[Dave.]

Evening all,
My leisure battery isn't lasting as long on a charge as before, so guess its time to replace.  Thinking of putting a split charge relay in to top up my battery between jobs.
My question, how many miles roughly does it take to make a decent charge, from a low battery warning?

Dave

[Spruce]

Dave

This is a very difficult question to answer.

My suggestion is to get onto the Sterling Products website and read each segment.

http://www.sterling-power.com

Years back the Ambulance service got into dire straights as their standard method of charging leisure batteries on board to run equipment wasn't working and hence putting patients lives at risk.

According to them (Sterling) an alternator is good at suppling your vehicle's power requirements but not good for charging batteries. The bottom line is that they ripped out all the standard alternator and split charge relay equipment and replaced it with a more sophisticated system that mimics multistage charging required by leisure batteries.

But for our requirements this is 'overkill' and far too expensive.

So in direct answer to your question, an alternator on a standard split charge relay will only ever top up or replace some charge in your leisure battery, but will never fully charge it. (I once read somewhere on an Australian motorhome website that it would take a drive of 750 miles to charge it - but can't find it now.)

Our experience over the last 6 years seems to bear this out. Most of our work is within a 6 mile radius of home but we do have a day where we travel further afield, a round trip of about 25 miles. During this time we have never had a fully charged leisure battery done by the van's alternator on either of our vehicles. (Citroen Relay and Peugeot Partner). We fully charge each of the batteries every couple of days with a proper multistage leisure battery charger. The one I use is supplied by Tanya, is a 10amp intelligent multistage charger for motorhome use and can sometimes be on for 2 - 3 hours.

I had to replace the Leisure battery in my Relay van about 6 months ago as it wasn't holding a charge for a days work, but was able to get by with running the engine to supplement the charge and on idle would still run 2 Shurflo pumps.

I have a theory.

If you estimate your pump runs 4 hours during an average working day, then in theory it will use about 24 amps if it draws a current of 6amps.  So if your leisure battery is a 110 amp one, in theory you will have 86 amps left in the battery at the end of the day.

I have a 30amp split charge relay protected by 15 amp fuses which have never blown in 4 years. So even when the old battery was flat, the charging current to the leisure battery never exceeded 15 amps, because if it did, then the fuse would have blown. Lets say my battery is being recharged by the van at 10amps it would take about 2.5 hours of driving to replace the used power, again in theory. And again, if it was charging at 15 amps then it would still take 1.5 hours to recharge it.

It's more complicated than this though as a battery will need less charging current as it becomes more fully charged - liken it to a toilet cistern filling up after the toilet has been flushed.

But even if your daily drive is longer than this, your alternator will never fully charge your leisure battery as it is not capable of doing so - it was designed to charge a crank battery quickly and not the characteristics of a leisure battery charging.

Also
http://www.sterling-power.com/images/downloads/alt%202%20batt/Alternator-to-Battery%20Chargers%20and%20Remote%20Control.pdf

Spruce

[Dave.]

Cheers Spruce,
Thank you for taking the time for such an in depth reply.  Going to work through the info on that website today. 
Picked up a new 85amp leisure battery yesterday,I've got most of the bits to wire in a split charge system, just not sure if the thin wire I can see on the alternator is the no charge light circuit?
Whilst I'm running cables from the front to back, I'm also going to wire in a constant live cigarette lighter socket in the rear, with 25 amp cable, so I can have easy access to the other battery, as back up, and also to power an amber beacon, charge phone etc.

I've always charged my leisure battery with a 6amp standard charger, usually for a few hours each evening - could this be whats killed my other battery in about 14 months - Think it's time to get a multistage charger 

Dave

[Spruce]

Cheers Spruce,
Thank you for taking the time for such an in depth reply.  Going to work through the info on that website today. 
Picked up a new 85amp leisure battery yesterday,I've got most of the bits to wire in a split charge system, just not sure if the thin wire I can see on the alternator is the no charge light circuit?
Whilst I'm running cables from the front to back, I'm also going to wire in a constant live cigarette lighter socket in the rear, with 25 amp cable, so I can have easy access to the other battery, as back up, and also to power an amber beacon, charge phone etc.

