How Many House Batteries

[Gil_J]

My 99 Country coach as mounting space for up to 8 8D batteries. Currently there are 6 installed and I'm contemplating only putting 4 in when I change them back to AGMs. At over $550 a battery I don't want to needlessly buy more battery capacity than necessary. My last coach was 2008 Beaver Contessa 42. It only had the equivalent of 1 8D and one 2500W inverter. I know my DC loads are a bit more, but I can't imagine they are that much more. We don't do much dry camping, so I can imagine being on battery power for more than over night. During the day we can always recharge them with the generator.

So for all of you that have far more experience with a bus conversion than I, is 4 8D batteries enough?

Thanks,

Gil

[JIM KELLER]

Gil, Don't do it. The batteries and Inverter/Charger system is the heart of the Bus. Your dash, cooling fans for the Mother Boards, all the switches, courtesy lights, outlets, refrig, exhaust fans in the bathroom, etc run on the House Batteries. We have the same side isle Bus and I would keep six of those bad boys on board.

[JIM CHALOUPKA]

We get by with four 8D as do all Libertys I know of.

JIM

[garyde]

Its about hours and load. So, if you can accurately determine wattage /amperages on your batterries and for what amount of time used, you can determine the draw down. Keeping in mind your batteries stop being fully charged at 12.2 volts. So, as you go down below 12.2 volts your re charging which decreases the life of your batteries.
Liberty allows draw down to 11.5 volts before the watch dog program will start the generator for recharge.
Depending on the type of battery you purchase, there is a qty of recycles

.http://www.batteryweb.com/pdf/inverter_battery_sizing_faq.pdf

http://www.lifelinebatteries.com/rvsizing.php

[Reagan Sirmons]

Gil, As I stated in my previous email that the new batteries are the heart of the system, have to be balanced, etc.... If you start out short changing the system, you will have additional difficulties, from my view. Remember that once you ever run these down, they lose enormous capabilities to fully carry the original charges intended. This coach has enormous demands made upon the system. It was not designed for 4 batteries, from my view. I would call Eddie Bralee at National Indoor RV in Lewisville, Tx and ask him his opinion. They are the group that left Buddy Gregg and started their own multi million dollar set up which is one of the best I have seen. If the Buddy Gregg name does not mean anything to you, they were one of the largest Prevost Country Coach dealers in the US if not the largest.
Pres

[Coach Pro LLC]

I would concur with everyone here. The amount of batteries really has more to do with capacity than anything else. Imagine a gallon of water vs. a quart of water. The water remains the same, but you get more "drinks" from the gallon.

Dollar for dollar I would put back in what the system was originally designed to accommodate. The good folks at Country Coach spent a lot of brain power and practical experience calculating loads and and battery capacities. I think the move to AGMs is a good choice, but I would repeat the bank capacity battery for battery.

Either way, it is very important to increase, or decrease, the number of batteries in pairs so that the total is always an even number. I believe CC has a series / parallel house system. This can be cabled for an odd number of batteries but it is not worth the extra effort and wiring these banks can be confusing enough as it is.

Best of luck and safe travels,

Pat Sprenger
Coach Pro LLC

[charlesebrownjr]

Gil, my 99 CC came with 6 8D AGM's as most did. I just replaced mine and added two Moore to make it 8. At the same time we replaced all the cabling with 2/0 copper welding cable, not regular electrical cable. The welding cable will carry more amperage with less heat build up than regular electrical cable. If you need more expert advise you can contact Nick Hessler at Omnitech 541-954-2452. Nick was one of the CC electrical engineers who designed a lot of their systems.

[Gil_J]

Charles you must do a lot of boondocking to need 8 batteries. My cables look like welding cables, but have not taken one out far enough to actually check.

I'm having me 6 wet cells replaced with 6 AGM batteries next week. I find it strange that CC chose to wire all 6 batteries as a single battery bank, at least that's what their wiring diagram shows. Although it will provide for equal discharge across all batteries (or relatively so), it does not provide for equal charging.

Thanks all,

[Gil_J]

6 new AGM batteries installed. Unlike the original wiring I had Coach Worx wire each battery individually to positive and negative buss bars. Although a bit more costly, it's the right way to wire multi-battery banks. It provides a more effective method of equally charging each battery and allows for easy battery isolation. Finally, it gets rid of stacked connections on the batteries, except for the one terminal that has the two temperature sensors on it.

[JIM KELLER]

Gil, Very Interesting. I never thought of that. Hope I get to see this sometime. I have noticed that the way mine is wired the batteries do not receive the same equal voltage from the chargers.

[Gil_J]

Jim I should have called you. We spent last night in Busnell visiting with my parents on our way out of FL. Today we are at Prevost-Jacksonville.

Our trip to AK has begun :-)

[JIM KELLER]

Jim I should have called you. We spent last night in Busnell visiting with my parents on our way out of FL. Today we are at Prevost-Jacksonville.

Our trip to AK has begun :-)

You were close. Good luck on your voyage. Let us know if you need any help. I remember Dale and I talked about the fact that our Buses [ your Bus now ] were just a couple of numbers apart. Both are side isles and the same year. Drive safe and enjoy the Ride !

[wyle.e.kyote]

When we got our coach the electrical system was busticated pretty badly by someones hack job on the batteries and wiring. Originally (we think) it had 8 AGM batteries but someone along its life decided lead acid would be better (or cheaper, or something) they did a bad job wiring and eventually there were problems .. One of the batteries had ruptured(!) [that was a mess to clean up] Anyway .. after about 20 minutes of putting power to the charging system here's what it looked like .. notice all the various heat spots and cold spots the thermal camera picked up on some of the cells? Thats not a good sign. Lots of bad crimps on the wiring and some basic under sized connections in a couple of places. All of it came out and the wiring was rebuilt.

9372

Anyway, we put in AGMs back in and set them up 4 to a side. This is probably overkill but based on my load analysis it will keep the tv's going and the ice cream from melting in the fridge while the kid that got to wear the managers name-tag at the koa looks around for the breaker at night. ;)

[JIM KELLER]

Nice camera image.