Enough battery power?

[tireman9]

I have a friend with a trailer. He is new to RV life. He asked me the following:

"I want to update the  Battery and Electrical system in the camper. I want to be able to run my heater overnight and not damage my batteries.

I have 2) 80 amp h batteries.

I have a standard propane heating unit. 

Can I run one night and not damage the batteries? 

How long will I need to charge it?

Do you have contact the is an expert in this area?  "

 

I told him this

 

1. Check the info plate on the blower or look-up info on the internet.

2. Calculate the Amp Hours you need to run the blower all night plus any other electrical items (lights, refrigerator)

3. I would think that with 160 A-H available you should be OK

4. Don't know how fast you can charge the batteries. but will look up some numbers.

I will post on my FMCA forum and let you know what I learn.  

 

I am working on getting him to join.

 

Anyone here want to add info?

 

 

[wolfe10]

Good through process.

But, if 160 amp-hrs (and that is only with new, completely charged batteries), the most he should use to not materially shorten battery life is 80 amp-hrs (50% discharge).

And that 80 would not be available after the first discharge while dry camping, as it is not economically feasible to run a generator to power a charger to get above about 85% SOC (charge rate tapers off to where fuel to run the generator is a lot more than is reasonable for the few amps it takes to go from 85-100%.

How fast they will charge depends on several factors:

Type of battery-- AGM's have lower internal resistance, so charge faster than wet cell batteries.

We have no idea what amp charger he has and whether it is "smart".  Smart chargers charge at higher voltage (and therefore amps into the battery) in BULK MODE= when batteries are deeply discharged.  "Stupid" chargers/converters charge at the same voltage whether the batteries are fully charged or deeply discharged.

[manholt]

As long as everything he has is 12VDC...I see no problem!  Why does he not want to run his propane furnace? 

I re-read his quote.  A inverter/charger would be my choice, but for that, he would need a small portable generator...all can be done for about $1,000. 

Also, see Brett above..he came in while I was responding!

[thezafts]

If the furnace use of battery power is the main issue, why not use a Big Buddy or a Wave propane heater that does not need any electricity?

Also change all high use lights to LED bulbs.

Then to re charge the batteries, besides generator, there is solar.  All he needs a is panel, say 200 watts about $200, solar charge controller, about $150, and some cables.  In good sun that would re charge the 80ah used in about 8 hours.  He still has the generator for bad days and additional charging.

Use the generator to run any 110 volt appliances.  If he wants to use an inverter for110 volt devices then the solar system will probably need to be increased in size.

[wildebill308]

I would say you shouldn't have a problem. The fan will not run 100% of the time unless it is extremely cold out. Do a test run, see what the charge is after one night.

Bill

[hermanmullins]

Roger,

Several questions.

Is he concerned about when dry camping, on shore power in a campground or both?

Does he have a Converter or an Inverter/charger?

Does he have Deep cell Golf Cart batteries or Cranking Batteries?

Herman

[manholt]

Just curious..pull behind or 5'er, slides, length, used or new?  Ohio is cold in winter, is he heading south?   

[tireman9]

Thanks for all the replies.  He lives in TN and is just looking to the future.

Yes he has a propane furnace so IMO the real power drain is just the blower.  I think a test run and careful measurement of batteries would give the best indicator.