Charging Of Camper Trailer Batteries

Cobes,
I went through this only last week when buying new batteries for my Cruiser. I was told you can not mix wet cell and Optimor Batteries ,I am assuming these are much the same as the Oddysee. With this being the case I ended up with 2 x 105aH Calcium batteries for the car and the 130aH wet cell in the camper. (all batteries are deep cycle) It would pay to check this out with a specialist battery supplier.

big john

Sorry the cabling to the trailer batteries is 10 or 12mm and the cabling to the fridge from the traler batteries is 6mm twin wire.

Cheers
Chris.

Chris, My first reaction is try turning off the 3 way fridge when travelling as they draw quite a lot of power. Perhaps consider running it flat chat on gas overnight. It can be worked out mathematically by using the out put of the alternator as a starting and then calculating the power requirements placed on the system. Obviously if you were running driving lights, fridge, air con, DVD player and the vehicle there would be little or nothing left for charging! Good luck and get the calculator going! My 3 way says it draws I think 75 watts. I put an amp meter on the line to it and it read 8.5 amps which is 102 watts - so perhaps overestimate a little too!

This question has been asked before. I think it is quite complex if you want it to be but doesn't need to be.

I run a similar set to what Cobes is talking about and it seems OK. I don't run the fridge on 12v. I chill it at home on 240 then only use gas when I'm stopped.

The battery on my camper was always a little suspect but I now keep it on charge, $50 solar panel plugged in all the time at home. This means that I'm not starting with a dodgy battery and the car really only has to top it up. I had a neighbour who did a similar thing using a standard battery charger for some time prior to leaving on a trip. He never had a problem. He would drain the battery acid when it was some time between trips just refil charge and go.

Lot of work the trickle from the sun seems more acceptable

Good luck
Duncs

Chris,Rotronics have a system wich isolates ,evaluates and charges the batteries as needed,its not cheap but works a treat.
cheers
Joe Baz

The problem is the voltage drop from the vehicle to the trailer battery.
Even a 0.5 volt drop from around 14.0v at the vehicle (most modern vehicles regulate at about this) will greatly reduce the ultimate maximum charge level in the trailer battery. Wet cell batteries need about 14.0v to fully charge. With a 3 way fridge running the voltage drop could easily be more than 1 volt resulting in no charge being added to the battery at all.
Phil

Hi Cobes.

As has be said before, as far as the alternator is concerned, you can't get a litre of milk from the half litre cow. To charge all the batteries, and to over come the problem of current loss be it distance or cable size restriction, you really need a very large output alternator with all the top connectors.

As in my case, I would suggest that you bite the bullet and buy the largest solar panel that you can get and fit it to your camper by whatever means. This way you will at least get a good supply to your in the camper fridge and some supplementation, however small from the car alternator.

Regard

Thanks for all of your comments.
I might change my setup slightly and do the following:
Fully charge my batteries in the trailer before leaving home.
(possibly purchase an Arrid 3 stage 20 amp smart charger)
Does anyone recommend another charger that can be run from a gene?
Just connect the 3 way fridge to my anderson plug while driving and leave the charging of batteries out of the loop.
Just use my solar panels or gene (with 3 stage charger) if my batteries begin to run low after powering the engel and lights for a period of time.

Cheers
Chris

Hi Mark,
Thanks for your suggestion.
I have considered the Arrid Twin charger and after discussing this issue with a supplier he seemed to steer me towards the Arrid 3 stage smart charger.
The reason being that even although it does boost the voltage my alternator may not be able to supply enough amps to charge all batteries and run both the 3 way fridge and Engel as well as all other accessories.
I'm pretty sure that my Alternator is only 80 amps.

Rox,
Does your Arrid charger state that they are generator friendly?
I know you have a 20 amp model but was wondering if the constant output is less?
Where did you buy it from and if you don't mind me asking how much did you pay for it?
The only price that I have been given is $399.00

Cheers
Chris.