Furnace blower?

The fact is, I question anyone can tell you how many amps the blower pulls overnight. Far too many variables. To add more batteries may not be the answer, simply due to the fact you have to charge them every day.

In my opinion and experience, adding a Wave3 (or equal) will solve the problem. The Wave3 requires no battery, uses propane only. It can be installed as a portable or permanent. It is a CAT heater, not to be confused with non-CAT heaters.

I realize your original post inquired about batteries/furnace, but the Wave3 lightens the load of both.

Wayne

TC probably 3 to 5 amps. Duty cycle 10% to 50%?

The real trick is to start at 100% charged battery. If you are charging with a generator make sure your converter is charging up in the 14.5 volt range. Otherwise 100w of solar will go a long way.

I have a 2012 Lance 855S camper. The fan for the heater is 2 stage. That means the fan turns slower if the temperature between the setting on the thermostat and the inside of the camper are within 3 degrees, the fan will be on low speed and draw just under 5amps. Call it 4.6amps on low speed. If the camper interior is cooler than 3 degrees from the thermostat setting, then the fan will turn to high speed and draw 7 amps. Soon as the room gets to within 3 degrees of thermostat setting, the fan kicks down to low speed. Also, once the room is up to temp, the heater burner turns off, but the fan continues to run for about a minute or two to scavenge the residual heat off the exchanger. On nights below freezing, say around 25 degrees for the low, my camper will cycle the heater, set at 63 degrees, at a rate of 15 minutes on and 15 minutes off, approx. That means, from just after sunset, until sunrise, about 14 hours total, the fan on the heater will run as much as 7 hours drawing 4.6amps. That's a total of 65 amp hours. I have 100 amp hours of battery, so that just about does in a my battery over night. I have solar to recharge my batteries during the day. They charge about 2.5 amps per hour for the daylight hours; about 8 hours in the winter, for a total of maybe 20ah of charging. That leaves me with a deficit of 45ah I need to make up. To do that, I run my generator so the AC charger on board the camper can recharge the batteries. This charger is a 45ah charger, it takes about 2 hours or so to top off the batteries. I try to run the genny for an hour in the morning, then an hour in the evening to top them off and ready for the night.

BTW, I used a chart recorder from work to log the run times and amp draw for the load on the batteries during the night to get my figures, and again while charging during the day.

skipro3 wrote:
I have a 2012 Lance 855S camper. The fan for the heater is 2 stage. That means the fan turns slower if the temperature between the setting on the thermostat and the inside of the camper are within 3 degrees, the fan will be on low speed and draw just under 5amps. Call it 4.6amps on low speed. If the camper interior is cooler than 3 degrees from the thermostat setting, then the fan will turn to high speed and draw 7 amps. Soon as the room gets to within 3 degrees of thermostat setting, the fan kicks down to low speed. Also, once the room is up to temp, the heater burner turns off, but the fan continues to run for about a minute or two to scavenge the residual heat off the exchanger. On nights below freezing, say around 25 degrees for the low, my camper will cycle the heater, set at 63 degrees, at a rate of 15 minutes on and 15 minutes off, approx. That means, from just after sunset, until sunrise, about 14 hours total, the fan on the heater will run as much as 7 hours drawing 4.6amps. That's a total of 65 amp hours. I have 100 amp hours of battery, so that just about does in a my battery over night. I have solar to recharge my batteries during the day. They charge about 2.5 amps per hour for the daylight hours; about 8 hours in the winter, for a total of maybe 20ah of charging. That leaves me with a deficit of 45ah I need to make up. To do that, I run my generator so the AC charger on board the camper can recharge the batteries. This charger is a 45ah charger, it takes about 2 hours or so to top off the batteries. I try to run the genny for an hour in the morning, then an hour in the evening to top them off and ready for the night.

BTW, I used a chart recorder from work to log the run times and amp draw for the load on the batteries during the night to get my figures, and again while charging during the day.

Excellent data skipro...thanx.

This is why a single battery will not cut it for winter camper...unless you have 1 really big battery!

