What charges the 12v battery on my travel trailer?
Scojolene said
12:55 PM Jun 16, 2017
I have a 2014 KZ Sportsmen Classic Travel Trailer and I am assuming that when plugged into an outlet this charges the 12v battery on my trailer? My question is this, does the battery get charged as well when the electrical plug is plugged into my truck and my truck is running? I was just wanting to know or refrigerator purposes being run on the 12v battery while we are on the road headed to our destination.
Thanks,
Scott
Bill and Linda said
03:14 PM Jun 16, 2017
Scojolene wrote:
My question is this, does the battery get charged as well when the electrical plug is plugged into my truck and my truck is running? I was just wanting to know or refrigerator purposes being run on the 12v battery while we are on the road headed to our destination.
Thanks,
Scott
Assuming all the wires are connected properly and the fuse is installed in the truck fuse block to feed the trailer 12 volts, yes, the truck will charge the battery. In general up to about 8 amps per hour - but it depends on a number of factors so don't take that 8 amps as a hard number.
Concerning the refrigerator and 12 volts - Assuming an RV Fridge - the 12 volts for the fridge does no cooling. The 12 volt runs the refrigerator control system, fans on the back heat exchanger (if there are fans) and the lights. Actual cooling is done via LP gas or 120 volts. If the fridge is a residential then naturally the cooling is done from a 120 volt AC inverter and, to some extent, the truck 12 volt charging helps with that power coming from the trailer's battery. However, the truck may or may not totally supply enough charging amps to make up for what a residential fridge is requiring. It depends and the only way to know is to measure the charging rate, etc.
RonC said
08:47 AM Jun 18, 2017
To tag on to Bill's comments regarding the residential rig. The Samsung 18 cu ft is a commonly used Residential unit and it will draw 11 amps on startup surge and settle down to 6 amps when running. I have this refrigerator and two big Lifeline AGM GPL4DL 12 volt (210 amp hour each) batteries and they seem to just about break even when traveling ... meaning the truck's battery charging and the Inverter's consumption are pretty close. FWIW.
Bill and Linda said
12:54 PM Jun 18, 2017
RonC wrote:
To tag on to Bill's comments regarding the residential rig. The Samsung 18 cu ft is a commonly used Residential unit and it will draw 11 amps on startup surge and settle down to 6 amps when running. I have this refrigerator and two big Lifeline AGM GPL4DL 12 volt (210 amp hour each) batteries and they seem to just about break even when traveling ... meaning the truck's battery charging and the Inverter's consumption are pretty close. FWIW.
Ron: Good to know info. Might want comment on the 12 volt amps feeding the inverter as well. That is the more interesting number in this situation don't you think? That would be something like 60 odd 12 volt amps per hour in the running condition if I did the math right? So if those numbers are correct the truck really doesn't make up for all the power in use. Doesn't mean everything won't work OK. But the batteries will be depleted some when arriving at a campsite. If 120 volt power at the site, no big deal. If boondocking, maybe not so much. Depends.
The 60 amps/hour probably isn't every hour. I suspect the Samsung, if memory serves which it sometimes doesn't, will draw considerable less after it reaches the cold set-point and goes into idle mode. Have no idea what that exact amp draw is in the idle mode after reaching set point.
Just trying to clarify for those who maybe in the learning mode.
Bill
RonC said
01:58 PM Jun 18, 2017
"That would be something like 60 odd 12 volt amps per hour in the running condition if I did the math right? So if those numbers are correct the truck really doesn't make up for all the power in use."
True ... but the truck makes the depletion rate much less. I go from full hookup to full hookup so I start with fully topped off batteries and arrive (typical 4-5 hour trip) with slightly depleted batteries. Just using the Inverter voltage readout ... I start with 13.5 volts and typically end up with 12.7 volts. Not very scientific, but gives some insight to what's going on. This is in the heat of the summer when the inside of the 5er can get to 98 degrees, so the refrigerator is in a challenging operational environment. Still keeps everything frozen so that's a good thing.
Bill and Linda said
04:01 PM Jun 18, 2017
RonC wrote:
"That would be something like 60 odd 12 volt amps per hour in the running condition if I did the math right? So if those numbers are correct the truck really doesn't make up for all the power in use."
True ... but the truck makes the depletion rate much less. I go from full hookup to full hookup so I start with fully topped off batteries and arrive (typical 4-5 hour trip) with slightly depleted batteries. Just using the Inverter voltage readout ... I start with 13.5 volts and typically end up with 12.7 volts. Not very scientific, but gives some insight to what's going on. This is in the heat of the summer when the inside of the 5er can get to 98 degrees, so the refrigerator is in a challenging operational environment. Still keeps everything frozen so that's a good thing.
Ron, not saying your arrangement doesn't work well. I was trying to sort of respond to the OP that the should not count on the truck fully replenishing the battery bank if the fridge in question was a residential as opposed to an RV LP/AC fridge. All good.
