One battery bank

Topic: One battery bank (Read 856 times) previous topic - next topic

One battery bank

August 13, 2015, 07:23:56 pm

I am considering converting my 3 battery bay to one battery bank (house and chassis combined). My reason for doing this is to extend dry camping capability. The other advantage is to simplify the 12V wiring (remove the isolator).

I plan to get a Honda eu2000i super quiet mini-generator as a backup to use in the (hopefully) rare event of running the batteries too low overnight to start the genny. Anyone with pro's and con's to doing this?

Re: One battery bank

Reply #1 – August 13, 2015, 07:30:49 pm

Good idea. I do the same. honda 12 volt output is only 9 amps, so I bought a true 40 amp output, [not starting amps] battery
charger, I plug into the honda for charging the house bank. Do not really need it with the genset, but like a backup plan.

Jim

Re: One battery bank

Reply #2 – August 13, 2015, 07:33:47 pm

I wouldn't. What happens when you run the batteries down somehow and can't start the Detroit? The two banks are made up of two different types of batteries that are chosen for their specific work. The engine batteries are designed to deliver a lot of amps for a brief time (starting the engine), while the house batteries are designed to deliver a lot of amp-hours over a longer period (inverter, lights, fans, etc.). Batteries designed for deep discharge (house batteries) often don't like being used as starting batteries, and starting batteries don't fare well when used as house batteries.

Re: One battery bank

Reply #3 – August 13, 2015, 07:39:46 pm

I run the same type agm for starting and house, combined, probably 5000 starting amps, 5 seconds to start engine is not going to affect them.

Re: One battery bank

Reply #4 – August 13, 2015, 07:41:43 pm

David:

Good points. I am considering replacing all 3 batteries with O-Reilly's 8D AGMs - there has been a lot of good recent discussion on these batteries - they are happy doing starting and deep discharge service. To start the big Detroit (if necessary) I would pull out the handy Honda mini-generator and top off the AGMs (may delay my departure some...

)

Re: One battery bank

Reply #5 – August 13, 2015, 07:49:21 pm

Thats what I have.

Re: One battery bank

Reply #6 – August 13, 2015, 07:54:57 pm

Quote from: jcus – August 13, 2015, 07:30:49 pm

Good idea. I do the same. honda 12 volt output is only 9 amps, so I bought a true 40 amp output, [not starting amps] battery
charger, I plug into the honda for charging the house bank. Do not really need it with the genset, but like a backup plan.

Jim:

Yes, the Honda 12V output is pretty small. My plan is to upgrade my charger/converter to 100 amps, and then use the Honda 120V output to charge at 100 amps. This should get me back in business pretty quickly...

Re: One battery bank

Reply #7 – August 13, 2015, 07:55:37 pm

Peter,

Wyatt (another member) has done this change to his coach several years ago.. The last time we chatted he is very pleased with the system. He can elaborate as to exactly what he has done. Seems like he posted what he has done but don't see it right now. After chatting with him about his set up we are changing to an independent converter and inverter set up also.

Pamela & Mike

Re: One battery bank

Reply #8 – August 13, 2015, 08:02:18 pm

Quote from: Pamela & Mike – August 13, 2015, 07:55:37 pm

Peter,

Wyatt (another member) has done this change to his coach several years ago.. The last time we chatted he is very pleased with the system. He can elaborate as to exactly what he has done. Seems like he posted what he has done but don't see it right now. After chatting with him about his set up we are changing to an independent converter and inverter set up also.

Pamela & Mike:

Yes, was going to upgrade to a charger/inverter combo - but, having them separate gives you a lot more flexibility (you can run them both at the same time to defeat a 20 amp gfci campground outlet). So I recently added a Xantrex 2000 watt sine wave inverter, and plan to upgrade to this for a charger/converter:

WFCO 100 amp Charger/Converter

As an Amazon Associate Foretravel Owners' Forum earns from qualifying purchases.

Re: One battery bank

Reply #9 – August 13, 2015, 08:13:31 pm

Single battery system requires a lot of "due diligence".

A much better, but very closely related idea is to set up the two battery banks on a simple marine ON-OFF switch. On to combine for charging, off to prevent one battery bank from being so deeply discharged that you can't start the engine. And, if you are in the coach and monitoring voltage, indeed discharge on ON (both batteries combined).

So, on once side of the switch, chassis battery and alternator output (B+). On other side, house bank.

