OK. How Crazy of an Idea is This...

[mblaney]

I would spend the money on fixing your air intrusion, new GP's and, if you are really serious, use an upgraded GP relay (see my signature). Total cost for all of this is probably $200. A lot more effective than any other work-around. Mine fires right up with no block heater after 12 hours at -20 C (-4 F).

 

[madpogue]

How about some charcoal briquettes in an old cooking pot.

At lunch time, light them up, place under engine with a vertical shroud for wind protection. At 5pm, remove, douse with water/snow, put lid onto pot, crank warm engine and go.

Or one of those old picnic grills from the '80s; they sit pretty flat.

Why not use an actual 12v heater pad on the oil pan or 12v immersion heater? They're readily available on Amazon. You'd do away with the conversion losses. Run a battery isolator and your charging system can top up the aux batteries, and still draw from them for a reserve start capacity.

Still no free lunch. It's not the conversion loss, it's the sheer amount of energy (joules, kWh, BTU) that's the major issue. A 1000W heater would draw about 80 amperes. Two group 65 batteries typically have about 100 AH charge (charge = current * time). So even at 100% conversion efficiency, you're looking at 1.25 hours before the batteries are plum dead. And that's so dead that they might never take a charge again. So at best, if you had two batteries separate from the starting batteries, and maybe a 500W heater, you could maybe get 1.5 hours of run time, and then you'd have to run the engine long enough to recharge them. Would probably help some, but that's a lot of extra weight/space for not a whole lot of benefit.

 

[OLDBULL8]

A 1000W heater would draw about 80 amperes.

That's ~8 amps @ 120 VAC, not 80.

 

[madpogue]

That's ~8 amps @ 120 VAC, not 80.

At 12V, it's 80A.

 

[hce]

That's ~8 amps @ 120 VAC, not 80.

But the batteris are 12 volt so there would be a 80 amp load on the batteries before stepping up the voltage.

 

[laserjock]

Adding more batteries in parallel really has not down side that I can think of other than expense. If you already have them, it's not really any extra cost. Just remember by adding more batteries, you have a bigger bucket to refill if you drain them down so the alternator will be working harder.

The fact is with trying to heat with batteries, you just don't have the capacity. Forget the inverter loss for a minute because inverters are pretty good, you only get so many amp*hrs out of a battery. Group 31 batteries have about 125 amp*hrs. Standard starting batteries are about half that reserve capacity. A block heater is what 1000 watts? W=V*I so 1000/12= 83 amps. So figure you would get maybe an hour and it would take a large (like 2000 W) inverter. Also remember that the inverter probably won't use the entire capacity because it would be continous draw, no recovery time and most inverters shut off when the voltage starts to drop on the battery.

So I guess the answer to the question is it possible... I suppose it might be if 45 mins to an hour is enough time to do much in the way of heating the block in your climate. I'd think it would be time better spent adding an extra battery that you can loose in the summer to give you a little extra capacity to do an extra burn or two on the GPs before starting and maybe helping whip the thing over a little faster a little longer before the batteries go flat.

My 2 cents.

 

[hce]

Could install a remote starter. A good unit will have provisions for glow plugs and can be set to start every couple of hours and run for a set time.

 

[ironworker40]

Ummmm, new boss. what a ****. just sayin

Exactly what I was thinking.
I had a similar problem in 1989. Some ******* I worked with went to the company and complained that me and another guy were plugging our trucks in and STEALING from the company. So our foreman told us to stop because the head office was involved and he didn't want to hear it. Here is the kicker. The company I was working for had 1000's of vehicles plugged in every night, including 50 or so in the yard I worked in. The company was the electric company that serves half the state of nj.

 

[Brad S.]

I've thought about this same issue of truck being in the open when its cold.
Instead of a block heater, what about a oil dipstick heater...????
Doesn't warm the engine as much, but it takes less power....

 

[BDCarrillo]

Good points on the max run time of a 1kw heater... when I was thinking of running some it was only about 300 watts, to help preheat WMO. Wouldn't an intake air heater (like some tractors/rigs have) work well enough to aid a cold start? Shouldn't need but a minute or two to heat up.

 

[marmot]

How about some charcoal briquettes in an old cooking pot.

At lunch time, light them up, place under engine with a vertical shroud for wind protection. At 5pm, remove, douse with water/snow, put lid onto pot, crank warm engine and go.

You may need to add a horizontal shroud if your vehicle leaks lots of flammable fluids. Some pots have locking lids that will prevent spills, and are available at thrift stores for a few bucks. The shrouds can be any old piece of sheet metal.

A heck of a lot cheaper than extra batteries/larger alternator, and as reliable as dirt. Plus, you can use it for emergency warmth and cooking if stranded or camping.

I used this method to warm up a Detroit Diesel 8V71 in an inter-city bus.