Bill
RonC said
06:25 PM Jun 18, 2017
Yeah ... not feeling any criticism. Just a good discussion on a subject that the OP wasn't sure about. As you said ... all good.
MAYBE2021 said
05:29 PM Jun 19, 2017
Bill and Linda wrote:
Scojolene wrote:
My question is this, does the battery get charged as well when the electrical plug is plugged into my truck and my truck is running? I was just wanting to know or refrigerator purposes being run on the 12v battery while we are on the road headed to our destination.
Thanks,
Scott
Assuming all the wires are connected properly and the fuse is installed in the truck fuse block to feed the trailer 12 volts, yes, the truck will charge the battery. In general up to about 8 amps per hour - but it depends on a number of factors so don't take that 8 amps as a hard number.
Concerning the refrigerator and 12 volts - Assuming an RV Fridge - the 12 volts for the fridge does no cooling. The 12 volt runs the refrigerator control system, fans on the back heat exchanger (if there are fans) and the lights. Actual cooling is done via LP gas or 120 volts. If the fridge is a residential then naturally the cooling is done from a 120 volt AC inverter and, to some extent, the truck 12 volt charging helps with that power coming from the trailer's battery. However, the truck may or may not totally supply enough charging amps to make up for what a residential fridge is requiring. It depends and the only way to know is to measure the charging rate, etc.
Hey Bill, about the 12VDC running the fridge. I know on my current TT there is no 12VDC input, just 120VAC and propane, but on my pop-up it had a true 3-way fridge; 120VAC, 12VDC, and propane. Whenever I was on the road I ran it on 12VDC, the darn propane flame kept blowing out. Maybe on modern larger RVs the 12VDC input does not cool, but on the smaller units the 12VDC does cool. After re-reading your post maybe that's what you ment by "assuming an RV fridge".
Steve
Bill and Linda said
07:27 AM Jun 20, 2017
MAYBE2021 wrote:
Bill and Linda wrote:
Assuming all the wires are connected properly and the fuse is installed in the truck fuse block to feed the trailer 12 volts, yes, the truck will charge the battery. In general up to about 8 amps per hour - but it depends on a number of factors so don't take that 8 amps as a hard number.
Concerning the refrigerator and 12 volts - Assuming an RV Fridge - the 12 volts for the fridge does no cooling. The 12 volt runs the refrigerator control system, fans on the back heat exchanger (if there are fans) and the lights. Actual cooling is done via LP gas or 120 volts. If the fridge is a residential then naturally the cooling is done from a 120 volt AC inverter and, to some extent, the truck 12 volt charging helps with that power coming from the trailer's battery. However, the truck may or may not totally supply enough charging amps to make up for what a residential fridge is requiring. It depends and the only way to know is to measure the charging rate, etc.
Hey Bill, about the 12VDC running the fridge. I know on my current TT there is no 12VDC input, just 120VAC and propane, but on my pop-up it had a true 3-way fridge; 120VAC, 12VDC, and propane. Whenever I was on the road I ran it on 12VDC, the darn propane flame kept blowing out. Maybe on modern larger RVs the 12VDC input does not cool, but on the smaller units the 12VDC does cool. After re-reading your post maybe that's what you ment by "assuming an RV fridge".
Steve
Steve, we're kinda getting down in some old weeds, but here goes. Yes, some LP / 120 volt fridges do not use 12 volts, they sort of make there own via a thermocouple. It isn't much but it is enough to run the LP control system. That's why one had to hold in a button to light the pilot light for LP - till the therocouple warmed up enough to generate enough voltage / current to keep the main burner lit. And yes, there were 12 volt cooling fridges including LP and 120 volt.
What was meant by "RV Fridge" was a generic term used to indicate an LP / 120 volt unit. Those and a 100% residential fridge are the most common now among those who frequent this full-timers or part-time-full time - forum. Many newcomers to the forum are not familiar with the the details of how an LP / 120 volt fridge works. The fact that without 12 volts, in most modern, larger RVs basically nothing will work is a bit of a surprise to them. In many cases without 12 volts the air-conditioning won't work. It depends. So when I answer I try to cover the basis for most readers without getting too far down in the weeds to confuse but still give enough information to be useful. I do my best.
As a comment about the flame blowing out when on the road, sometimes that is / was caused by poor baffling around the fridge. Seen that a long time ago.
BTW, as an aside, most RV type LP ovens still use a thermocouple to keep the pilot lit. Same deal as the older LP refrigerators. So this really old technology hasn't gone entirely away in the RV world. If the unit has a pilot light chances are it has a termocouple in the path of the pilot flame. If the pilot flame goes out for whatever reason the lack of heat on the thermocouple will cause the LP gas safety control valve to close and shut off the gas. Probably more then you or anyone wanted to know. But this also could explain why your fridge wouldn't stay lit while running down the road.
