Charging systems

  • Thread starter Thread starter windyjools
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Easiest way to fit terminals is to get the right size for the cable and then they crimp on firmly quite easily in a vice or pliers. - I used these for 25 mm sq cable which I already had from somewhere else 25/6mm Lugs * 10 - Tube/Lugs - Terminals - Raw Components Ltd - Auto electrical Supplies - Specialists in Split Charge Kits

If you can find the d+ wire from the alternator you can use an ordinary relay like this 100 Amp 12v Relay - 12V - Relays & Holders - Raw Components Ltd - Auto electrical Supplies - Specialists in Split Charge Kits

Otherwise you will need a voltage sensing relay will be easiest to fit and least likely to interfere with a modern vans electronic control unit Intelligent "TIMED" Voltage Sensing 100 Amp 12v Relay - Intelligent Relays - Raw Components Ltd - Auto electrical Supplies - Specialists in Split Charge Kits

Sorry about the commercial links – but I can’t see another way to illustrate what I am talking about. I am nothing to do with RAW components, but have bought a few items from them in the past with no problems.
 
Thanks to all!!

Thanks for all the replies.......as I suspected, there are as many ways to solve the problem as you care to look at. I currently run a 175watt solar panel through a 20 amp regulator to help the batteries but have a 12 volt compressor fridge which hammers the batteries!! Anyone who wants more details, I can promise I will put you off compressor fridges for life (I won't fit one in the next conversion that's for sure)
So, I'll be looking for a decent relay and some hefty cable to see if that does the job. I posted a similar question on on of the motorhome forums and got surprisingly similar response (i.e. keep it simple and use hefty cables and relay).
Keep the info coming though, anyone who wants info on compressor fridges, please fire away......I still have a new one that has a faulty thermostat that Waeco won't believe has a problem,,,,,,,,,but that's another story!
 
A Winters Tale.

Like Bernard, I also use a heavy duty 100 Amp (continuous) split-charge relay and 25mm (170 Amp) flexible cable to link to my leisure battery. Leaving out the fuse from the circuit WILL reduce the resistance and make the circuit more efficient, in the same way that using a 6 inch (copper) nail in your home lighting circuit in place of the 5 Amp fuse or mcb would make it more electrically efficient! As long as nothing goes wrong within the circuit, everything will be fine.

Feeding the cable through hose will help to add to the insulation and the abrasion resistance, but will not protect against all eventualities, whether caused by electrical faults within the circuit, or by external damage. A great example of this happened to me on a freezing cold night last winter, but luckily the vehicle involved was parked at home at the time instead of at some remote wilding spot.

The short version of the story is that one or more rodents, probably rats, decided to enjoy the warmth of my engine compartment after I'd parked up for the night ( most likely members of the infamous "wildcamping for rodents club"). After chewing through a large rubber grommet in the bulkhead, they had a feast on the cable insulation behind the facia. Luckily, at some stage this caused a fuse to melt, so saving the rats and the vehicle from going up in flames.

My point is this: I would much rather waste some electrical efficiency, and incur very slightly longer charging times by having a fuse in every circuit. A melted fuse is inconvenient, but much better than a melted cable, battery, alternator etc. and the possible total loss of your vehicle!

As for fitting heavy duty lugs to your cable without a h/d crimper, try using a vice or a lump-hammer and punch.

(Incidentally, the rats had made such a good job of hiding their handiwork from view that I couldn't find the reason for the blown fuse or inoperative fuel injection system the next morning. Neither could the AA man that I called out later, although I did earn some brownie points by towing his van out of a snowdrift with my 4x4!)

PS.. Rats and mice will often be attracted to your warm engine bay on a cold night, and are well known for starting fires by chewing on cable insulation.
 
