naming convention where instead of Watts, they are VAs (Volt-Amps) and around 1.2x the nominal wattage (confusing as when someone quotes Ohms Law at you, they will tell you "Watts = Volts x Amps" (so why the hell is a VA not the same as a Watt, you could legitimately ask!).
Youtube 'Vanlifers' don't help by saying things like "I am installing a Victron 12/3000 Multiplus, which has a 3000W inverter" and their fans hang onto every word as gospel

I will spend the time waiting for the battery to arrive to decide what I need wattage wise from an inverter and go from there.
My initial guess is it will be less than I had originally thought.

My approach would be to get an inverter large enough to run whatever single item you want to use (and a battery bank large enough to power that inverter).
If you go too small, it is frustrating. If you go too big, you waste power as there is an overhead in use, which is bigger, the bigger the inverter is. So for example, a 3000W inverter to power a Laptop will use a lot more power than a 500W inverter to power the same Laptop.

Also worth checking with a plug in power meter (here is one example - https://amzn.to/43ut2fd . There are lots of different ones) how much power something REALLY takes to make sure an inverter you get will be large enough. The label on the device cannot be taken as accurate always. For example, I have a 1350W inverter (the confusingly named 12/1600 Easyplus). I have a Tassimo coffee machine and I thought I would try it in the van out of curiosity. It should work as it is rated at 1300W? Inverter goes into overload though. And when I plugged it into a power meter in the house, it actually pulls 2000W! If I really really wanted to use that coffee machine when away, I would be pretty peed off

 

[Mr and Mrs Tupcox]

We used a cable rated to take 240 amps 35mm

 

[cheyenne]

We used a cable rated to take 240 amps 35mm

hi . what power is your inverter please . cheyenne

 

[Mr and Mrs Tupcox]

hi . what power is your inverter please . cheyenne

3000w.

 

[cheyenne]

hi guys . i have decided to fit 50mm battery to inverter cables after watching this .cheyenne

 

[QFour]

You are better using thick electric welding cables. They have lots of thin wires in them and will happily carry the amps. You are carrying a lot of weight about in the way of batteries for a coffee machine and to warm up the occasional pie

 

[cheyenne]

You are better using thick electric welding cables. They have lots of thin wires in them and will happily carry the amps. You are carrying a lot of weight about in the way of batteries for a coffee machine and to warm up the occasional pie

this is why we have the battery's microwave/electric frying pan/toaster/coffee machine/2 tv's/2 satellite decoders /auto satellite dish /2 electric bike chargers /2 lap top's.
so when we are parked up in Spain for 2 months in the winter paying electric on meter we only get charged 15 euros per month instead of 150 euros that's why we have the battery's & if you look at the youtube above that's what those cables are . cheyenne

 

[wildebus]

It is hard to describe the difference in cables (ignoring the physical size) in words to determine what to look for and what to avoid.

Cables come in various forms - Solid Core (like the flat mains ring cable for example), Multi-core (which is found in household wiring for heavy loads like cookers and showers, for example) and Multi-Strand, which is generally referred to as "Flex" cable (as in 'flexible' of course).
only Flex cable should be used in vehicles. it is that simple.

But not all Flex cable is created equal. Decent heavy DC cable made in the UK and Europe (yes, we DO make cable in the UK!) will be pure copper and nice and flexible. A lot of Far Eastern (primarily Chinese) cable is Multi-strand, but is not copper, but aluminium. This has a significantly lower current carrying capacity (forget using those tables on line!) and you can generally tell by the difference in flexibility compared to a nice bit of british flex cable
UK & EU cable is REALLY floppy.
Chinese Cable feels much stiffer and you can put it into a position and it will stay when let go and not relax and drop down. Here is a cable supplied with an Inverter doing an impersonation of a snake-charmers prop ....

Chinese Inverter Cable by David, on Flickr
You try doing that with a length of pure copper cable....
I don't recall what inverter this came with. The cable was never used and I would have swapped it for a length of copper cabler (and almost certainly one thicker for that matter). THe only reason I keep this is so people can see - or rather feel - the difference.


PS. Also don't judge cable by how thick it is including the insulation (I watched a bit of that video and I think the guy said "look how big this cable it" but all we saw is the outside (the same comment I made about one of my cables actually earlier - I'm just as much to blame ).
You need to see the actual cable to see the thickness. I have some 35mm2 cable and externally it is identical to a piece of 70mm2 cable I have as the insualtion of the 35mm2 cable happens to be really thick. If you just compared them externally, you would think they were the same.
(cheap jump leads are like that - incredibly thick insulation to make you thuink you are getting hefty cables).