Watched my neighbor incinerate his semi with a pan of charcoal when I was a kid, leaking diesel and it went up like a torch, pretty impressive to watch.

 

[maverick350]

If you could get around the initial cost of the webasto / espar coolant / cabin heater, I think heating the coolant and cabin with the small diesel heater should be more efficient than a cold start with the engine.

The redneck version is pretty easy to imagine, something like the biolite camp stove, forced air wood combustion with a coolant loop. coolant lines to the heater core. If it didn't thermo-siphon though, you'd have an issue.

 

[RocketScott]

If you could get around the initial cost of the webasto / espar coolant / cabin heater, I think heating the coolant and cabin with the small diesel heater should be more efficient than a cold start with the engine.

The redneck version is pretty easy to imagine, something like the biolite camp stove, forced air wood combustion with a coolant loop. coolant lines to the heater core. If it didn't thermo-siphon though, you'd have an issue.

This.

I keep watching craigslist for a used one. Lots of boats around these parts use them. Using a hydronic system would heat the engine and the cabin. You already have a tank of diesel sitting under the truck, might as well use it.

 

[Wyreth]

Cast your mind, if you will... We have all been there. Your boss won't let you plug your truck in while you're at work. You know the temps are "freakin' cold" and you dread having to go out there and exhaust your starter trying to crank it over. I was dreaming and came up with this:

An extra pair of batteries mounted on the side of the frame. These batteries are independent from the other two in the truck. They are hooked up to an inverter with your block heater hooked up to them.
Have a pair of switches like this going to your other batteries after use for when you need to recharge you batteries after use. http://www.zoro.com/i/G2699243/?utm...hopping_Feed&gclid=COWJ7K7b7MMCFQ4BaQodHH4A8A

It is an "Oh crap, my truck isn't going to start and I can't plug it in system. Just go out there and plug it into itself for and hour or two and it won't run down your batteries you need to make your truck start.
I basically couldn't sleep last night so I though up this design. I'm not sure if it would actually be feasible. I'm entirely certain that a larger alternator would be a must. So let me know what you think.

Is that a crazy idea?
yes.
is it doable, Hell yes. Simple in fact, here's how I would do it:

Figure you're inverter will have around a 95% power factor. (actually a very reasonable estimate with today's power supplies.) and you will want at least a 1500w inverter to run the 1000w block heater at 100% duty cycle without issue.

So now it's simple math. The block heater will draw 87.5A from a 12v system. (heater + power-factor / 12v) From a simple search on this board, depending on climate and wind, morning starts in extreme cold need you should set your plug in timer for 1-4 hours.

So you will need 88-355 amp hours of 12v battery to run your block heater. (also a simple timer.)

Lithium batteries for this would be light and cheap, but the charging system very expensive and there is always the risk of a class D fire when rapid charging lithium batteries. So I personally would go with deep cycle led acid. Little maintenance, and can simply be linked parallel to the starting batteries for recharge. 30 second google search gives me these: http://www.amazon.com/Vmaxtanks-VMA...TF8&qid=1424401618&sr=8-5&keywords=deep+cycle I know for certain you can find comparable batteries cheaper, buuuut I live in Vegas, (we don't have cold here) so I won't bother looking.

So a pair of those will cover you for 3.5 hours of block heater (numbers include some padding) That's enough for almost the max forum recommended heating time. Keep in mind 35A is that battery's regulated max charge rate. So unless you have a 6 hour commute, you will need to plug them in overnight each night to fully recharge them from 0.

I would add an RV battery isolator, and at minimum a 3g alternator. However this is totally doable. Cost might be steep, but then the batteries will likely last 3 years, and to have 3+ hours of 15A 120V on demand when not needing the heater. That really does make the idea a little attractive. Especially when you consider mounting the deep cycles in the stock battery locations and running a super capacitor array to start the truck. The batteries will keep the capacitors topped at 12v, and the isolator would keep the inverter from drawing down the cap bank. So you'd step into a truck that had a warm block, and the starter would still spin the flywheel off. All from that one pair of batteries. G31's really aren't that much cheaper, brand new retail, than the ones in the link I posted, and a Super Cap array is only $120ish for the capacity I would want. Crap, I'm talking myself into it.....

After some thought, it's still a crazy idea, and wouldn't be cheap.... But it's also not, all things considered, a bad idea.




When I joined this forum, replies to "crazy idea" titled posts had the tone of: "well I wouldn't do it, but if I did, here's how:" Not: "That won't work, and here's why:"

I miss the forum I joined. It was alot more fun.
Just sayin...

 

[laserjock]

When I joined this forum, replies to "crazy idea" titled posts had the tone of: "well I wouldn't do it, but if I did, here's how:" Not: "That won't work, and here's why:"

I miss the forum I joined. It was alot more fun.
Just sayin...

Thanks for the reminder. One guys crazy idea might be the next big thing.