Adding Coach batteries - Page 2

Oneilkeys · 08-25-2016, 10:38 PM

Ford lists the 2016 E-450 stripped chassis as having a 120 amp alternator.

Wrench · 08-25-2016, 10:51 PM

OP has a Challenger which, I believe is on an F53 chassis. According to 2017 Ford Stripped Chassis Commercial | View All Specs | Ford.com the alternator is 175 amps.

oldbird · 08-26-2016, 12:12 AM

Very interesting! I got a residential refrig because when it hit 100° my Dometic could not keep up and my wife is on a strict diet. That was about a month ago so haven't tested it out 'off the grid' yet. I do have 4 batteries and a 200 amp alternator in my truck. Also one of the selling points was less chance of a fire but that is debatable!

jpmihalk · 08-26-2016, 01:22 AM

Quote:

Originally Posted by Chance

Agree -- personal preferences. I would prefer all-electric if not too expensive, so propane fridge would not be my first choice.

I'm curious what brand of fridge you have at 10.1 cf, and if you know how much power it uses. That seems like a good size that may fit in a standard RV fridge space. For us 10 cf would be plenty large.

Ours is a Whirlpool that came installed as standard in our Hurricane. In our previous coach we replaced the Norcold with a Haier 10.2cf that we purchased at Lowes. It was almost an exact fit for the space. We also added a 2000 watt inverter and upgraded to AGM batteries and added solar as well since we dry camp often.

Metalman · 08-26-2016, 01:23 AM

Oldbird,
When your refrigerator had problems in hot weather had you been cooling the inside of the RV? I ask because we haven't had a problem with our gas/120-volt refrigerator in hot weather, but since we have a motor home, we run the AC most of the time when the outside temperature is high.

Chance · 08-26-2016, 02:32 AM

Quote:

Originally Posted by jpmihalk

Ours is a Whirlpool that came installed as standard in our Hurricane. In our previous coach we replaced the Norcold with a Haier 10.2cf that we purchased at Lowes. It was almost an exact fit for the space. We also added a 2000 watt inverter and upgraded to AGM batteries and added solar as well since we dry camp often.

Thanks for information, I appreciate it.

In looking at Energy Guide for various sizes of major brands, it appears smaller refrigerators in your size range typically use just under 1 kW-hr of energy per day, whereas larger refrigerators in the 25+ cubic-foot size range use just above 2 kW-hr per day.

If a unit your size used 1,000 watt-hours per 24 hours on average, it would only require about 50 watts from battery, or about 4 Amps. Larger refrigerators would average around 100 watts, or about 8 Amps.

Some previous reports above suggest these government "Energy Guides" may be too optimistic, although they would explain how a large fridge can run through most of the day on two batteries.

I like that a small fridge should run at least twice as long on same battery capacity.

oldbird · 08-26-2016, 03:24 AM

Quote:

Originally Posted by Metalman

Oldbird,
When your refrigerator had problems in hot weather had you been cooling the inside of the RV? I ask because we haven't had a problem with our gas/120-volt refrigerator in hot weather, but since we have a motor home, we run the AC most of the time when the outside temperature is high.

It was one of those double door Dometic's, can't remember the model number. We had both ac's going full blast, any hotter outside and we would have been getting warm inside. I also bought two small fans and added one at the bottom of the refrig to help move air in and upward. Added another at the top to blow out the heat. Put some extra insulation in also and this all helped but I had to run it on high all day. At night I would turn it down. It was just a hassle so I had CrossRv put in a Samsung. The jury is still out on the new refrig because I keep hearing clicking noises like the compressor doesn't want to start up sometimes. I bought the extra insurance. I have 4 AGM batteries and a 3,000 watt invertor.

jpmihalk · 08-26-2016, 11:19 AM

What I did notice is that Forest River has 21.5cf Samsungs in their Georgetown line of motorhomes. They seem nice but I read about complaints that owners simply couldn't get them to run overnight or for more than 8 hours on battery alone. Looking inside, there is an absolute wealth of space (it is even bigger than my current fridge at home) so it seems like it is almost a waste of space and energy. Even doubling the batteries and adding solar would be a stretch (although I haven't really done the math.)

