[AuRavelling79]

Those of you who use a separate battery (but which is also charged by your van alternator when the main battery is full) - what size in AH do you use and why?

[DaveG]

2 x 85a joined together

[p1w1]

110 banner, mainly piece of mind it will last all day (6-8 hours)

[richard groves]

A 55 Ah
Because..........
1. my 110 was dead after about 4 years and was very heavy
2. it only cost me £35 delivered on Ebay
3. Its half the weight and size of the 110 and is easily carried up to my first floor flat from my van on a Friday night for an additional bench charge if needed

Impressed enough with it after about 4 months use that I may just buy another and keep one charged up and alternate between them.

[Spruce]

Those of you who use a separate battery (but which is also charged by your van alternator when the main battery is full) - what size in AH do you use and why?

110 amph. Why? Because its enough for our day to day requirements.

How many liters of water a day do you use on average? Whats your flow at the brush head in liters per minute?  Dividing usage of water a day by flow at the brush head will give you a good idea of how long the pump has run that day.

If we work an 8 hour day doing residential, then we expect to spend about 1/2 that time cleaning the glass. So the pump will run for about 4 hours.  (That's our experience. We spend more time on the glass doing large commercial work so we expect to use more battery power.)

With a digital controller our Shurflo pumps draw about 4.5 amps each. 4 hours at 4.5amps = 18 amps.

So a full 110 amph leisure battery will be left with 92 amps with one pump running. 2 pumps running will draw 36amps leaving 74 amps in the battery.
74 amps is about 75% charged roughly.

We don't travel very far so the alternator does very little to charge the leisure battery between houses and on the way home. Today coming home the battery was being charged at 7.5 amps for approx 15 minutes. So we used approx 27 amps but only replaced 2 amps. So we are down by 25 amps today.   

If I leave the van alone for another few hours and look at the voltmeter, I will probably see that the battery reads 12.6v so would be about 75% charged. Tonight I will plug in my leisure battery charger and leave it on all night.

In the summer I usually charge my leisure battery every second night, but in the winter I will charge it every night when I put the heater in the back.

We've had 2 single operator vans and in each case an 85 amph leisure battery was more than enough. The second van did a lot more mileage and SIL didn't have to charge his battery as often as we have to.

BTW, its not about how far you travel a day, its rather how long it takes to get there. My van charges the leisure battery the same on idle as it does 'bombing' down the motorway. In other words, if it takes 5 minutes to travel 5 miles then the battery will get 5 minutes of charge. If it takes 60 minutes to travel 5 miles then the battery has received 60 minutes of charge. The distance travelled is the same.

The other interesting thing about alternator charging is this;

If I go out with a fully charged leisure battery and run the pump for 10 minutes, I would expect to have used about 3/4's of an amp (0.75). Although I was drawing current at 4.5 amps my alternator will probably only replenish that at 1 - 1.5 amps an hour dropping to about 1/2 an amp. The fuller the battery gets the slower it accepts a charge. So 10 minutes work could take a lot longer traveling time to replace that; maybe an hour or so.

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[AuRavelling79]

Thanks chaps - especially Spruce for his in depth answer.

[Spruce]

This alternator charging is quite complicated.

We live on Teesside. About 2 years ago I drove my van down to London. When I started off my leisure battery was about 75% charged.  I included this experiment as part of the journey so I purposely didn't charge the leisure battery.

The van's alternator took a distance of 250 miles (5 hours traveling time) to virtually fully charge that leisure battery. On the way home it was still pushing a trickle charge into it. 

So a split charge relay or voltage sensing relay is not the most useful thing we could own for charging our leisure battery on the move. However, it has justified itself on a few occasions. With the engine idling the two of us were able to finish a job that was a fair distance away when our first leisure battery failed.

I have an Airtronic diesel heater in the van. When its cold I switch it on to keep the cab warm. Because this takes a fair chunk of power to start it, I always leave the engine running so the alternator provides the power rather than my leisure battery.

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[Dave Willis]

Gold, does the iload only have one battery?

[Dave Willis]

Spruce, how come my Hiace batteries have never gone flat?
It's got twin batteries under the bonnet I run a live off one, work all day and only travel five miles max. I never charge them and they are original batteries from 2007 might be 2006 (i'd have to check). How on earth does it work?

[nathankaye]

I switched just over a yr ago to wfp from trad. I use a 110a battery. I used to fetch it in once a week maybe twice to charge it over night. Never bothered with a split relay as i dont travel a great distance. After a couple of months, stuck a solar panal on top of roof and i have never looked back. On a slightly dull day, if my amp starts droping to 12.7 i stick my smaller solar panal on top as an added boost. Never been caught short, ie had to run engine (using fuel cost) to continue to work!! Its getting a steady stream charge whilst im working or parked eating.
Thats also working thru winter and the darker cloudier days as well.

[Spruce]

Spruce, how come my Hiace batteries have never gone flat?
It's got twin batteries under the bonnet I run a live off one, work all day and only travel five miles max. I never charge them and they are original batteries from 2007 might be 2006 (i'd have to check). How on earth does it work?

Dave, I have no idea tbh.

When I first built my sons van in 2007,  I not only fitted a 85amph leisure to power his pump, I also fitted a change over switch so he could draw from the van's starter battery if his leisure battery went flat.