I've always charged my leisure battery with a 6amp standard charger, usually for a few hours each evening - could this be whats killed my other battery in about 14 months - Think it's time to get a multistage charger 

Dave

Dave,
We also used a standard battery charger for a while with mixed results. The first battery lasted 9 months on the trailer system I had and I put it down to the weather as the original battery on the trailer bought new lasted about the same time. The same make a size of battery lasted 4 years in my sons van and the 120amp unit I had on my van mount lasted about 3 years. They were cheap batteries from a local caravan center.

We have recently replaced both with Numax along with the charger and things are going OK at the moment.

Knowing what I know now I would again go for the intelligent split charge relay which only needs one cable from the battery through the relay and then connected up to the leisure battery. Once the starter battery on the van has been recharged (about 40 secs) the relay kicks in and the leisure battery gets a charge.  They are much easier to connect up and you don't have the mess on with the extra charge wire from the alternator.

The first 3 split charge relays were this type, but the one on my son's van 'blew' so it was replaced with one of these.

http://www.ebay.co.uk/itm/SPLIT-CHARGE-RELAY-12V-30AMP-SELF-SWITCHING-REGIUS-/200638338954?pt=UK_Campervan_Caravan_Accessories&hash=item2eb6fa178a

Spruce

[Dave.]

Thanks again Spruce,

I was looking at those relays, but found a 30 amp relay in the shed, so I was going to use that.  Just ordered the heavy duty one on eBay, will be easier to fit.

Will sort out an intelligent charger next week


Dave

[Paul Coleman]

I have a split charge relay.  I find it very useful as I can use the leisure battery for a number of days if I need to - particularly if I am doing a lot of drive betweens.  However, leisure batteries last a lot longer if they are not allowed to run down too much.  Therefore, I have one in the van and one on charge.  I change them over every other time I fill the van tank (every time if the van has been stationary on large jobs).
When these leisure batteries become depleted as they get older - i.e. they don't even last a day when on a relay - I take them both out with me and swap them over half way through the day.  I may even let the engine run while I'm having a break (in the van) in order to squeeze a bit more from it.  This can cost in diesel if done too often though.
Basically I have two chargers.  I charge up the two older ones while the newer one is in the van - then rotate it.  Obviously there comes a point where thew two older ones become unworkable so then I buy a new one - and rotate it with the newer battery (hope this makes sense  ).

[Dave.]

Makes sense to me, Paul

I was going to pick up one of those mini solar panels that they use in camper vans to keep the old battery topped up in the shed - and then hopefully I've always got access to a battery that could give me a few hours work in emergency - whilst the other is recharging.

[♠Winp®oClean♠]

Wouldn't it be better to use a large top of the range car battery like a Bosch silver 5 series instead?

I power my pump direct from the van's own battery which is a 63Ah Bosch as above. Can run it all day without a hint of power loss! Bear in mind though, it won't do this without electronic control for your flow rate. My 100psi shurflo runs on setting 1 or 2 all day with no problems. 8mm hose helps to keep the power consumption down.

[Ian Sheppard]

an Alternative would be a Pump Controller with Charging capacity the split relay is built into the Unit, the leisure battery is charged from the Alternator once the engine is running. as For charge time there is no fixed answer.

You can get the charging controller from the Usual WFP distributors.

[Dave.]

Next time I need a controller I'll get the charging option.
For now, it's going to be a £12 relay from eBay - and in due course an intelligent charger.

As we're on the subject of of chargers, bateries etc - does anyone know if the digital controllers  reduce the voltage and the current used?

I use my controller on 40, a little higher on first cleans.  It's a 5L min vyair pump which is rated at 8amps - so I'f I'm running at less than half its capacity - is it fair to assume that I'm using under 6 volts and 4 amps?

