Re: Another happy Chinook owner
Posted: June 25th, 2018, 4:54 pm
LOL on the carpet piece. I hear you! There's nothing I hate more than yanking on some potentially fragile part before I know if that's really how it's supposed to come off. 
Well at least your generator wire is 6' shorter than on my era. Mine started on the passenger side at the battery, crossed over to the driver's side under the hood, then down to the driver's side frame rail, then down the driver's side frame rail to near the rear axle, then BACK across to the driver's side to the generator. With another ten feet of wire they could have gone 'round the world
Cool that you are an electrician! Talk about convenient
Voltage drop is such a huge factor in 12 volt systems, and you already have a handle on it. Not sure how it's done on your vintage, but another biggie on 1997+ is the wire from the charger (brown box) to the house batts. It's an 8AWG wire that goes from the brown box (in the kitchen ell) back to the outside wall along the shower stall, then up to the top of the long window, along the window top forward and to the top of the "pillar" behind the driver's seat, then down the pillar and through the floor, then over to the battery compartment (under the water heater). That's like 30' of wire. Oh, and in case that wasn't enough, it also handles all the house loads in other direction. Then there is the solar wire that comes down from the passenger roof, through the roof to the overcab and to the controller, across the overcab, down the pillar... (that's 10 or 12 AWG, I forget which).
But that said, Chinook did a nicer job wiring than a lot of RV's I've seen. All color coded, mostly fused (but not all), and documented reasonably well.
The 85% figure isn't a strict number, but here is the reasoning: The way lead acid batteries charge is that there is a "bulk" stage, which is constant current/rising voltage (in our case it's all the current we can throw at them). The voltage rises from wherever it started (say, 12.5) until it gets to around 14.4. At that point they are like 85% full. In order to get through the next stage ("absorption"), they need constant voltage for a period of hours. Say 14.4 volts for two or three hours. The current then decreases until they are charged (on my Lifeline batteries for example, that should be at about .5 amps per 100 ah). Then they'd like to go into float (13.5 volts or so). The alternator lacks that controlled absorption phase, so it basically does bulk (or float if they are already charged), but can't sustain absorption.
There are "battery to battery" chargers you can get (e.g. Sterling), that condition the alternator power much like a good shore charger or solar controller, but I haven't installed one. 99% of the time my solar setup does the job, so I figured no need to put the extra strain on the alternator. I have a manual combiner switch (vs. the recalled Surepower 1315 automatic one) and just leave it off except for those very few times I need some bulk charging (or to run my "inverter that acts like a generator for those occasional times I need to run a tool or etc."). But that's set up for how I use my Chinook, which would not be everyone's use case.
The three-way refrigerators are completely ridiculous on DC. I want to say they draw something close to 30 amps
I think that's why modern absorption refrigerators are often only two way (110/gas). You can kill a battery right quick on DC with an absorption refrigerator. In contrast, a DC compressor refrigerator/freezer of the same size would draw something like 5 amps DC. But the absorption are efficient on propane, and on 110 most people aren't worried about it.
I'm still laughing at the mental image of you walking out with a piece of carpet in your hand ... and a gaping hole in the floor of the Chinook
Well at least your generator wire is 6' shorter than on my era. Mine started on the passenger side at the battery, crossed over to the driver's side under the hood, then down to the driver's side frame rail, then down the driver's side frame rail to near the rear axle, then BACK across to the driver's side to the generator. With another ten feet of wire they could have gone 'round the world
Cool that you are an electrician! Talk about convenient
Voltage drop is such a huge factor in 12 volt systems, and you already have a handle on it. Not sure how it's done on your vintage, but another biggie on 1997+ is the wire from the charger (brown box) to the house batts. It's an 8AWG wire that goes from the brown box (in the kitchen ell) back to the outside wall along the shower stall, then up to the top of the long window, along the window top forward and to the top of the "pillar" behind the driver's seat, then down the pillar and through the floor, then over to the battery compartment (under the water heater). That's like 30' of wire. Oh, and in case that wasn't enough, it also handles all the house loads in other direction. Then there is the solar wire that comes down from the passenger roof, through the roof to the overcab and to the controller, across the overcab, down the pillar... (that's 10 or 12 AWG, I forget which).But that said, Chinook did a nicer job wiring than a lot of RV's I've seen. All color coded, mostly fused (but not all), and documented reasonably well.
The 85% figure isn't a strict number, but here is the reasoning: The way lead acid batteries charge is that there is a "bulk" stage, which is constant current/rising voltage (in our case it's all the current we can throw at them). The voltage rises from wherever it started (say, 12.5) until it gets to around 14.4. At that point they are like 85% full. In order to get through the next stage ("absorption"), they need constant voltage for a period of hours. Say 14.4 volts for two or three hours. The current then decreases until they are charged (on my Lifeline batteries for example, that should be at about .5 amps per 100 ah). Then they'd like to go into float (13.5 volts or so). The alternator lacks that controlled absorption phase, so it basically does bulk (or float if they are already charged), but can't sustain absorption.
There are "battery to battery" chargers you can get (e.g. Sterling), that condition the alternator power much like a good shore charger or solar controller, but I haven't installed one. 99% of the time my solar setup does the job, so I figured no need to put the extra strain on the alternator. I have a manual combiner switch (vs. the recalled Surepower 1315 automatic one) and just leave it off except for those very few times I need some bulk charging (or to run my "inverter that acts like a generator for those occasional times I need to run a tool or etc."). But that's set up for how I use my Chinook, which would not be everyone's use case.
The three-way refrigerators are completely ridiculous on DC. I want to say they draw something close to 30 amps
I think that's why modern absorption refrigerators are often only two way (110/gas). You can kill a battery right quick on DC with an absorption refrigerator. In contrast, a DC compressor refrigerator/freezer of the same size would draw something like 5 amps DC. But the absorption are efficient on propane, and on 110 most people aren't worried about it.I'm still laughing at the mental image of you walking out with a piece of carpet in your hand ... and a gaping hole in the floor of the Chinook