Bill

You are welcome Bill. Most RV batteries are around 100ah at 20 hour drain rate. 2 batteries will double the length of time allowed to stay out without recharging.

I have upgraded my batteries to Interstate 6 volt deep cycle (2 batteries of course) rated at 235ah over a 20 hour drain. This should allow me at least 2 days of winter camping without needing to charge with my genny. Rarely do I stay in one camp spot more than 2 days, so the running of the truck will recharge the batteries.

I chose 6 volt batteries for the specific reason that, with half the number of cells in the same foot print of a 12 volt battery, the plates in the battery are thicker and there fore stronger and will hold up to the rigors of rough roads better. The trade off is, if one battery goes bad, I'm out of the game. Whereas if a dual 12 volt battery system has a bad battery, there is still the reserve of the single battery to handle the job until replacement can take place. Because of that, I installed a switch to jump the truck's 2 batteries to the camper's breaker panel. I can use the truck batteries in a pinch. I installed an automatic disconnect that will shed the camper load if the truck batteries start to get pulled down too far to start the truck. It's called a battery buddy. If voltage drops below a preset level, it trips and isolates the truck battery from the camper breaker panel. I leave it tripped all the time, and will set it if and when I need the emergency power of the truck's batteries.

Reddog1,
We would love to install a wav3 just as we would like to have a second bat ,but no room for either. I know Jerry101 told of how the previous owner added bats in the outside box opposite the gen,but again that would really throw our COG way off making our Lance out of kilter! So it appears we're stuck sleeping in a cool Lance rather than a warm one. O well we have short winter in Florida
Happy Traveling

Of course, if you have electric hookups, you can also use a small electric heater like this Boat Cabin Heater. I find ours very good with more adjustments (down to 600 watts) than the typical small electric heater. We set it on the kitchen counter and point toward the bed area.

skipro3 wrote:
You are welcome Bill. Most RV batteries are around 100ah at 20 hour drain rate. 2 batteries will double the length of time allowed to stay out without recharging.

I have upgraded my batteries to Interstate 6 volt deep cycle (2 batteries of course) rated at 235ah over a 20 hour drain. This should allow me at least 2 days of winter camping without needing to charge with my genny. Rarely do I stay in one camp spot more than 2 days, so the running of the truck will recharge the batteries.

I chose 6 volt batteries for the specific reason that, with half the number of cells in the same foot print of a 12 volt battery, the plates in the battery are thicker and there fore stronger and will hold up to the rigors of rough roads better. The trade off is, if one battery goes bad, I'm out of the game. Whereas if a dual 12 volt battery system has a bad battery, there is still the reserve of the single battery to handle the job until replacement can take place. Because of that, I installed a switch to jump the truck's 2 batteries to the camper's breaker panel. I can use the truck batteries in a pinch. I installed an automatic disconnect that will shed the camper load if the truck batteries start to get pulled down too far to start the truck. It's called a battery buddy. If voltage drops below a preset level, it trips and isolates the truck battery from the camper breaker panel. I leave it tripped all the time, and will set it if and when I need the emergency power of the truck's batteries.

Yeah I considered 6v but went with dual Gr 27 AGM's which we are very pleased with. More useable amp hrs than wet cells and I have to say I am VERY surpised how quickly they recharge just off the truck (OEM charge wire). We are fully recharged in 2-3 hrs...easily.
The 2 AGM's give us enough juice for a weekend of ski camping...by day #3 we will need to either run the genny or go for a drive...our typical ski weekend is 2 days on the slopes and then head home anyway...so it all works out.

Thanks again for the data.

Bill

6pac wrote:
As we remember we've used this Lance since 2006 we it was purchased an it's done this only twice recently. That why I'm thinking either a bad bat or one that needs a good charging.
Happy Traveling

When was the last time you checked the water level in the battery? Mine goes through a little bit of water each year, and an annual check seems to do it well. Top with a little distilled water, and that keeps the acid above the lead plates.

Trojan J150 battery, circa 2007, still going strong with overnight furnace draws.

YMMV!
-Eric