I was much happier when it just worked OK, and I charged it each evening.

Anyway - the new 85amp/h leisure battery that I picked up on Saturday has been fine, and I've got my work done by two thirty
 

[SherwoodCleaningSe]

I'd say the 3 essential things are in this order.

1. A good intelligent charger like a ctek
2. A good leisure battery like an AGM, very expensive but well worth it.
3. A split charge relay.

Charge the battery after every heavy day, if your doing a 5 day week I'd say you should be charging with the intelligent charger at least 3 times. It's true you can get by only topping the battery up every so often, but the battery will last several times longer with regular bench charging.

Simon.

[Ian Sheppard]

Next time I need a controller I'll get the charging option.
For now, it's going to be a £12 relay from eBay - and in due course an intelligent charger.

As we're on the subject of of chargers, bateries etc - does anyone know if the digital controllers  reduce the voltage and the current used?

I use my controller on 40, a little higher on first cleans.  It's a 5L min vyair pump which is rated at 8amps - so I'f I'm running at less than half its capacity - is it fair to assume that I'm using under 6 volts and 4 amps?

I was much happier when it just worked OK, and I charged it each evening.

Anyway - the new 85amp/h leisure battery that I picked up on Saturday has been fine, and I've got my work done by two thirty
 

Bit slow this week

The Digital controller takes next to nothing, the biggest volt and current drop seems to be due to the length and quality of the wiring.
the current draw is running your pump. so a digital controller should nor reduce current or voltage at all. With the Eco Flows We have taken out the DE detection on test so we could run the controller at 50% above normal working and still did not manage more than 5 amps draw for the pump.

[Dave.]

Thanks for all the advice, just wired in the heavy duty split charger, got a hard wired inteligent charger too, additional 12volt constant live in the back of the van too and a new leisure battery too.

Electrically sorted

Dave

[Spruce]

Hi All
This charging of leisure batteries has been bugging me of late, so I did a little experiment the other evening.

In preperation for this I fully charged my leisure battery using my Numax Intelligent Charger then worked all day the following day.

When I got home I put the leisure battery on my 'old' Autocare 6amp charger to charge up. After a couple of hours the red charging light on the Autocare turned orange and then to green indicating that the battery is fully charged.
I then disconnected the Autocare charger and coupled up the Numax charger to see what the outcome would be. Now from what I have gathered from the sales spiel about why we need to use a 3/4 stage intelligent charger to charge our leisure batteries is that an ordinary battery charger will 'short fill' leisure batteries giving us about 25% less working capacity. So I naturally thought that the Numax would carry on charging the battery up to its full capacity that ordinary chargers won't do.

However, this wasn't the case. The Numax charger immediately showed the battery as fully charged and then went to float charging.

This tells me 1 or 2 things.

Firstly, do we need an expensive 3/4 stage battery charger for wet cell leisure battery charging? Or secondly, am I missing something important in my experiment, ie did I leave the battery long enough for the voltage to stabilise before coupling up the Numax charger to resume the charging regime and make the experiment null and void, or does the 3/4 stage battery charger really come into its own over long term battery management?

What do you think?

Spruce.

[Dave.]

As the battery was reading a full charge, the intelligent charger would read this too and go straight to trickle or maintenance charging?

If the  battery, in it's discharged state, was put on intelligent charge - I think it goes through the pulsing and consolidation stages to give it a better charge. 

Apparently, when a battery is knackered, some of the cells are over sulphated, which reduces it's potential workload capacity. An intelligent battery charger can semi-rescue some sulphated batteries, providing they have an output above 7 or 8 volts or thereabouts.

I'm going to do an experiement in the next couple of weeks with my old battery, to see if it's capacity improves

Dave

[dave.e]

i had all the's problems till i was told to run of the van battery. i have been running of the van batt now for 6 months my set up is a shurflo 100 psi 5.2 lt per min and a flo con on setting 60 all day with no problems what so ever and the best bit is no more charging ruddy battery's up all the time ace