Rednecktek
Solar Wizard
I don't want to scrape off the moss to find out, we have a symbiotic relationship and I don't want to make it angry. I can verify that we don't tan however, we just rust.
How can I power diesel heater since solar is probably going to be almost useless in winter when I want heat most?
- Thread starter Gueyog8a7
- Start date
I got the panels installed on the roof and the wiring in the van yesterday. Connected all up and still was drawing only 2-3 wattsI don't want to scrape off the moss to find out, we have a symbiotic relationship and I don't want to make it angry. I can verify that we don't tan however, we just rust.
. There was the odd jump to six but only for seconds.Also I still didnt get the more batteries thing. You did not answer how more will help when it is not able to even fill one?
Adding on more panel to take me from 2-3 watts to maybe 4 watts seems indeed hopeless as originally stated.
I got the panels installed on the roof and the wiring in the van yesterday. Connected all up and still was drawing only 2-3 watts
Also I still didnt get the more batteries thing. You did not answer how more will help when it is not able to even fill one?
Adding on more panel to take me from 2-3 watts to maybe 4 watts seems indeed hopeless as originally stated.
We're you testing at night ? Or under a tree perhaps?
Rednecktek
Solar Wizard
So either you had UK weather or the batteries were full.I got the panels installed on the roof and the wiring in the van yesterday. Connected all up and still was drawing only 2-3 watts
So say for example numbers you use 500wh a day in power and you have 300w of panel that in decent weather can produce 1200wh, and a bog standard 1200wh LFP battery for napkin math purposes.
Monday is cold so you're running the heater, but the sun is out so the panels can generate everything you use just fine. Then Tuesday you realize that you live in the UK and the clouds roll in. Because it's cold and rainy your panels can only generate 100Wh that day. That's OK, because you've got 2 days worth of power in the battery if you are careful. Weds is raining and the sun stays on holiday but you're still OK for tonight. Thursday morning the power goes out and the heater shuts off because the battery is done. If the sun comes out Thursday you'll get that charged up in a day and be able to fire up the heater, but if not you'll have to fire up the engine or a generator and let it charge up the battery.
But then your system realizes that it's the UK in winter and the sun takes its two weeks holiday to France. With your 1 day in the battery you're having to hope the sun comes back every other day at least, or run the engine for a while every day. Now if you had 3 batteries you would have 6 days of battery to keep you warm. Yes, you're using 500Wh a day, but if you're generating 1200Wh that'll start catching up pretty quickly. You don't have the roof space to make an uber-array that could refill all 3 batteries in one shot, physics just isn't your friend on that one, so the goal is to be able to generate more than you use On Average. If you do have to fire up a generator you'd be best off to have a good heavy duty charger to plug into your system so you only have to run the generator for 3 or 4 hours to top off the entire battery bank for the week rather than running it for an hour every two days.
Think of batteries kinda like a petrol tank. Your van may have an 100l tank and you're burning through 10l a day in fuel. You can fill it with 20l cans every couple days (single battery), or you can fill the whole tank all at one visit to the station (generator and 3 batteries). The cans take less time each to put in the tank, but it's not that much longer to just hit the station and only do it once. **
The biggest issue with a single battery is that you have to be able to get hours of direct sun every single day and if you don't, you're in the cold and dark.
With the environment you're in you'll want every watt you can get because you don't have the physical space to make a large enough array to compensate for fall/winter in the UK. I have the same issues out here in the Pacific Northwest where summer is "those 3 days in August" I've had to oversize systems over 300% and it still doesn't quite keep up, but by getting more panel on there, I only had to take the battery pack down to recharge the system maybe twice a year.
I use many of those diesel heaters at my camp and while I was out there for a couple months I found that in my pump house with it recirculating the air in an insulated building it used about 25 watts per hour running on the lowest setting which is completely reasonable for a van build. That means a single battery is only going to last about 2 days.
If you're only getting 2-3 watts out of your panels, hopefully it's just that the batteries are full.
**Please forgive my bad English to English translation.
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You can consider increasing the batteries, preferably LiFePO4, and add a beefy charger.
Increasing the battery capacity will only extend the period till they are empty: You still need to source the juice somewhere and sun isnt going to do that in wintertime.
But when shopping you can hookup the car and with a big charger you can actually put a noticeable amounf of power into the batteries and will allow you to use a EV charging pole during your shopping and charge the batteries in that time. Assuming you have a 100A charger (either dedicated or eg the one in a Multiplus 3000 which is 120A) you can charge 50-100Ah in a single hour during your shopping.
With a slow charger you also can but that will require you to stay overnight or so to have sufficient charge
With lead-acid you still can, but thats rather limited in terms of accepting high charge rates (/ not recommended)
Increasing the battery capacity will only extend the period till they are empty: You still need to source the juice somewhere and sun isnt going to do that in wintertime.
