Extender Lead for Camper Trailer

[Grizzly_Adams]

G'day all,

One of the "optional accessories" for my camper trailer is a 6m anderson plug extension lead for when you need to plug your camper into the vehicle whilst camping.

Currently my Camper has a Solar panel and a battery, however the battery is a cheap-ar*e maintenance one that only has 450 CCA (not that it would ever be used for cranking, but just for general information). This is because the camper I have is ex-demo and that was what the dealer put on their demo stock - cheap, cruddy battery. However it *is* a working battery so I am loath to change it until I kill it.

The problem stems when I am running the 80ltr fridge for more than a day without being connected to some form of external power. The fridge draws variable amperage from 0.5 to 4.5 AMPS Maximum (direct from manufacturers website) and after about a day and a half the battery in the Camper is dead - and it usually happens at night as the Solar panel seems enough to keep everything happy, but once the sun sets......

Anyways was just wondering if it is worth purchasing a 6m extension lead - I have a SC80 in the vehicle setup for a 3 battery system and it works well..

It would just save me having to reverse the vehicle directly up to the camper in order to connect up overnight to keep the fridge running..

Your thoughts?

[Utemad]

Sounds like a good idea. Sometimes you can't get your vehicle in front of your trailer anyway.

Dependent on cost though I'd probably make my own.

[Blknight.aus]

depending on cost make your own... or invest in a second panel to keep the fridge happy.

[ladas]

Make your own

The cable and anderson plugs from Traxide are

10mm twin cable (45 amp rated) @ $12.00 /m $72.00
Two anderson plugs $12.00

$84.00, plus postage and about 15mins and a bit of solder - jobs done.

[Utemad]

about 15mins and a bit of solder - jobs done.

Unless he has a bigger than average soldering iron or even a mini blow torch then I think crimping would be the go.

[drivesafe]

Hi folks, Grizzly PMed me about the extension lead and I suggested to him to post the question here to get some ideas.

I also offered to make him up a 6m extension lead using 10mm2 twin cable, two Anderson plugs and two Safety Covers for $90 including post, plus I can make the leads longer if required at $10 for each additional metre.

There is another way to charge the camper trailer battery and that is to connect a 12 to 240v inverter to the vehicle’s battery when you come back to the camp site and run an ordinary 240v extension cord to a small battery charger in the camper trailer and let it run all night.

This set up has the advantage that the vehicle battery is charged while you are driving around during the day and then it is used to charge the camper trailer battery at night and it does not matter if the vehicle’s battery is lower than the camper battery as the inverter/battery charger set up raises the voltage going into the camper battery anyway.

Cheers

[Redback]

I've done this on my setup, i also have an elcheapo 75AH battery in my camper and a small solar panel to keep it charged during the day (i don't have a fridge running of it though) and after a few cloudy days the near the end of one of our stays in the bush the water pump was starting to show signs that the battery in the camper was running flat, so that night i hooked up the camper battery to our battery fighter charger and ran it off an inverter from my auxillary battery in the car.

Next morning battery was recharged and i went for an explore to recharge my auxillary battery in the car and all was fine that night:D

I saw Tim (drivesafe) mention this in another post and thought now that's worth trying, so i did.

Oh BTW Tim new smart charger is going great, no probs at all:D

Baz.

[Grizzly_Adams]

Wouldn't the cost of the inverter be more expensive then just getting the cable made up?

[drivesafe]

Wouldn't the cost of the inverter be more expensive then just getting the cable made up?

Yep, but as many people already have either a battery charger and/or an inverter, the cost is not that much, if anything.

On the other hand, if you have a cable running to the rear of your vehicle with an Anderson plug on it, then an extension lead is a simple alternative and the extension lead can be used for other things such as powering a compressor or running accessories like a fridge or lights without having to have to have the vehicle right there to connect directly to the battery.

I have an Anderson plug on a short lead at both the front and rear of my rangy and have a 5m extension lead to run what ever I want.

Cheers.

[drivesafe]

Oh BTW Tim new smart charger is going great, no probs at all:D

Baz.

Good and stage 2 should be ready for testing very shortly.

Cheers.

[PhilipA]

Er, why not just make up a lead with HD 2 core and a trailer plug on one end and socket on the other. The plugs are marked with the correct terminal, and they are child's play to do.
Then you do not have to duplicate the wiring and /or plug.
From your post it seems you use the trailer plugs now "by backing the car up to the van"
Regards Philip A

[DiscoStew]

Anyways was just wondering if it is worth purchasing a 6m extension lead - I have a SC80 in the vehicle setup for a 3 battery system and it works well..