The infamous charging system debate raises its head again.
There are many ways to skin this cat, some cheap, some expensive, some simple and some complicated. All work to a degree but this depends entirely on your own power requirements and you must also factor in your own space requirements, i.e how many batteries are you prepared to carry against how much power you need. Also you need to remember that what works for one van does not necessarily work for another.
Right the one thing that doesn't change and this is important as it should effect how you go about desining your charging system.
A vehicle alternator will only charge what ever batteries you have installed to about 80% of their actual capacity. Why, because it uses a cheap easy to manufacture voltage regulator that charges at a flat rate of 14.4v. It doesn't take into account things like, temperature voltage drops down cabling and the flat rate of charge just isn't capable of charging your battery much. A bigger alternator will charge your batteries quicker, but still only to about 80% and all split charge relay systems are the same about 80%.
If you decide you need to get the most out of your batteries then you need to replace the standard voltage regulation with something a bit more clever and this costs money. Not everyone needs this kind of system and for them the simplier solutions work just fine.
Personally i run an adverc advanced voltage regulation system with blocking diode and a good friend of mine runs a sterling battery to battery charger. Both have proven to be very relaible and efficient. Mine was a little more complicated to fit and was slightly more expensive but has the capability to charge the main as well as leisure batteries to a much higher level. Makes starting the van in -25 degrees much easier and this is important for me and was one of the reason why i went down this route. There are other reasons too.
 
Rats and mice will often be attracted to your warm engine bay on a cold night, and are well known for starting fires by chewing on cable insulation
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Amazing what as a newbie to Campervanning you find out on this forum....that's one I wouldn't have known about until perhaps faced
with the problem. Any tips for discouraging them....would one of the small home ultrasonic plugs do the job if put in the glove compartment
etc?
 
I take your point about rats scampa, but I have fed the cable through car heater hose wherever it touches metal, and I have not heard of rodents chewing through that?
I think it also depends where the cables are. Rodents prefer to be in places where they are hidden from predators, hence they were living inside your dashboard. I learned that the hard way when I covered a stored sofa with a blanket to keep it clean and found them living underneath the blanket!
The thing about voltage drop through fuses (and/or minimum size cables) is that in most cases it doesn't matter. As a very approximate example, if there is a voltage drop of one volt in the wiring to your spotlights you won't even notice. But if there is a voltage drop of one volt in the wiring between your main and leisure battery you would have to run your engine for about twice as long to charge it.
 
Harmergeddon said:
A vehicle alternator will only charge what ever batteries you have installed to about 80% of their actual capacity.
Click to expand...

I've checked mine with a hydrometer, which I was taught is the most accurate way to check them, and they are showing fuly charged :idea-007:
Sorry, but I think you have been reading too much sales literature.
 
Heavy cable without fuses!

Crimping with a vice!

Quite a few people need to read some literature, including the terms and conditions of their vehicle insurance certificate (unless you have had the installation passed as safe by a competent person and informed your Insurance company).

Far better to solder joints and fit appropriate rubber sleeves to fittings.

Better still, do not risk an expensive motorhome by saving a few pound.
 
Bernard Jones said:
I've checked mine with a hydrometer, which I was taught is the most accurate way to check them, and they are showing fuly charged :idea-007:
Sorry, but I think you have been reading too much sales literature.
Click to expand...

I didn't believe them either so i checked too. I removed my batteries from my system left them overnight to equalise and found before the system was fitted 77%, after 95%. Did you remove your batteries and leave to equlaise before checking?
 
Harmergeddon said:
I didn't believe them either so i checked too. I removed my batteries from my system left them overnight to equalise and found before the system was fitted 77%, after 95%. Did you remove your batteries and leave to equlaise before checking?
Click to expand...

I have no need to remove any batteries because I am only measuring the leisure battery which has nothing connected to it when I am not using the van. I just check the leisure battery with a hydrometer when the van has been parked up at home for a few days, effectively disconected, and find it showing about 1280 (the middle of the green sector) on the hydrometer scale. (Having had the journey home to charge it a few days previous)

How are you measuring the charge as a percentage?
 
I compared both the specific gravity and the open circuit voltage against the manufactuers figures.
 
well, after reading whatever I could find about batteries I have decided to fit a battery to battery charger.

came across this Power Integrator
and quite like the idea of having just one box to deal with the charging and I can add a solar panel (or two) at a later date once I have an idea of how much power we really consume.

the other choices are Ctek and Sterling. but that will be another long read to find out what I may need or not.

Battery I want to use will be a good quality flooded type. From what I read they seem to tolerate the higher currents better when using a B2B charger. So the money I save on buying the "cheaper" type can be invested in a larger battery which then (hopefully) get's discharged less than a smaller "better" battery and live a long and happy live.
 
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