We are quite happy with our Whirlpool and the setup in our Hurricane. Perfect size and energy budget.

Chance · 08-26-2016, 12:46 PM

Quote:

Originally Posted by jpmihalk

What I did notice is that Forest River has 21.5cf Samsungs in their Georgetown line of motorhomes. They seem nice but I read about complaints that owners simply couldn't get them to run overnight or for more than 8 hours on battery alone. ....cut...

The current Georgetown website shows a nice looking French door stainless fridge as part of a Residential Package, described as:

"Stainless Steel Residential Package: 22.5 cu. ft. 110v Stainless Residential Refrigerator with 2000 Watt Inverter and (4) House Batteries (dedicated), Stainless Steel Microwave and Oven"

I just wonder in what context they mean "dedicated"?

Could it mean that inverter and 4 batteries are dedicated to fridge? If so, do they have other house batteries for rest of motorhome?

oldbird · 08-26-2016, 02:14 PM

Most rigs share the same battery pack.

jpmihalk · 08-26-2016, 02:48 PM

Quote:

Originally Posted by Chance

The current Georgetown website shows a nice looking French door stainless fridge as part of a Residential Package, described as:

"Stainless Steel Residential Package: 22.5 cu. ft. 110v Stainless Residential Refrigerator with 2000 Watt Inverter and (4) House Batteries (dedicated), Stainless Steel Microwave and Oven"

I just wonder in what context they mean "dedicated"?

Could it mean that inverter and 4 batteries are dedicated to fridge? If so, do they have other house batteries for rest of motorhome?

From what I understand, the house batteries power the inverter for the fridge only (they leave one 120V AC outlet open) and all house 12V operations.
There are no entertainment or other AC outlets powered by the inverter. That is what they mean by dedicated.

2014 and earlier Georgetowns only had two coach batteries running the residential fridge - they were where most of the complaints came from. In 2015 FR started using 4 house batteries as a result of customer feedback.

fotofx · 08-26-2016, 03:03 PM

Quote:

Originally Posted by Wrench

Attached is a graph of 120 volt AC power usage of the 11 cubic foot Whirlpool refrigerator that came standard in my Miramar.

I have a 2015 Miramar with the same Whirlpool fridge. I have not tried it yet but do you know how long the fridge will run strictly off the inverter before the auto start on the gen will kick on? In my case we leave power on all the time so the fridge is always cold. No hot start needed.

jpmihalk · 08-26-2016, 03:15 PM

Quote:

Originally Posted by fotofx

I have a 2015 Miramar with the same Whirlpool fridge. I have not tried it yet but do you know how long the fridge will run strictly off the inverter before the auto start on the gen will kick on? In my case we leave power on all the time so the fridge is always cold. No hot start needed.

I would think it depends on what you set the battery voltage cutoff for on the generator auto start. Most people say that a battery should never get run below 50% charge, so that comes out to 12.06V. There are battery charge graphs and tables all over the web.

With that said, your mileage may vary - if you are ONLY using the fridge on the inverter, you should be able to get 10 hours from a fully charged battery set, but that also depends on whatever 12V draw is also being used.

fotofx · 08-26-2016, 03:30 PM

I think mine is set at 11... Hmmm.. May need to raise it a bit.

Wrench · 08-26-2016, 03:42 PM

Quote:

Originally Posted by fotofx

I have a 2015 Miramar with the same Whirlpool fridge. I have not tried it yet but do you know how long the fridge will run strictly off the inverter before the auto start on the gen will kick on? In my case we leave power on all the time so the fridge is always cold. No hot start needed.

