Alternator Charge Voltage with extra battery.

IanH wrote:Here's what you do if you fit a second battery, this will be complex..............
1. You add 25 to 30Kg to the payload weight of the vehicle
2. You lose the volume of the battery as spare space, already somewhat limited
3. I could go on and on..............

There is, however, a much simpler and more elegant solution........

Put as many solar panels on the roof as there is roof area, only use glued on semi flexible ones, Google, Photonic universe as an example.......

Mine is 150w, only one battery, virtually never use EHU, don't need to.

Total weight of my installation....................6Kg. never had a battery low voltage issue!!!
 

Hi Ian

Just noticed your post. Clearly a man after my own heart.

If it ain't broke - don't fix it. 

Mr Evans

Comprehensive answer but you miss the point, I fear.........

The real reason for my 150w setup is to keep BOTH the LB and VB charged through the winter when the MH isn't used that much, anything else is a bonus

I also don't care if solar energy is wasted, if it lands on my lawn it just grows grass!

To make my first point to this response, I have absolutely no plans to install a second LB, there is no possible reason to and we have operated 2 MH's now for several years with the exact set-up we currently have

Hope this explains my views, oh, and BTW we NEVER go to Cornwall!!!

Bw
IanH

Gromit wrote:

IanH wrote:Here's what you do if you fit a second battery, this will be complex..............
1. You add 25 to 30Kg to the payload weight of the vehicle
2. You lose the volume of the battery as spare space, already somewhat limited
3. I could go on and on..............

There is, however, a much simpler and more elegant solution........

Put as many solar panels on the roof as there is roof area, only use glued on semi flexible ones, Google, Photonic universe as an example.......

Mine is 150w, only one battery, virtually never use EHU, don't need to.

Total weight of my installation....................6Kg. never had a battery low voltage issue!!!
 

Hi Ian

Just noticed your post. Clearly a man after my own heart.

If it ain't broke - don't fix it. 

Dave
Totally agree, wrote the bit above as you were writing yours!

Well that was a more 'Full On' reply than I expected?


I missed the point because it wasn't made in your post!!!!
Your post was all about Weight saving and space.

Even the second post went on about weight, with your "background in Aviation".
You wrote : Most people don't consider weight, my background is aviation and, surprisingly, under water engineering, both are weight vital.  


Only after I had posted did you say anything about the REAL reason for the Solar is there is to keep the batteries charged in Winter.


I am sorry I misunderstood the real reason for your post, it seemed to me that you were saying how a second battery was a waste of space and weight and prefer to annihilate the one you had rather than have the most efficient battery set-up? 
I obviously got the wrong end of the very light weight stick.


As for flexi Solar panels, even Sika say they should not be glued to a Motorhome Roof due to their construction being of, and I quote, 'Exotic materials' that rarely bond safely.

See our Solar panel page where we worked with Sika to create a safe standard for Solar Panel fixing and one single thread reported 4 taking flight :-
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Excuse me please, the purpose of me starting this thread was in an effort to create a sort of continuation of the very interesting and entertaining thread;
 
 
 
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The title of this thread is *Alternator Charge Voltage with extra Battery* so I just cannot understand why people post;
 
 
 
IanH Writes;
 
I have absolutely no plans to install a second LB, there is no possible reason to and we have operated 2 MH's now for several years with the exact set-up we currently have
 
And, shouts out,
 
Hope this explains my views, oh, and BTW we NEVER go to Cornwall!!!
 
Dave
Totally agree, wrote the bit above as you were writing yours!
 
 
Grommet writes;
 
Clearly a man after my own heart.

If it ain't broke - don't fix it. 
 
 
Apart from being totally off topic I find these comments rude and unnecessary, this thread is for people who have; want or need an extra battery, I think that is quite clear. I tried to be polite to some heading off topic, but that, I now feel was an error on my part it seems.
 
 
I think it would be a good idea if people who are using solar power and only need one battery, maybe even, no leisure battery at all, could start their own new thread headed appropriately, even another thread on how to travel and have 300kg of payload available for duty free. (maybe)
 
 
There seems to be a few who disagree with posts from AllaFEvans, which is fair enough, nearly everyone including the management seem to feel the same about most of my comments but could the people at least try to be polite to Allan, who it seems to me, is trying to pass on his wealth of experience and knowledge before something unpleasant happens to him.
 