Re: One battery bank

Reply #10 – August 13, 2015, 08:22:04 pm

I run a honda EU2000i generator with a propane conversion kit I got online Honda EU2000i Generator Propane & Natural Gas Tri Fuel Conversion Kit

I have a grill output acme connector on my 75 gallon coach propane tank that I hook the generator up to. The eu2000I will run one roof air or major appliance at a time. With one dometic penguin running, I shut off everything else including my battery charger. If I dont need air, itll run my microwave, coffee maker, water heater, all one at a time. itll run the inverter charger with it limited to 10 amps AC input and once batteries are charged, itll run other appliances.

Running it off propane eliminates having to carry gasoline with you. I already have a ridiculous 75 gallons of propane. It would run the honda for two months.

With the honda able to run a 70-80 amp charge converter, you can easily convert your coach to a single battery bank. If you ever need to emergency charge to start an engine, it would only take a few minutes to get a lot of amps into the batteries with the honda. otherwise, youre fine. You can probably dry camp for several days before you get so low the engine wouldnt start. I think this is a great idea.

You can also use a yandina combiner to keep the banks seperate and combine them automatically for charging, and add a switch to combine them for extended dry camping. (like a boost switch, but reliable for continuous use) Combiner 160 Sheet

I am going to replace my charge isolator with a yandina combiner 160. hook the alternator and start batteries to one post and the house bank on the other post. full 100% charge to both banks and isolation as well. much better than a diode based isolator.

Re: One battery bank

Reply #11 – August 13, 2015, 08:27:12 pm

Quote from: car54 – August 13, 2015, 08:22:04 pm

I run a honda EU2000i generator with a propane conversion kit I got online Honda EU2000i Generator Propane & Natural Gas Tri Fuel Conversion Kit

Matt:

Very cool, I was not thrilled with having to carry ANOTHER fuel... Thanks!

Re: One battery bank

Reply #12 – August 13, 2015, 08:46:11 pm

I looked at a bunch of different kits online and this was by far the best one I found. It is compact, mounts in a way that doesnt interfere with gasoline operation or oil changes, and works well. Ive got 200hrs of propane only operation and still havent emptied my 75 gallon tank. and the fridge has been on over two months since the last fill.

Re: One battery bank

Reply #13 – August 13, 2015, 08:58:18 pm

Good idea on the propane conversion kit, also have a combiner in parallel with the normal isolator. Whichever bank is
being charged, will also charge the other bank. No need for trickle start or echocharger for start batteries.

Jim

Re: One battery bank

Reply #14 – August 13, 2015, 10:01:09 pm

Quote from: jcus – August 13, 2015, 07:39:46 pm

I run the same type agm for starting and house, combined, probably 5000 starting amps, 5 seconds to start engine is not going to affect them.

Many deep cycle golf cart type batteries are not designed to put out the amperage that starting batteries do. I've heard stories of the terminals being vaporized because of all the amps during starting.

Why mess with something that is already wired up fine? I removed the diode combiner and installed a yandina combiner. Works perfectly.

Re: One battery bank

Reply #15 – August 13, 2015, 10:28:42 pm

Peter, you might have a hard time charging at 100 amps with a honda 2000 generator. They only put out 1300 watts continuous and burn 1 gallon of gas in just over three hours at full load. And they are much less efficient on LP. You need to use a multistep charger to protect the batteries as well. I like the idea of using a separate inverter and charger. Separate they each seem to be more efficient.

Roger

Re: One battery bank

Reply #16 – August 13, 2015, 10:31:26 pm

Quote from: krush – August 13, 2015, 10:01:09 pm

Many deep cycle golf cart type batteries are not designed to put out the amperage that starting batteries do. I've heard stories of the terminals being vaporized because of all the amps during starting.

Why mess with something that is already wired up fine? I removed the diode combiner and installed a yandina combiner. Works perfectly.

Krush,
We are not talking about golf cart batteries, the o'rilley 8d agm's are rated at 1150 starting amps and built as well as many
high dollar deep cycle batteries. I run can run my all electric coach [except for fridge and ac's] for several days without
recharging and getting below 75%. If the terminals are vaporizing, it is not the battery, it is the terminal or inadequate wiring.
I kept the foretravel isolator for starting and charging both banks when the engine is running, and the combiner, [rated at 75 amps] is just for charging the start batteries when the house batteries are being charged.

Jim

Re: One battery bank

Reply #17 – August 13, 2015, 10:43:04 pm

My honda eu 2000 is rated at 1800 continuous. It will run a roof ac only if a soft start is installed. I depends on the charger, but
ohms law says it should run a 100 amp 12 volt charger, [1200 watts] Trouble is finding one that will output that much. I settled on a 40 amp., which will run for 7 hours on the honda, on one gallon of gas. This will recharge most battery banks.

