Currently lots of topics concerning the House batteries, so I will start out that we do not dry camp at this time.
I recently removed my older D8 house battery from my battery tray and replaced it with two 12volt Odyssey Extreme series batteries, model 31-PC2150 in parallel ( PHCA ( 5 sec ) 2150, CCA - 1150, HCA - 1545, MCA - 1370, nominal capacity, 20hr is 100, and for 10hr is92 and reserve capacity minutes is 205 ). I have attached some other info on this series together with pictures of my install. The reason I am using these batteries is that a very close friend is a main Distributor for Odyssey in this part of Canada and he wants me to see how they perform as house batteries, so I agreed.
I designed the battery frame so that the two batteries will fit on one pull out tray, and wired in parallel, and I have a small solar panel to keep them charged when not using the RV.
Two weekends ago we went to Winthrop, WA for 5 days and covered 400miles round trip, everything was stable on our return.
Geoffh.
Nice job Bro'
Ask Bruce for 2 more and double your storage (battery) for free!!
JohnH
That is for the future because I have the second battery tray available if I go that route.
I am also thinking of removing the 4/0 cables and putting copper buss bars in parallel, I have some 3/4" wide x 1/4" thick copper bar and the battery connections are 3/8" threaded posts so I am not sure if the bar is big enough?
Geoff
The way I look at it is- if the cross section of the bar is equal or more then the cross section of the wire it will be fine (actually better ie solid piece)
JohnH
Odyssey batteries, if not the best one of the best.
Math ahead ...
1/4"x3/4" = 120.97 sq mm.
3/0 wire = 85.01 sq mm
4/0 wire = 107.20 sq mm
3/8 stud = 53.49 sq mm
So if there are 3-3/0 wires connected to the bus bar does it need to be 3/8" x 1" or just a bit bigger? (241.9 almost = 255.03) to push through 3/0 wires worth of amps? You need the same cross section going out.
If I had a distributor friend to get Odysseys from, I am pretty sure that would be the only battery in everything I own. Congrats on making the jump to one of the finest batteries on earth. Not sure if any of us will live long enough to hear back on when these things actually crap out on you.
Roger, thank you for taking the time to work this out for me, I did have my doubts that the bar would be big enough.
It's been said very regularly, this forum has some very special participants.
Geoff
I have 3/0 cables from start batteries to the post and then to the starter, both + and -. I am adding another 4/0 cable from the batteries to the starter and the starter ground to the ground post just to ease the amp throughput. Individual wires from each battery to a bus bar would be good too.
On your house batteries, the bus bar probably doesn't need to be any bigger than the smallest part which is likely the 3/0 cable to the common posts and then to the inverter. It may all be limited by the max amperage draw the inverter is capable of drawing out or the charger pushing in to the batteries. It is probably 3/0 from the boost solenoid to the common post as well, smaller from your alternator to the isolator and then to the boost solenoid but then those wires are shorter.
Battery to battery to post to inverter, both + and - could be upped to 4/0, almost 25% bigger cross section. You won't get any more out of your inverter but efficiency might improve and charging might be a bit better.
Ampacity or amperage capacity of cables depends on size, temperature and proximity to other cables. Bigger never hurts except the pocketbook. I said in an earlier post I got a spool of 4/0 for much less the 3/0 at Amazon because the box it was in was damaged. Lucky. The price per foot goes down quickly when you buy bigger spools. Just buy black, spend the money on a good crimper and lugs and double wall adhesive lined shrink tube. I now have all of the tools and making cables is not so hard.
I am learning a lot about this by doing. Peter Fleming and Alan at Bay Marine Supply have been patient helping me learn. What a great community of folks helping each other out with ideas that lead to results.
I'm going to get a price on 3/8" x 1 1/4" copper bar, if I decide to stay with 4/0 cables I am lucky enough to work in a Steel fabrication shop and we buy lots of 3/0 & 4/0 ground wire.
Geoff
Geoff does not have an inverter in that coach.
JohnH
With no inverter (house battery bank) and only the Caterpillar 3116 to turn over (chassis battery bank) you are likely way "over-killing" the wiring.
House bank, your largest draw (in terms of CCA) is starting the generator and the HWH jack pump (both up front). Highest draw (in terms of amp-hrs) is propane furnace fan.
If you have no plans to add an inverter, there ARE some upgrades you can do to address those two items (based on what I did on our 1993 U240).
Brett,
thank you for this observation, I would appreciate feedback on the best changes I can do to make this an efficient system.
My friend has given me these batteries so I would like to maximise their use and be sure something else in the circuit is not compromised. All suggestions are really appreciated.
Geoff
Did this a LONG time ago-- maybe Mike Leary still has the paperwork in the coach and can fill in my memory gaps.
With no inverter/high amp loads, and given that the right rear of the U240 is the heavy corner, moved one of the house batteries up to the right front (lightest corner), forward of the wheel. Used the OE heavy wire to HWH jack to the new battery location. Then a very short run from the front battery to the HWH pump and also generator for low voltage drop to both these high amp draws.
Then to avoid the voltage drop through the LONG run from OE house battery to propane furnace, fused and ran the furnace from the positive lug of the generator.
Better for weight distribution and FAR less voltage drop than OE.
Note: this would not work with an inverter, as you would want all batteries close to the inverter.
Brett,
Now you are really giving me things to contemplate , these batteries weigh 80lb each so it would make some difference.
Geoff
An interesting and different set of issues without an inverter. Here is an interesting wire size selection chart. Short and bigger wires means less voltage drop.
Thanks Roger,
I will be checking this out and I am also getting best pricing on cable crimpers, as everyone says.............. there is always a new project!
Geoffh
If wire is exposed, I really like marine pre-tinned wire-- Ancor is one brand. West Marine and other carry it. Expensive but holds up very well. And most West Marine stores also allow you to use their professional quality crimper tool.
For main feeds, I use the 3% drop tables to determine wire gauge.
Ancor makes duplex tinned wire, two wires in a sheath like Romex, in sizes up to 10ga. Maybe bigger. Makes for a tidy installation and easier snaking through tight spaces.
Yes, Ancor makes about any gauge wire you could want:
West Marine (http://www.westmarine.com/search/battery-cable/_/N-1z13gv8?Ntt=ancor+wire)
What I have to do now is check all cable runs from the + side of my batteries( memory thinks there are 4 cables of 2/0 size wire, I park my RV away from my home so it will be the weekend before I can check ) and trace where they go to and upgrade to 3/0?
The - side is 4/0 I think.
Geoffh
Check Bay Marine Supply for an FTZ crimper and lugs.