Didn't try that. We were trying to run the refrigerator through a 10PM-6AM quiet time so no generator. I, too, think the generator starting voltage setting is where to start for this.

Forest Grump · 08-27-2016, 02:35 AM

My ACE has the standard gas/ electric refrigerator and I just use the propane option. We set it at 3 because at the 4 and 5 settings it freezes. We have seen a lot of out door temperatures in the 104 to 109 range and the refrigerator is 34 to 35 degrees on the 3 setting. So we are happy with it.

Mel556180 · 09-04-2016, 09:41 PM

Quote:

Originally Posted by jpmihalk

...Most people say that a battery should never get run below 50% charge, so that comes out to 12.06V.

That is the conventional rule for regular automotive batteries. However, RV (golf cart) deep cycle batteries are designed for repeated deep discharge and recharge. They have thicker plates and other design specs for RV house battery use. I take the manufacturers' word that going less than 50% is not detrimental for their intended use.

gmc · 09-04-2016, 10:07 PM

Quote:

Originally Posted by Mel556180

That is the conventional rule for regular automotive batteries. However, RV (golf cart) deep cycle batteries are designed for repeated deep discharge and recharge. They have thicker plates and other design specs for RV house battery use. I take the manufacturers' word that going less than 50% is not detrimental for their intended use.

hmmm... can you provide a link to a manufacturers statement saying they RECOMMEND discharging below 50%? below 40%??
I've never seen that...

Yes a deep cycle may take a bit more abuse than a standard battery - but they still recommend (from what I have seen) using 50% discharge as the norm.

Deep cycle batteries are designed for lower draw over a period of time than a standard auto battery - which is focused more on Cold Cranking Amps (CCA) - capacity to start a cold engine... which our coach batteries don't need to regularly do (only if you have to use the EMER START...)
But still for longest life should not be fully discharged on regular basis.

Mel556180 · 09-05-2016, 12:32 AM

I offer this description:
"A deep-cycle battery is a lead-acid battery designed to be regularly deeply discharged using most of its capacity. In contrast, starter batteries (e.g. most automotive batteries) are designed to deliver short, high-current bursts for cranking the engine, thus frequently discharging only a small part of their capacity.

A deep-cycle battery is designed to discharge between 45% and 75% of its capacity, depending on the manufacturer and the construction of the battery. Although these batteries can be cycled down to 20% charge, the best lifespan vs cost method is to keep the average cycle at about 45% discharge.

Of course there are no hard and fast rule, and the less stress the longer anything should last. I'm just not as adverse to discharging house batteries more as that's what they are intended for.

Chance · 09-05-2016, 01:51 AM

Quote:

Originally Posted by gmc

hmmm... can you provide a link to a manufacturers statement saying they RECOMMEND discharging below 50%? below 40%??
I've never seen that...

Yes a deep cycle may take a bit more abuse than a standard battery - but they still recommend (from what I have seen) using 50% discharge as the norm.

Deep cycle batteries are designed for lower draw over a period of time than a standard auto battery - which is focused more on Cold Cranking Amps (CCA) - capacity to start a cold engine... which our coach batteries don't need to regularly do (only if you have to use the EMER START...)
But still for longest life should not be fully discharged on regular basis.

As far as I know there is nothing magical about the 50% often used for estimating. It's just another "rule of thumb" that gives good results, but by no means the only correct answer.

Manufacturers sometimes provide a curve of how many discharge cycles we should expect from a battery, and that depends on how deep the battery is discharged each cycle. The less they are discharged, obviously the more cycles we should get out of the battery, right? But there is more than that to it.

Economics should play a major role. For example, if you discharge down 30% and get 1000 cycles, versus discharging 60% and getting 500 cycles, which is better? You may prefer under certain loads to carry half the battery and replace twice as often. Total battery cost may be about the same -- again, depends on load.

If it would help, I can try to locate and post one of these curves.

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