 

[Tim120]

I think it is quite likely only Victron use that naming convention where instead of Watts, they are VAs (Volt-Amps) and around 1.2x the nominal wattage (confusing as when someone quotes Ohms Law at you, they will tell you "Watts = Volts x Amps" (so why the hell is a VA not the same as a Watt, you could legitimately ask!).
Youtube 'Vanlifers' don't help by saying things like "I am installing a Victron 12/3000 Multiplus, which has a 3000W inverter" and their fans hang onto every word as gospel


My approach would be to get an inverter large enough to run whatever single item you want to use (and a battery bank large enough to power that inverter).
If you go too small, it is frustrating. If you go too big, you waste power as there is an overhead in use, which is bigger, the bigger the inverter is. So for example, a 3000W inverter to power a Laptop will use a lot more power than a 500W inverter to power the same Laptop.

Also worth checking with a plug in power meter (here is one example - https://amzn.to/43ut2fd . There are lots of different ones) how much power something REALLY takes to make sure an inverter you get will be large enough. The label on the device cannot be taken as accurate always. For example, I have a 1350W inverter (the confusingly named 12/1600 Easyplus). I have a Tassimo coffee machine and I thought I would try it in the van out of curiosity. It should work as it is rated at 1300W? Inverter goes into overload though. And when I plugged it into a power meter in the house, it actually pulls 2000W! If I really really wanted to use that coffee machine when away, I would be pretty peed off

Thanks David, good advice as always. Power meter on order. Will be interesting to see how much power is actually used as opposed to how much is quoted as being used.

 

[Pudsey Bear]

I did wonder why it was termed as IE 10mm2 a sparky told me it was the diameter of the individual strands multiplied by the number of them, so I got a bit of cable and the Vernier out and it pretty much works out that way, as David says the looks tell you nothing and you can buy quality cable in thin wall or thick wall, thin wall tends to be automotive for weight saving.

 

[wildebus]

Thanks David, good advice as always. Power meter on order. Will be interesting to see how much power is actually used as opposed to how much is quoted as being used.

you can get obessive with those meters as well! (well, I can ). If you have an air fryer, you can see just how much power is used to cook a portion of chips say. It is useful info though. If cooking on electric only takes out say 10% of the battery power and you have good solar, why not use it instead of gas

 

[wildebus]

I did wonder why it was termed as IE 10mm2 a sparky told me it was the diameter of the individual strands multiplied by the number of them, so I got a bit of cable and the Vernier out and it pretty much works out that way, as David says the looks tell you nothing and you can buy quality cable in thin wall or thick wall, thin wall tends to be automotive for weight saving.

I sold a cable kit to someone on ebay one time and he sent it back saying the cable was too thick! I think he must have drilled holes 1mm in diameter or something and the cable (just for lighting or USBs or whatever) wouldn't go through it, as he thought the size quoted was the external diameter I suppose?
I switched to thin-wall cabling a few years ago actually. Same supplier and quality but.
Found it a bit nicer to work with - but when you have thin and thick next to each other, the thinwall does appear a lot smaller!

 

[Tim120]

you can get obessive with those meters as well! (well, I can ). If you have an air fryer, you can see just how much power is used to cook a portion of chips say. It is useful info though. If cooking on electric only takes out say 10% of the battery power and you have good solar, why not use it instead of gas

I do have an air fryer, and it will be interesting to see it's useage. I have a vague recolection of the definition of a calorie being the amount of energy required to raise an amount of water by 1 degree C. How this relates to chips I have no idea, however, mass of chips at given temp raised to piping hot uses x amount of energy, that I can understand.
Now, a portion can mean many things to many people and chips is a good example...

 

[Exwindsurfer]

I do have an air fryer, and it will be interesting to see it's useage. I have a vague recolection of the definition of a calorie being the amount of energy required to raise an amount of water by 1 degree C. How this relates to chips I have no idea, however, mass of chips at given temp raised to piping hot uses x amount of energy, that I can understand.
Now, a portion can mean many things to many people and chips is a good example...

ill be trying our airfryer this weekend Tim (as in chips)lolol