I am booked in to get an SC80 in a couple of weeks and I think you may have answered a question that I emailed to Traxide(DriveSafe) this afternoon about how to keep the trailer battery charged when I set up for a week.

Just a quick question though: I thought the rear socket for the trailer would be a separate circuit than for the aux battery in the car. However your solution seems to rely on power being fed to the rear socket even when the engine is off. Does this mean that the two batteries are actually in parallel when the ignition is off and therefore the battery with the lower charge is recharged from the other until they are equal voltage? And therefore there is a further assumption that the aux battery is always charged more because the vehicle gets driven around during the day? With my very basic knowledge I would think this means the trailer battery would never get fully charged (not that it needs to), it would just meet the vehicle battery halfway approx. Whereas the inverter/charger option could actually fully charge the trailer battery even if at some cost to the aux battery, which is also okay especially if you plan a big drive for the next day.

However as always I wonder if I have missed the point somewhere along the line.

An answer to this may save DriveSafe having to deal with my even more convulated set of questions that I sent him this afternoon, which I am sure he would appreciate.:)

[drivesafe]

Hi Paul, first off, I left a message on your answering service but hopefully I’ll answer your questions here.

The first thing this is that just paralleling two batteries will not get the higher charged battery to charge the lower one till they have equal voltages.

If you parallel two batteries of deferent voltages, they will end up with equal voltages but it will be that of the lowest charged battery. In other words and put crudely, if you have one battery with a 12 volt charge and another with a 12.7 volt charge, after a period of time both batteries will have a 12 volt charge.

The reason for this is that all lead acid batteries require a chemical reaction to occur before the battery will absorb power but the reaction has to have at least 13.8 volts applied to battery before they will actually start to absorb the charge being applied. Any voltage below 13.8 will get the chemical reaction going in the battery, which in itself, will use energy but very little power is actually absorbed.

With the two batteries paralleled, because the low battery has 12 volts and the high battery is applying 12.7 volts to the low battery’s terminals, there will be a chemical reaction taking place in the low charged battery that will simply use up the higher charged battery’s voltage difference with no charge being absorbed by the lower charged battery.

Note, it doesn't matter if the two batteries are different sizes and/or types, the results are the same.

Now Paul, to your set up. As there will be two batteries to supply power to an inverter/charger set up when your arrive back at your camp site after each days drive, you should have plenty of stored power, depending on how low the batteries in the D3 were when you started and how long you drove for.

The biggest advantage for you if you use the inverter/charger set up is that you will be charging two batteries at the same time while you are driving each day, furthermore you won’t need to fully recharge the vehicle’s batteries, just replace the bulk of the charged, this means you will only need to get the batteries back up to about 85% to 90% charged.

This means about a two hour drive should get you enough replaced charge to run your inverter/charger set up each night and keep your trailer battery fairly well charged.

Cheers.

[DiscoStew]

Thanks for the reply. I'll give you a call tomorrow but in case this is of interest to other people I'll pop another question in here.:D

I understand your comments about the inverter and given my critical need to not have the trailer battery get too flat i think the inverter is the way to go. Worst case is I flatten the aux battery but the SC80 would protect the main battery and the SC80 auto-cutoff would prevent damaging the aux battery by not completely flattening it. (For other people's sake, my email to DriveSafe highlighted that I have medical equipment ie CPAP running from the trailer battery so it is a higher priority than normal.) I predict that 99% of the time this would keep all my batteries close to fully charged assuming I do some driving most days, which I do.


There is another way to charge the camper trailer battery and that is to connect a 12 to 240v inverter to the vehicle’s battery when you come back to the camp site.
Cheers

When you say connect to the vehicle battery, do you mean pop the bonnet and clip the cables directly to the battery? Or do you mean use the socket at the rear bumper that you would normally attach the trailer to?

[drivesafe]

When you say connect to the vehicle battery, do you mean pop the bonnet and clip the cables directly to the battery? Or do you mean use the socket at the rear bumper that you would normally attach the trailer to?

Hi Paul, if you have an Anderson plug fitted to the rear of your D3, make up an adapter with another Anderson plug and just connect up the inverter to the rear plug.

Cheers

[DiscoStew]

So even though the Anderson plug at the rear is there for connecting the SC80 to the trailer battery while driving, it can also be used to draw power from the Aux battery to power the inverter?

Do I need to tell Motolek to do anything different or is that a standard configuration?

BTW I have a D2 not a D3 but I assume that is irrelevant to the advice.

[drivesafe]

Do I need to tell Motolek to do anything different or is that a standard configuration?

That’s it, just a standard configuration and you can do anything you like and it's the same for a D2 and D3.

Cheers