Auxiliary power

[rhineholio]

Hi,
I am currently living out of a 2010 Toyota Tundra DC in the Rocky Mountains. I have insulated the bed with cheap bubble wrap insulation, have a lined Leer 100XR topper, and made a bed setup soon to have a chest/full length drawer. I have a bank of 12v power outlets in the sleeping area which I have a cheap duracell power converter plugged into to try and run a heated blanket off of.
The bank of 12v outlets is great but runs off the battery that I need to start the truck.
I am looking into getting a second battery and an isolator. The only thing I'm having trouble with is how to figure out the amp draw and a battery suitable for my situation.
I am planning on running a heated blanket, phone charger, computer, lights, etc. off this power supply.
Last night I tried out a snowmobile battery. Wired in a 12v outlet, plugged the cheap power converter into it, plugged my blanket in and set it to its hottest setting. Some time throughout the night the power converter shut off. I checked the battery this morning and it had plenty of voltage. My conclusion was that it was drawing too many amps and the converter shut off. Is there anyway I can prevent this from happening w/o running the truck?
My overall plan is to make a battery tray, get a marine battery box, and mount everything to the frame using existing holes. I would prefer if the batteries were smaller for obvious reasons.
Is there anyone on here that has a similar set up?
THANK YOU!

 

[colorado matt]

ok I am no expert on electrical stuff ... many here are and I hope they chime in ..... there is also a 12 volt section ..you should try there .... but here is what I do know ..... cheap Duracell power converter is your first problem ..... and battery may have showed voltage but was still weak .... and electric blankets draw a bunch .... maybe more each night than you will be able to put back in the next day by running the engine ... this will result in killing the battery pretty quick..... there are 12 volt blankets but don't know much about them ..... I am thinking that the money you will have to spend and the size and likely amount of batteries needed to pull it off would pay for several very nice comforters or proper sleeping bag .... once tucked in and warm up the bed your good for the night ...... also truck drivers use these ... http://electrowarmth.com/product-category/12-volts-bunk-warmers/?url=12-volt-bunk-warmers .... but again big energy draw but maybe if you just put it on for a few before getting into bed to give that head start ..... little candle stoves might work ... a tent heater that sits outside and works of propane and pumps in hot air .... some other form of heat .... subscribed and will be interested on the responses you get .... good luck ... Matt

 

[dlh62c]

My conclusion was that it was drawing too many amps and the converter shut off.

It could be, but the converter may also have a low voltage shut off.

Trying to power a resistive load such as a heating blanket will run a small battery bank down fast.

Have you considered a small generator to supply power for your electrical needs?

It could power the blanket as well as a small space heater. I heat a small 112 square foot space using this heater run off either an AC outlet or a small generator.

 

[Retired Tanker]

First off, a heated blanket is a huge waste of power. I've slept in a quality sleeping bag to -20f. Sleep as naked as you're comfortable with and put your clothes under the sleeping bag. It take s a little bravery in the morning to emerge and get dressed, but that's part of the adventure.

But, if you insist, create a "power budget" by listing the devices that you want to run and adding up the WATTAGE of each one. If you can't find the wattage, then you'll have to convert the amperage. 1 amp of power at 12 volts will yield 12 watts of potential work. That means your device may be rated for a 1 amp maximum, but the actual consumption will depend on the work being done.

So, lets say your total draw comes to about 375 watts (heated blanket (100 watts), phone charger (1A at 12v = 12 watts), computer (1.5A at 120v = 180 watts), lights (75 watts), etc (???)) of max consumption. At 12 volts, that/s a current draw of 32 amps. An Optima "Yellow" D31T battery has 75 amp-hours, so that's about 2.3 hours of power.

Buy a sleeping bag. Turn the computer off. Use low amp LEDs.

 

[kojackJKU]

I was going to suggest the same. Get a GOOD sleeping bag. Down is great for your application and you can be comfortable and warm down to like -10F. Heated blanket would be ok if you had a generator running all night. your battery will not make it.

 

[AFBronco235]

I also agree that some decent blankets or cold weather sleeping bag would be the simplest, easiest and cheapest option. Not to mention safest.

However, if you're dead set on using a heated blanket, then I suggest you buy a decent house battery (deep cycle), wire it to a solenoid to isolate it from the alternator when not running, and then wirer the solenoid to the "RUN" wire on your ignition switch. This will allow you to run power off your house battery, allow it to be charged from the running engine, yet keep it isolated from the trucks electrical system so using it when the engine is off won't drain your truck's starting battery.

 

[sargeek]

I am with everyone else - get a better sleeping bag or bags or blankets. Once you are settled into you sleeping bags your body should be able to keep you warm throughout the night. I have put mummy bags inside of the bulky rectangle sleeping bag for years when camping - it adds considerable warmth. What you might want to consider is a small 12vdc electric space heater. Your alarm goes off in the am, turn the 12vdc space heater on, and snooze for 15 min. while it heats up the shell so you can get dressed. If you are worried about the power drain, put a remote start on the vehicle. Alarm goes off, hit the remote start, turn the heater on, and snooze for a bit. Get of of the sleeping bags once the chill is out of the air.