But when shopping you can hookup the car and with a big charger you can actually put a noticeable amounf of power into the batteries and will allow you to use a EV charging pole during your shopping and charge the batteries in that time. Assuming you have a 100A charger (either dedicated or eg the one in a Multiplus 3000 which is 120A) you can charge 50-100Ah in a single hour during your shopping.
With a slow charger you also can but that will require you to stay overnight or so to have sufficient charge
With lead-acid you still can, but thats rather limited in terms of accepting high charge rates (/ not recommended)
That takes a bit of setting up but is well worth looking into
I think OP is strapped for cash so I wonder if blue equipment is really in the picture ?
Rednecktek
Solar Wizard
No, that actually makes sense. While I was up at the camp there were more than a few days where it was so overcast that my 400w array (2x 205w 37VoC panels in SERIES) was only getting 15v and 0.1a through the EPEver. It was just really, really dark.
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Solar output is very low nowadays. At this moment its very cloudy here, rain/light snow. So light is not much. And still its brighter than some of the previous days.
The solar array on our company roof (160 panels of 410Wp, total of 65kWp), has only peaked at 4.5kW today.. which is like 6%. And that is at an angle installed.
Add dust/moisture/snow and flat mounting you can imagine even 400-800Wp isn't going to do much if anything at all.
The solar array on our company roof (160 panels of 410Wp, total of 65kWp), has only peaked at 4.5kW today.. which is like 6%. And that is at an angle installed.
Add dust/moisture/snow and flat mounting you can imagine even 400-800Wp isn't going to do much if anything at all.
With thick cardboard boxes over the panels.
Yes but having said all that you were actually advocating for charging by other means to fill up multiple batteries which was not clear from your previous comments.So either you had UK weather or the batteries were full.
So say for example numbers you use 500wh a day in power and you have 300w of panel that in decent weather can produce 1200wh, and a bog standard 1200wh LFP battery for napkin math purposes.
Monday is cold so you're running the heater, but the sun is out so the panels can generate everything you use just fine. Then Tuesday you realize that you live in the UK and the clouds roll in. Because it's cold and rainy your panels can only generate 100Wh that day. That's OK, because you've got 2 days worth of power in the battery if you are careful. Weds is raining and the sun stays on holiday but you're still OK for tonight. Thursday morning the power goes out and the heater shuts off because the battery is done. If the sun comes out Thursday you'll get that charged up in a day and be able to fire up the heater, but if not you'll have to fire up the engine or a generator and let it charge up the battery.
But then your system realizes that it's the UK in winter and the sun takes its two weeks holiday to France. With your 1 day in the battery you're having to hope the sun comes back every other day at least, or run the engine for a while every day. Now if you had 3 batteries you would have 6 days of battery to keep you warm. Yes, you're using 500Wh a day, but if you're generating 1200Wh that'll start catching up pretty quickly. You don't have the roof space to make an uber-array that could refill all 3 batteries in one shot, physics just isn't your friend on that one, so the goal is to be able to generate more than you use On Average. If you do have to fire up a generator you'd be best off to have a good heavy duty charger to plug into your system so you only have to run the generator for 3 or 4 hours to top off the entire battery bank for the week rather than running it for an hour every two days.
Think of batteries kinda like a petrol tank. Your van may have an 100l tank and you're burning through 10l a day in fuel. You can fill it with 20l cans every couple days (single battery), or you can fill the whole tank all at one visit to the station (generator and 3 batteries). The cans take less time each to put in the tank, but it's not that much longer to just hit the station and only do it once. **
The biggest issue with a single battery is that you have to be able to get hours of direct sun every single day and if you don't, you're in the cold and dark.
With the environment you're in you'll want every watt you can get because you don't have the physical space to make a large enough array to compensate for fall/winter in the UK. I have the same issues out here in the Pacific Northwest where summer is "those 3 days in August" I've had to oversize systems over 300% and it still doesn't quite keep up, but by getting more panel on there, I only had to take the battery pack down to recharge the system maybe twice a year.
I use many of those diesel heaters at my camp and while I was out there for a couple months I found that in my pump house with it recirculating the air in an insulated building it used about 25 watts per hour running on the lowest setting which is completely reasonable for a van build. That means a single battery is only going to last about 2 days.
If you're only getting 2-3 watts out of your panels, hopefully it's just that the batteries are full.
**Please forgive my bad English to English translation.
Solar harvesting nothing in winter isn't surprising at all - I think some folks in different climates don't understand just how dark it can be in the daytime in some climates, and for days on end. I'm in the PNW of the USA, very similar climate to the UK, and there's a reason why so many people in this area have a vitamin D deficiency. Plenty of time during the winter, my 1640w array doesn't even harvest enough to offset what the MPPTs are burning. Keeping solar on actually costs me ~22w.
