Monday, Feb 07, 2005 at 13:52
Hi Bluesman,
I went through a similar question recently. There is a lot of info here - just do some searches. Have a look on PostID: 19933 for my comments on a similar question recently.
For me I decided not to charge from the car alternator as I had plenty of battery capacity in the trailer for what I do, & I don't have an isolator fitted. Instead I mounted 4 x 80Ah batteries in 2 banks connected via a marine battery switch (ie off bank 1, both banks, bank 2 about $30 at Witworths) & bought a charger that provides a float voltage (about $80 delivered). This means that when the camper is in storage, all the batteries are always on charge (via the both bank position of the switch) & therefore fully charged when I head out.
I suggest that you start at the basics eg:
- define your budget - "minimal cost" means different things to different peple
- do your research,
- think about how, where & how frequently you will use it.
- remember that high capacity deep cycle batteries are expensive, like any battery need some TLC & can cost more than the rest of the system (I managed to pick up
mine at the right price) ;-)
- calculate your Ah draw & determine how long it will be before you will need to recharge. I have a spreadsheet that helps this heaps - I think I picked it up off the campertrailers.org yahoo groups page. Let me know if you want me to email it to you.
- determine how long you will be away from mains power eg
bush camping vs stopping in c'van parks
- can your existing dual battery setup easily accomodate an additional battery (eg alternator capacity)? This may be a limiting factor.
Once you've done that add any other requirements then design your system. I went through about 3 or 4 designs & costings on paper before actually buying anything.
Clearly defining YOUR requirements greatly assists your ability to build/buy a system that does exactly what YOU want from it.
Other things I'd add are:
- use the biggest cable (sq mm) you can,
- don't rely on the chassis for an earth return (I know lots do, but I consider cable to be cheap compared to the hassle of finding often intermittent faults)
- ensure you use fuses or DC circuit breakers to protect everything.
- you may want to consider making a distribution board in the trailer for your circuits instead of just connecting them via a fuse straight onto the battery. This is what I have done via an Anderson Plug. That way all circuits are individually switched & fused. When I pack up, all electricals get safely stowed & there is no wiring exposed to be inadvertantly damaged.
Let me know if you want to bounce some ideas around or find out a bit more about my setup.
Crozdog
AnswerID:
97092
Follow Up By: David Au - Tuesday, Feb 08, 2005 at 15:35
Tuesday, Feb 08, 2005 at 15:35
CrazyDog '4 x 80Ah batteries' does not make you a hero! LOL
FollowupID:
355876