Re: One battery bank

Reply #18 – August 13, 2015, 10:58:58 pm

Quote from: Roger and Susan in Home2 – August 13, 2015, 10:28:42 pm

Peter, you might have a hard time charging at 100 amps with a honda 2000 generator. They only put out 1300 watts continuous and burn 1 gallon of gas in just over three hours at full load. And they are much less efficient on LP. You need to use a multistep charger to protect the batteries as well. I like the idea of using a separate inverter and charger. Separate they each seem to be more efficient.

Roger

You may need to re evaluate your facts here.

1600w (13.3A) continuous, is the official rating. not 1300. However mine will run one dometic penguin AC continuously for hours at 15amps. It even starts it! (ON LP!)

and much less efficient on LP? Any proof to back this up? Of course LP has less btus than liquid gasoline, but that doesn't really make it "much less efficient". I loadbank tested mine to 2200 watts on lp when adjusting the fuel screw. It held a 2200 watt, 18.4 amp load for 10 minutes without an overload light. Don't know how much propane it is consuming, but as a quiet, vibration free backup generator for "dry" camping with no aircon, just to keep batteries charged, it is amazing. I do NOT camp at campgrounds, and spend several days at a time camped out without hookups. I don't even have a working inverter right now, so I use the honda for everything. keeps hours off the diesel gen, keeps it quiet and no vibration or noise inside from a huge diesel generator running.

Re: One battery bank

Reply #19 – August 13, 2015, 11:30:27 pm

I have five of the O'Reilly AGM8D batteries. Before committing to that route (adding another two battery slide out above the factory installed slide out), I studied the spec sheets and the East Penn technical documents. These batteries actually are rated at 1450 cold cranking amps @ 0º ƒ and 1800 marine cranking amps @ 32º ƒ. I have a single AGM8D (this is O'Reilly's part number for the battery and the only way I have found to pull it up on the lame O'Reilly web site) for the starting battery and it spins the 8.3 ISC Cummins like a top without boost, now that I have the cabling sorted out a bit better. This battery is about 14 months old and doing quite well. Still working out what kind of combining and charging options I want to pursue, but for now I turn the boost switch on for a few hours every few days, often just letting the solar do the charging. I am pretty happy with these batteries, especially for the price.
Don

Quote from: jcus – August 13, 2015, 10:31:26 pm

...the o'rilley 8d agm's are rated at 1150 starting amps and built as well as many
high dollar deep cycle batteries.
Jim

Re: One battery bank

Reply #20 – August 13, 2015, 11:47:25 pm

Don,
You are right,only looked at my house system, I use the mk [republic] 4d's agms which are 1150 starting amps at 0f.
By the way, in full sun, my coach is going from 85% to 100% by noon. Highest voltage so far, early morning, 121.

Jim

Re: One battery bank

Reply #21 – August 13, 2015, 11:54:27 pm

Yup, that is right, 13.3 amps, 1600 watts rated for continuous duty. Typo. If you can push that and have a small generator that lasts, great.

I was trying to point out that even at 1600 watts Peter might not be to run a 100 amp charger. I looked at getting a Honda Gen like these but just didn't want to carry gasoline. It takes a lot more lp to get the same output than gasoline. That makes it a less efficient fuel.

If the Honda Gen fits your use needs great. Some folks like solar. Some like to be where they can plug in. Some have mixed use needs. Your way is not the only way.

Re: One battery bank

Reply #22 – August 14, 2015, 12:04:44 am

i am reluctant to not have a separate battery system in a coach.

Leaving something on and not being able to return to the coach is possible.

Re: One battery bank

Reply #23 – August 14, 2015, 12:12:48 am

Well for me, I like the way my system is set up to be able to isolate or cross connect when ever I want to. My gen. set can charge both at the same time, or just the house batteries. I can cross connect to get time on house batteries(which I dont do), and I can cross connect to start the main engine if need be (it happened once). I like the way mine is designed and built, so I don't plan to fix something that "aint busted". Have a great day ---- Fritz

Re: One battery bank

Reply #24 – August 14, 2015, 12:14:47 am

Bob,
You are right, the honda's are not the answer to all problems. But, if you have the honda, diesel gen set, and perhaps good solar.
you are prepared for most bad situations. I even have a big inverter and battery on my toad, to use as a power source if everything else goes south.

Jim

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