Peltier junctions are cheap on Amazon, I'd be looking at building a thermoelectric generator. Sandwhich a few peltier junctions between aluminum heat sinks, put one side in the output stream from the heater, put a fan on the other side for cooling, series up enough junctions to get the voltage you need, and hook it into a cheap PWM solar controller. Sounds easy enough on paper, eh?
You'll have to start the heater on battery, but hopefully the thermoelectric generator could take over and even replenish power after it's started. You might not be able to run the heater on high, or the TEG may only offset some energy consumption, obviously depending on how much power you manage to harvest.
There are commercial TEGs, but they're expensive. You could do a lot of DIY tinkering before you get to the price of a commercial TEG.
Peltier junctions are cheap on Amazon, I'd be looking at building a thermoelectric generator. Sandwhich a few peltier junctions between aluminum heat sinks, put one side in the output stream from the heater, put a fan on the other side for cooling, series up enough junctions to get the voltage you need, and hook it into a cheap PWM solar controller. Sounds easy enough on paper, eh?
You'll have to start the heater on battery, but hopefully the thermoelectric generator could take over and even replenish power after it's started. You might not be able to run the heater on high, or the TEG may only offset some energy consumption, obviously depending on how much power you manage to harvest.
There are commercial TEGs, but they're expensive. You could do a lot of DIY tinkering before you get to the price of a commercial TEG.
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Someone else working on a TEG self powered diesel heater.
Now I'm curious about one of these myself. I've been pondering a diesel heater to test with waste motor oil, see if I can heat my shop and dispose of the waste oil at the same time. This might let me harvest some power from it as well.
I asked about this before even getting electrics installed. It defeated the purpose in my mind to have a diesel heater if it relies on another power source to run! I looked into other options and seems before widespread electric and stil in poorer parts they run kerosene with open flame but is said to be much more dangerous and also fumes not good for you as well as it would not be dry heat which is what my van is wanting most.
Have yet to look at the videos to see how practical it may be as limited with my internet time.
eXodus
Solar Addict
- Joined
- Jul 27, 2020
- Messages
- 1,483
LFP doesn't freeze at 32 fahrenheit. 0C, but you shouldn't charge them at full speed at those temperatures.
Since most people don't have charge controller with low temperature "limiting" a low temp cut-off is one way of protecting the batteries.
mikefitz
Solar Wizard
- Joined
- May 28, 2020
- Messages
- 3,040
Fit insulation, this is the first stage of van conversion.
This the recirculating heated air, not the combustion air for the heater. Your hob/ heater will recirculate .
This takes a small amount of power once running but the start up cycle, around 10 minutes, takes more.
Using the Wallas Duo as an example, startup current is 8 to 10 amps and running current less than 1 amp, ( in the region of 0.8 amp).
Power needed. Regardless of battery bank capacity you will need a charging source. In UK winter, with horizontal panels and perhaps shade, there won't be much solar input. Off grid, the best solution is a battery to battery charger using alternator power.
Estimating electrical power for your heater. Example 6 starts per day, 12 hours run time. Startup power 6 x10 amps x 1/6 hours = 10 Ah.
Run time power, 12 hours x 1 amp = 12Ah. Total power per day heating, 22 Ah.
Engine run time with a 60 amp battery to battery charger, 25 minutes, to restore battery capacity.
With better insulation, including window insulation, the heating requirements will be much less. Self adhesive closed cell foam direct on the metal,
10mm Closed Cell Foam Car or Van Adhesive Waterproof Insulation
10mm Closed Cell Foam Car or Van Adhesive Waterproof Insulation This easy to install black closed cell foam waterproof insulation is ideal for roofs, doors, wheel arches, boot and parcel shelf applications. Once fitted this product will improve the ride quality in your vehicle by reducing engine...
www.carinsulation.co.uk
Trying to survive off grid in the UK winter is not easy. Heating will be the least problem, water, washing and toilet needs, doing the laundry , finding somewhere safe to park.
That just reads like anti vanlife propaganda, All those other issues I have already solved easily like many others. Washing and toileting there are many options. Making power there are not.
Safe to park? This is not wartorn Ukraine or Syria
. As long as you are not intentionally driving into the worst areas in big cities the worst you will get is maybe a knock telling you to move on.Powering up and down 6 times per day why would anyone do that if they are running 12 hours at a time?
I have been in my van sleeping to -6c with no heating so far. It wasn't fun getting out of bed but it was fine in bed and that was exceptional. Most nights have rested around 0 to 4 c. I think I could manage with no heat at all except that it is important for drying out the van.
For my use case I see 2 startups max 1 in the morning for heating and cooking and 1 in the evening about 1 hour to 2 hour each time. I live in a van to be out and about not stuck inside it all the time. Granted I could be in it for a few days in a bad weather spell but even then I have waterproofs and warm clothes but even if I stayed in it would be a couple of days in the worst weather not weeks on end.
I didn't get into this for a luxury lifestyle I like minimalist living
.rodrick
Free energy enthusiast
Check this out maybe it would work for you constructed properly
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