 
Just my thoughts, no need to reply, please.

willconquerer wrote:Excuse me please, the purpose of me starting this thread was in an effort to create a sort of continuation of the very interesting and entertaining thread;
 
 
 
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The title of this thread is *Alternator Charge Voltage with extra Battery* so I just cannot understand why people post;
 
 
 
IanH Writes;
 
I have absolutely no plans to install a second LB, there is no possible reason to and we have operated 2 MH's now for several years with the exact set-up we currently have
 
And, shouts out,
 
Hope this explains my views, oh, and BTW we NEVER go to Cornwall!!!
 
Dave
Totally agree, wrote the bit above as you were writing yours!
 
 
Grommet writes;
 
Clearly a man after my own heart.

If it ain't broke - don't fix it. 
 
 
Apart from being totally off topic I find these comments rude and unnecessary, this thread is for people who have; want or need an extra battery, I think that is quite clear. I tried to be polite to some heading off topic, but that, I now feel was an error on my part it seems.
 
 
I think it would be a good idea if people who are using solar power and only need one battery, maybe even, no leisure battery at all, could start their own new thread headed appropriately, even another thread on how to travel and have 300kg of payload available for duty free. (maybe)
 
 
There seems to be a few who disagree with posts from AllaFEvans, which is fair enough, nearly everyone including the management seem to feel the same about most of my comments but could the people at least try to be polite to Allan, who it seems to me, is trying to pass on his wealth of experience and knowledge before something unpleasant happens to him.
 
 
Just my thoughts, no need to reply, please.

Clearly you have no sense of either humour or irony
NOTHING I said was RUDE or unnecessary, just a statement of what we do, in our near identical MH to yours, oh and BTW I didn't SHOUT!!!!

Hi Will.  I will be back with some readings to go/compare with yours as i stated  earlier. 

Please dont get upset ,thread drift happens a lot .so just ignore those that are not relevent.
  I have to agree with you about AlllaFEvans.His contribution is most welcome .

regards

Micky

The Autocruise (Swift) Select 164 with 4 x 110Ah habitation batteries has just gone and was quite a surprise.

The voltage at the habitation batteries with the engine running, but Fridge 'Off', was  a surprising 13.7v. No where near the 14.4v it should be, so woeful for fast Alternator charging, but much better than expected. 
I had anticipated less than 13.0v for such a large battery bank.

We then repeated the test with the Fridge 'On' and got a warning that the Starter battery voltage was below par, which made me take notice!!
 
We then detected different battery voltages across the bank, which I had expected to be all linked together.

Turns out that there were 3 battery banks, with the Leisure battery bank only having 2 batteries, hence the better than expected Alternator charge rate.

The '2nd' battery bank comprised two more batteries and had the Waeco Compressor Fridge wired directly to it. 

The third battery bank comprised of just the Starter battery.
However, we found the Durite Voltage Sensitive Relay for charging the Fridge battery bank had failed permanently 'closed', making the Starter battery 'part of the '2nd' Fridge battery bank'. Hence the warning the Starter battery voltage had dropped when we put the Fridge on.

The Durite VSR seemed to be an attempt to 'fast charge' the Fridge battery bank by giving it it's own dedicated low voltage drop, fat cable feed from the Alternator/Starter battery. 
That this achieved 14.35v charge at these batteries, even when the Fridge was 'on' clearly worked well.
It shows how effective fat, direct wiring from the Alternator can be.

That makes this vehicle special in terms of this Forum thread, because on the same vehicle we had 2 x twin battery banks wired 'to the Alternator' using different techniques, enabling direct comparison.
 
One charge path went via an EC600 using appalling installation practises and achieved a 13.7v Alternator charge, and the other used good wiring practises and charged at an almost perfect 14.35v.

Clearly one battery bank will charge optimally and the other at less than a mains chargers 'Trickle' charge rate. We would estimate the EC600 'driven' battery bank will take at least twice, if not 3 times, longer to charge.


In another thread on here one 'expert' stated that 'decent cabling will only improve a batteries charge rate by 10 mins in a 10 hour period. I think that statement has been shown for what it is. We did ask for evidence to back up the 'experts' statement, but none was forthcoming.


I don't understand why the original owner went down the path he did, but although the vehicle was '17' reg it wasn't working very well now.