I have a 2014 KZ Sportsmen Classic Travel Trailer and I am assuming that when plugged into an outlet this charges the 12v battery on my trailer? My question is this, does the battery get charged as well when the electrical plug is plugged into my truck and my truck is running? I was just wanting to know or refrigerator purposes being run on the 12v battery while we are on the road headed to our destination.
Thanks,
Scott
Assuming all the wires are connected properly and the fuse is installed in the truck fuse block to feed the trailer 12 volts, yes, the truck will charge the battery. In general up to about 8 amps per hour - but it depends on a number of factors so don't take that 8 amps as a hard number.
Concerning the refrigerator and 12 volts - Assuming an RV Fridge - the 12 volts for the fridge does no cooling. The 12 volt runs the refrigerator control system, fans on the back heat exchanger (if there are fans) and the lights. Actual cooling is done via LP gas or 120 volts. If the fridge is a residential then naturally the cooling is done from a 120 volt AC inverter and, to some extent, the truck 12 volt charging helps with that power coming from the trailer's battery. However, the truck may or may not totally supply enough charging amps to make up for what a residential fridge is requiring. It depends and the only way to know is to measure the charging rate, etc.
Ron: Good to know info. Might want comment on the 12 volt amps feeding the inverter as well. That is the more interesting number in this situation don't you think? That would be something like 60 odd 12 volt amps per hour in the running condition if I did the math right? So if those numbers are correct the truck really doesn't make up for all the power in use. Doesn't mean everything won't work OK. But the batteries will be depleted some when arriving at a campsite. If 120 volt power at the site, no big deal. If boondocking, maybe not so much. Depends.
The 60 amps/hour probably isn't every hour. I suspect the Samsung, if memory serves which it sometimes doesn't, will draw considerable less after it reaches the cold set-point and goes into idle mode. Have no idea what that exact amp draw is in the idle mode after reaching set point.
Just trying to clarify for those who maybe in the learning mode.
Bill
True ... but the truck makes the depletion rate much less. I go from full hookup to full hookup so I start with fully topped off batteries and arrive (typical 4-5 hour trip) with slightly depleted batteries. Just using the Inverter voltage readout ... I start with 13.5 volts and typically end up with 12.7 volts. Not very scientific, but gives some insight to what's going on. This is in the heat of the summer when the inside of the 5er can get to 98 degrees, so the refrigerator is in a challenging operational environment. Still keeps everything frozen so that's a good thing.
Ron, not saying your arrangement doesn't work well. I was trying to sort of respond to the OP that the should not count on the truck fully replenishing the battery bank if the fridge in question was a residential as opposed to an RV LP/AC fridge. All good.
Bill
Hey Bill, about the 12VDC running the fridge. I know on my current TT there is no 12VDC input, just 120VAC and propane, but on my pop-up it had a true 3-way fridge; 120VAC, 12VDC, and propane. Whenever I was on the road I ran it on 12VDC, the darn propane flame kept blowing out. Maybe on modern larger RVs the 12VDC input does not cool, but on the smaller units the 12VDC does cool. After re-reading your post maybe that's what you ment by "assuming an RV fridge".
Steve
Steve, we're kinda getting down in some old weeds, but here goes. Yes, some LP / 120 volt fridges do not use 12 volts, they sort of make there own via a thermocouple. It isn't much but it is enough to run the LP control system. That's why one had to hold in a button to light the pilot light for LP - till the therocouple warmed up enough to generate enough voltage / current to keep the main burner lit. And yes, there were 12 volt cooling fridges including LP and 120 volt.
What was meant by "RV Fridge" was a generic term used to indicate an LP / 120 volt unit. Those and a 100% residential fridge are the most common now among those who frequent this full-timers or part-time-full time - forum. Many newcomers to the forum are not familiar with the the details of how an LP / 120 volt fridge works. The fact that without 12 volts, in most modern, larger RVs basically nothing will work is a bit of a surprise to them. In many cases without 12 volts the air-conditioning won't work. It depends. So when I answer I try to cover the basis for most readers without getting too far down in the weeds to confuse but still give enough information to be useful. I do my best.
As a comment about the flame blowing out when on the road, sometimes that is / was caused by poor baffling around the fridge. Seen that a long time ago.
BTW, as an aside, most RV type LP ovens still use a thermocouple to keep the pilot lit. Same deal as the older LP refrigerators. So this really old technology hasn't gone entirely away in the RV world. If the unit has a pilot light chances are it has a termocouple in the path of the pilot flame. If the pilot flame goes out for whatever reason the lack of heat on the thermocouple will cause the LP gas safety control valve to close and shut off the gas. Probably more then you or anyone wanted to know. But this also could explain why your fridge wouldn't stay lit while running down the road.
Bill