I fitted the change over switch on the side of the passenger seat as the leisure battery fitted nicely under the passenger seat. In those days my son took his Jack Russell to work with him. She's an absolute nightmare and still is. In her efforts to attack passing dogs she knocked the switch over so the pump was drawing from the van battery. unbeknown to us.

It didn't dawn on me why the leisure battery was fully charged when I put the charger onto it. By the end of the 4th day the vans starter battery was completely flat and son bump started it on the hill he was parked on.
We charged that battery up and didn't have another issue for about a year before the starter battery failed. We replaced it and a few days later, Poppy did the same thing and again that battery was flat by the end of the 4th day.

The van's alternator was tested and we let the alternator recharge the battery this time. Everything checked out.

At the same time their was a chap on here by the name of Tim?? who also had a Citroen Berlingo. We had the Peugeot Partner which is the same van. He used the van battery as a power source without any problems.

When son in law joined us nearly 5 years ago now, he got a Ford Transit Connect T220 LWB. We tried to run his pump off the van battery but we experienced the same issue we did with the Peugeot. SIL was doing a higher mileage than we were but he couldn't get it to work.
However, there is a twist to this as the controller we fitted to SIL's system was the latest Varistream that consumed power even when the unit was switched off as it has a battery monitor. We discovered this when he was away for a week and his van was left parked on the driveway. A fully charged 85amph battery lost 1/2 its charge during that week. Swapping batteries for one that remained fully charged for a week helped us to find and solve the problem. I had by then fitted a leisure battery and an on/off isolator switch to switch the Varistream off. That solved the battery drain problem but we never went back to using the starter battery as a power source as the leisure battery did the job.

Apparently one of Dave Kent's vans also runs of the starter battery with no issues and that van does less mileage than ours.

Why? I don't know.

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[Spruce]

I switched just over a yr ago to wfp from trad. I use a 110a battery. I used to fetch it in once a week maybe twice to charge it over night. Never bothered with a split relay as i dont travel a great distance. After a couple of months, stuck a solar panal on top of roof and i have never looked back. On a slightly dull day, if my amp starts droping to 12.7 i stick my smaller solar panal on top as an added boost. Never been caught short, ie had to run engine (using fuel cost) to continue to work!! Its getting a steady stream charge whilst im working or parked eating.
Thats also working thru winter and the darker cloudier days as well.

Do you mean 12.7 volts?

I've had my eye on this for a while

http://www.ebay.co.uk/itm/281638601362?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

Its a big panel but in perfect conditions it is rated at 100 watt which is just over 8 amps. The motorhome guys recon these panels are useless in the UK winter. I took their word for it and never bought one. (Actually I was going to purchase an Mppt controller but their are so many Chinese fakes on Ebay. A UK made MPPT controller costs as much as the solar panel.)

It would be good to see a picture.

Mark Munro also got a panel set like this Ebay one but it didn't work for him.

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[AuRavelling79]

Gold, does the iload only have one battery?

Yes. I have put another behind the bulkhead.

[nathankaye]

If i remember, ill post a couple of shots tomorrow.

[nathankaye]

The smaller panal i only fetch out if required. The larger panal is fixed. (Im aware it should have a slight elevation, but its not caused any problems charging.



I also should have used a controller box but never got round to it. If/when this battery dies, i will sort it then. When i start to use the battery, obviously the voktage reading on digi controller will go down, but i certainly wont require the smaller panal today.

[Tom White]

I just use brute strength and ignorance and lug my battery into the shed to charge after I finish work, then lug it back out to the van in the morning.

Sometimes, for strength training, I'll get 2 x 25 litre barrels and do 'Farmer's Walks' up and down our street too.

It helps keeps the neighbour's from talking to me.

[nathankaye]

Cant beat free electricity though.
Still toying with idea of setting up a solar panal in garden to trickle charge a 12v battery in shed and run ny booster pump on RO from it instead. Do my part for environment and long term save on electric bill...

[Spruce]

The smaller panal i only fetch out if required. The larger panal is fixed. (Im aware it should have a slight elevation, but its not caused any problems charging.



I also should have used a controller box but never got round to it. If/when this battery dies, i will sort it then. When i start to use the battery, obviously the voktage reading on digi controller will go down, but i certainly wont require the smaller panal today.

Thanks.

I see that the voltage is 16 which means that the panel is pushing out 1.3 amps charge into the battery.

The figures are interesting.

In a 10 hour day of sunshine in the summer your panel should be charging your battery by 13 amps. If on the same day your pump draws 4 hours at 4.5 amps you are short by 5 amps. Over a 5 day week thats 25 amps. So your 110 amp h battery will be about 75% charged. If you didn't work Saturday and Sunday you should be just back to a full charge Sunday evening.

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[nathankaye]

I dont disconnect the panal from the battery and the cable is one way (so the panal isnt draining any charge from the battery) so even when im parked or finished for the day, the battery is charging nicely.  But then if there is little direct sunlight, i pop out the small panal.
Its serves my purposes nicely.
Hope it helps

[AuRavelling79]

I dont disconnect the panal from the battery and the cable is one way (so the panal isnt draining any charge from the battery) so even when im parked or finished for the day, the battery is charging nicely.  But then if there is little direct sunlight, i pop out the small panal.
Its serves my purposes nicely.
Hope it helps

It does help. Thanks.