Avoiding EHUs

Some of us have limited spending power and enjoy living within our means so when a member of the site shares there ideas on how to enjoy life in a Motorhome without spending huge amounts of hard earned dosh, I for one applaud them.

I would love to see the links to the batteries that never run flat and the tanks that never empty or is that as Northerner used to say "me failing to recognise Irony" or just old fashioned sarcasm.

Richard
 
Aethelric said:
Hi Beemer, the whole point of my exercise was that I don't have to check the clock I don't limit my electricity usage (OK, I don't leave the lights and computer on 24/7 but I don't do that at home either) and I'm not an electricity disciplinarian.
I'm sat in the van as I type this on the lap. I've been on it for two and a half hours. I've had a light and the radio on for most of that time. I've just turned the heating down as its 24C in here (10C outside). We have been living in the van this way for over a week. A trip to the shops and the launderette topped up what I'd used yesterday and the battery still has plenty spare capacity.

But its a big van you have there Beemer, I doubt if my techniques would work for you anyway.:)
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I am sure that if I was to study your article, I could use your techniques in my 'shed', hence why I stated that I found your article interesting, but i must have misunderstood it, because I understood that you must 'check the clock' to know, quote "overheads for about an hour", 10 mins at a time to heat up shower" and "watch TV for a few hours". My opinion (and it is only an opinion) is using your system you would need to 'keep an eye' on electric consumption, but if you say you don't, fine, I believe you. :D
DT Dog knows full well what teenagers are like for using electric, and my lad is no different. He was able to flatten the battery I allocated for just the TV in one evening, but because I had another two separate leisure batteries, I was able to maintain all other habitation power.
My solar panel is still charging all three batteries, this December month.
I just wanted to put my angle on your informative post.
 
We use LIon a lot at work, they do what it says on the box but it will be a while before I have a van that runs on them. :)

Richard
 
Hallo Aethelric,

many thanks for the article, i really enjoyed reading it. By the way, you have a very smooth style in explaining technical matters. Even for me being a little bit stupid, what electricity is concernd, and not very trained in reading technical matters in english, i did understand your message. Really good points to think about and adapt the one or other idea to my own "electrical MH-world".

Thanks again and merry x-mas

Bernd
 
I have a battery to battery charger fitted and found that charging time for the leisure battery was dramtically shortened. One hours drive is usually enough to get a decent charge in the 125Ah Leisure battery I have fitted in place of the 70Ah original. Also added a 100W Solar panel and in hindsight I should have cabled up to fit a second solar panel for cloudy days or winter. Lost opportunity.
All lights are LED and we have no TV. We can stay without EHU for days and days as long as we don't use the Truma fan blower 24/7.

Total cost just under £300 (done all the fitting myself) and I wouldn't want to miss it. I agree that thoughtful use of your ressources is the key, even with Solar etc fitted. But I feel much more relaxed knowing that I can run the fan blower all day if I feel cold.
 
AndyC said:
Always good practice to reduce power consumption to balance the power available, however the first thing I would have done is to optimise the power available by investigating why there was only a pitiful 4A getting to the leisure battery when driving.

AndyC
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That's explained in the article Andy.
 
Teutone said:
I have a battery to battery charger fitted and found that charging time for the leisure battery was dramtically shortened. One hours drive is usually enough to get a decent charge in the 125Ah Leisure battery I have fitted in place of the 70Ah original. Also added a 100W Solar panel and in hindsight I should have cabled up to fit a second solar panel for cloudy days or winter. Lost opportunity.
All lights are LED and we have no TV. We can stay without EHU for days and days as long as we don't use the Truma fan blower 24/7.

Total cost just under £300 (done all the fitting myself) and I wouldn't want to miss it. I agree that thoughtful use of your ressources is the key, even with Solar etc fitted. But I feel much more relaxed knowing that I can run the fan blower all day if I feel cold.
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I did consider some sort of battery booster, but its extra complication and I don't need. Of course depending on the vehicle and the way its used many folk will need all of this technology.
 
Can we get something straight.

The article describes the way I tackled the issue of avoiding EHU for MY situation.
I AM NOT FRUGAL WITH THE POWER IN THE VAN.
Don't assume I am comprising on power usage. I am not.
If I had an array of solar panels and a generator, and a trailer full of batteries I would not use any more power than I do now.
If I had a bigger van or if I needed to run fans to stay warm, or if I parked up without moving for more than three days, I would have come up with a different solution.
 
Very Interesting

Thanks , Lots to consider there .

In these days of deisel particle filters , is it a bad idea to run your engine on idle to charge your batteries , except in an emergency..... ?
 
Aethelric said:
I did consider some sort of battery booster, but its extra complication and I don't need. Of course depending on the vehicle and the way its used many folk will need all of this technology.
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Like Teutone I have a battery-2-battery charger which puts the full output of the alternator into the leisure batteries(2X 90ah). No solar.

But with this set-up we can top-up with about 15 mins driving a day when using the Truma. No need for EHU. except at home.

Once it is installed you just forget it - no complications.

Geoff
 
sparrks said:
Interesting Article. What was the voltage when the charge current was 4A?
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I can't remember sparrks, but it would have been maybe 0.2-0.4V lower than the vehicle battery.With maybe 0.1ohms in the circuit between the batteries due to cables, relay and the fuse, and my meter that gives 2-4 amps. Revving the engine had no effect. It would be higher without the meter.
 
Whilst the leisure battery would be about 12.5v, with the engine running the alternator should be pushing out 13.8-14.2 volts and if the leisure battery was discharged it would pull more than 4A. I don't disbelieve you, just trying to understand why the charge current was so low. I haven't got a split charge system (using a B2B) so am not familiar with them and their ways.
 
AndyC said:
Always good practice to reduce power consumption to balance the power available, however the first thing I would have done is to optimise the power available by investigating why there was only a pitiful 4A getting to the leisure battery when driving.

AndyC
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Yes, I was going to comment on that later. As an example, my BigRig has a 280Amp 24V alternator and it will pump 160Amps into the battery (obviously a big battery to match) when I first drive off in the morning and that will gradually taper off over a couple of hours to about 50Amps as the battery starts to get some charge in it. Proportionally a smaller system should put in at least 20 amps and get at least 15Ah into the battery during the first hour.
BUT as in all things, it depends. It depends on the state of charge of the battery when you start off. A nearly charged battery in combination with an alternator that drops its output voltage quickly in response to the state of charge of the starting battery, plus running through a diode-isolated split charger, plus a few metres of skinny cable and 4 amps might well be the best you can do. A couple of fairly minor changes and the charging current could increase significantly.

As for the poster actually criticising some of us for offering our well-considered and learned opinions - here is one just for you
pot-kettle-300x202.jpg


B2B chargers - mixed outcome there. For runs of one hour or less, a well-designed direct interconnect system will often put more AH into the leisure battery than a B2B, BUT once the run time gets to 2 hours or more, the B2B system will win.
 
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Excellent post.

I enjoy learning new practical things ......

Doris likes shopping

Some people like picking holes in any and every thing

Some people appreciate what others have achieved and that they are happy to share their achievements.


I for one, appreciate your shared knowledge.

Cheers
 
sparrks said:
Whilst the leisure battery would be about 12.5v, with the engine running the alternator should be pushing out 13.8-14.2 volts and if the leisure battery was discharged it would pull more than 4A. I don't disbelieve you, just trying to understand why the charge current was so low. I haven't got a split charge system (using a B2B) so am not familiar with them and their ways.
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You are right about the alternator but the 12.5v you mention for the leisure battery is when its discharging. If its charging it will go up to around 13.5-14V with only 4A.
 
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