Huge waste of energy going from 12vdc to 110vac to run anything.

 

[1Louder]

Better sleeping bag, and maybe a ArkPak or Goal Zero box to run your accessories. I know there are 12 volt electric blankets on Amazon and truck stops but imagine the amp draw is still really high. A propane Mr Heater would like work well even with a green bottle but you would burn through bottles very quickly with regular use.

 

[1stDeuce]

Yeah, to continue to beat this dying horse, you need to do some math... To run a 100W blanket all night and NOT totally discharge the battery will require a LOT of batteries. Not a big battery, several big batteries... The farther you run a battery down, the more you damage it. And the less storage capacity it will have.

With your tiny battery, it's likely you were pulling enough amperage (~32A IIRC) from it that the low voltage shut-down on the inverter tripped a bit early, but that's just due to the battery not being up to the task of supplying so much juice for so long. A bigger battery would obviously do better, but you'd still be dragging it down really low, and you'd probably kill it within a month.

I think the better plan would be a small space heater of some sort to warm the cabin in the morning, and possibly in the evening before you kick off to sleep. Even with the truck running, which doesn't sound like a great idea to me, the little 12v heaters put off barely any heat at all. Certainly not enough to warm your little sleeping cabin. Look for a propane heater. The Mr Buddy variety are ok, as are other catalytic heaters. They use little propane, and produce only a small amount of CO. Still, you might not want to run them all night, just a little in the evening, and a little in the morning. Aside from that a warm sleeping bag, or a warm sleeping companion would be a much more cost effective solution. (Just don't marry her!!)

Finally, even for just generally running/charging things, I would strongly recommend that you invest in a deep cycle battery of some kind, not a standard automotive battery. Regular batteries don't like being discharged deeply and then recharged over and over. They quickly loose their capacity. Even for deep cycles, going below 50% kills them pretty fast. (Measured by resting voltage, 50% is about 12.1v, whereas a fully charged battery should have a resting voltage over 12.7v)

If you do add a second battery, just put it on a relay so that it can charge when you start the truck, but isn't tied to the truck's battery when off. And do realize that it takes HOURS for an alternator to get a battery charged. You might do well to put a ~120w panel on the roof, and only run the truck in the morning for 20 minutes or so to quickly boost charge to a level where solar can top it off over the day. That's for days you aren't driving, of course.

And kudos for living the dream!! I know of one other fella doing the same thing. Unless he is you... But I doubt it, as he's been doing it for years, and I think well past the idea of an electric blanket running off a battery.

 

[IdaSHO]

First off, a heated blanket is a huge waste of power. .

Depends on how you use it.

We have one that remains in the bunk under the covers to keep the bed warm in our camper.

Its only on when the truck is running.


By far one of the best $20 purchases we have ever made.

being greeted to warm blankets when you finally stop for the night is AMAZING ! :ylsmoke:

 

[rhineholio]

ok I am no expert on electrical stuff ... many here are and I hope they chime in ..... there is also a 12 volt section ..you should try there .... but here is what I do know ..... cheap Duracell power converter is your first problem ..... and battery may have showed voltage but was still weak .... and electric blankets draw a bunch .... maybe more each night than you will be able to put back in the next day by running the engine ... this will result in killing the battery pretty quick..... there are 12 volt blankets but don't know much about them ..... I am thinking that the money you will have to spend and the size and likely amount of batteries needed to pull it off would pay for several very nice comforters or proper sleeping bag .... once tucked in and warm up the bed your good for the night ...... also truck drivers use these ... .... but again big energy draw but maybe if you just put it on for a few before getting into bed to give that head start ..... little candle stoves might work ... a tent heater that sits outside and works of propane and pumps in hot air .... some other form of heat .... subscribed and will be interested on the responses you get .... good luck ... Matt

Thanks Matt! I kinda knew the power converter would bite me in the *** but I wanted to see if it would work. Blankets of course. The tea candles and flower pot were used by another one of the guys that used to park at the same place I do now. I may try it but id rather not worry about the potential misshaps. The propane heater im straying away from because I dont want it to be obvious that im sleeping in my truck. Its not really condoned in the county so if it looks like a truck with a topper on it, nobody will ever know. Until I crawl out of it in like Ace Ventura crawling out of that rhino...

It could be, but the converter may also have a low voltage shut off.

Trying to power a resistive load such as a heating blanket will run a small battery bank down fast.

Have you considered a small generator to supply power for your electrical needs?

It could power the blanket as well as a small space heater. I heat a small 112 square foot space using this run off either an AC outlet or a small generator.

I thought about purchasing a small, quiet Honda generator but that might draw some questions when im urban camping somewhere I shouldnt be

First off, a heated blanket is a huge waste of power. I've slept in a quality sleeping bag to -20f. Sleep as naked as you're comfortable with and put your clothes under the sleeping bag. It take s a little bravery in the morning to emerge and get dressed, but that's part of the adventure.
My current set up is; Rei 55*f liner in a Big Agnes Spike lake 14*f down bag, taco'd by a comforter and fleece blanket on top of a ridge rest sleeping pad. My sister and I get various deals on Patagonia gear so I wear a merino wool ninja suit made by airblaster, patagonia synchilla pants, nano puff hoodie, nano pants, and down sweater. My dad gave me these extremely warm/thick wool socks and sometimes I wear a balaclava.
Im more concerned with getting in to change into all that when its -20*f

But, if you insist, create a "power budget" by listing the devices that you want to run and adding up the WATTAGE of each one. If you can't find the wattage, then you'll have to convert the amperage. 1 amp of power at 12 volts will yield 12 watts of potential work. That means your device may be rated for a 1 amp maximum, but the actual consumption will depend on the work being done.

So, lets say your total draw comes to about 375 watts (heated blanket (100 watts), phone charger (1A at 12v = 12 watts), computer (1.5A at 120v = 180 watts), lights (75 watts), etc (???)) of max consumption. At 12 volts, that/s a current draw of 32 amps. An Optima "Yellow" D31T battery has 75 amp-hours, so that's about 2.3 hours of power.

Buy a sleeping bag. Turn the computer off. Use low amp LEDs.

Thank you for the info! This was more a wish list. sometimes its nice to watch a movie before I go to sleep. The lights in the topper are Led and incandescent. Need to run separate power to LED or separate ground (the LED only works when the incandescent is on as well)

Yeah, to continue to beat this dying horse, you need to do some math... To run a 100W blanket all night and NOT totally discharge the battery will require a LOT of batteries. Not a big battery, several big batteries... The farther you run a battery down, the more you damage it. And the less storage capacity it will have.

With your tiny battery, it's likely you were pulling enough amperage (~32A IIRC) from it that the low voltage shut-down on the inverter tripped a bit early, but that's just due to the battery not being up to the task of supplying so much juice for so long. A bigger battery would obviously do better, but you'd still be dragging it down really low, and you'd probably kill it within a month.

I think the better plan would be a small space heater of some sort to warm the cabin in the morning, and possibly in the evening before you kick off to sleep. Even with the truck running, which doesn't sound like a great idea to me, the little 12v heaters put off barely any heat at all. Certainly not enough to warm your little sleeping cabin. Look for a propane heater. The Mr Buddy variety are ok, as are other catalytic heaters. They use little propane, and produce only a small amount of CO. Still, you might not want to run them all night, just a little in the evening, and a little in the morning. Aside from that a warm sleeping bag, or a warm sleeping companion would be a much more cost effective solution. (Just don't marry her!!)

Finally, even for just generally running/charging things, I would strongly recommend that you invest in a deep cycle battery of some kind, not a standard automotive battery. Regular batteries don't like being discharged deeply and then recharged over and over. They quickly loose their capacity. Even for deep cycles, going below 50% kills them pretty fast. (Measured by resting voltage, 50% is about 12.1v, whereas a fully charged battery should have a resting voltage over 12.7v)

If you do add a second battery, just put it on a relay so that it can charge when you start the truck, but isn't tied to the truck's battery when off. And do realize that it takes HOURS for an alternator to get a battery charged. You might do well to put a ~120w panel on the roof, and only run the truck in the morning for 20 minutes or so to quickly boost charge to a level where solar can top it off over the day. That's for days you aren't driving, of course.

And kudos for living the dream!! I know of one other fella doing the same thing. Unless he is you... But I doubt it, as he's been doing it for years, and I think well past the idea of an electric blanket running off a battery.

Thank you! I am most likely going to ditch the idea of the heated blanket. It just seemed like a decent way to make a little heat if i could have made it work cheaply. I would still like to have an auxillary battery and isolator just incase.
When you charge a deep cell battery doesnt it completely discharge it before it charges? That may be for AGM or dry cells though.

Thanks everyone who commented on this thread! Im still open to any comments? suggestions anyone might have.

 

[1stDeuce]

ATM or lead acid batteries do not like to be completely discharged ever. Same with deep cycle versions. The less you discharge them before fully charging, the longer they live.

 

[colorado matt]

Need to run separate power to LED or separate ground (the LED only works when the incandescent is on as well................. my guess is separate ground ... but I am stupid on leds

 

[rhineholio]

Need to run separate power to LED or separate ground (the LED only works when the incandescent is on as well................. my guess is separate ground ... but I am stupid on leds

hahaha Im stupid on electricity in general.

 

[WSS]

If you have wind at night, you could put in a 12v wind turbine (make it portable enough for your needs) and run some dump load resistors to heat the bed of your truck. Put a switch in to kick it off/over to charge your 12v battery/batteries. The link posted for resistors is not safe to use as is, needs a steel box to keep from starting a fire or burning yourself from accidental contact and maybe a 12v fan to push the heat out

http://www.ebay.com/itm/divert-load-12-volt-1200-watts-4-wind-turbine-generator-gene-/371161171421

These are not the only guys in town either, search ebay for wind turbines:

http://stores.ebay.com/Missouri-Wind-and-Solar/Wind-Turbine-Kits-/_i.html?_sop=16&_fsub=4950970011