Leisure Battery System & General Electrics

[KieranC]

Hi folks,

So I’m at the stage of figuring out how to power and wire my 1999 transit van… Unfortunately I am a complete novice in this area and help would be much appreciated!!

I’ve calculated my power usage (W/V=A) and decided that 2x 125ah batteries would give me sufficient power to last at least 3/4 days at maximum usage.

The main aim of the system will be to power 6x led lights, phone & laptop chargers, refrigerator ignition (run on gas) and occasionally other higher wattage appliances such as an electric blanket or a sound system. I also have a 600w inverter should I need to run any 240v appliances. To allow me to use/charge multiple items at once I plan to fit two 12v 3-way splitters and have a 4-way splitter for my inverter.

I aim to charge the batteries using a voltage sensitive relay, which as I understand connects via one wire to my engine battery and then via a second to my leisure batteries.

My alternator creates 95A per hour, although the way I understand it this is dependent on the van running at something like 60mph and would create considerably less should the van simply be left ticking over at 0mph. Also I understand that the age of the vehicle suggests that its efficiency will have dropped.

I am considering buying a battery to battery charger which claims it can up the charge by 5x. So assuming my van creates 25A when ticking over it would take 5hrs to recharge by 125A WITHOUT this charger but only 1hr WITH it. Sounds worthwhile?

I understand that wiring a voltmeter into the system will tell me how much power is remaining in my batteries and that it would be good to fit a fuse box and a residual current device to protect the batteries from electrical damage and to stop a single appliance tripping the whole system.

And lastly I understand that I need to buy different types and sizes of wire depending on the amount of current that will be running through them so as not to burn them out or to cause inefficiency and earthing everything is essential.
Questions:
Basically does this sound like I’ve covered everything? Is there anything else I should definitely be buying? Do you have any advice regarding the fitting wiring of any of the above?
And more particularly..
1) Will I be able to fit these items myself? (Having it checked by an electrician afterwards..)
2) What AH voltage sensitive relay would be advisable?
3) I’ve found voltmeters online that range in price from £10-100, would a cheaper one suffice? Could you recommend any?
4) Am I right in thinking that all my appliances will run to my fuse box, which is then connected by one wire to the leisure batteries?
5) If I fit a mains hook-up how can I switch my circuit so that it is powered by the mains and not by the leisure batteries?
6)What is a realistic estimate for the amount of power that my alternator will generate whilst ticking over?

Haha sorry for the length of my questioning as you can tell I’m fairly clueless and I figured I’d have to be thorough… Any advice will genuinely be greatly appreciated !!

Thanks, K.

[Darren]

Hi
Hi

Sounds like you’ve done some good research and good a good handle on the situation.

2 leisure batteries sounds like a good idea.
The alternator system is designed to charge the engine battery slowly, and tentatively, in that it will never over-charge it.
This isn’t ideal for charging leisure batteries, but does work, especially if you don’t use the leisure batteries a lot between drives. It works fine for most people.

A battery to battery charger will charge the leisure batteries more quickly. But this is only worth it if you won’t drive the vehicle much between camping usage. If you will drive the vehicle more then 3 hours between camping trips you probably don’t need the battery to battery charger, a split charge relay from the engine battery will probably be fine. If you are fitting a mains charger you can always top-up the batteries when at home/on hookup.

Use 10mm cable between the batteries. Use an inline megafuse between the batteries also.

In answer to your questions

1. Yes. Most are fairly easy to fit. Take your time with it.
2. This is the best one that I know of, much better quality than others: http://www.iem-services.co.uk/showdetails.asp?id=1170
3. A cheap one will be fine.
4. Yes, perfect setup. Connect the 2 leisure batteries together. Then run the fusebox to one of the leisure batteries.
5. The best option is to wire the mains battery charger to one of the leisure batteries. When the charger is on it will provide 14.4 volts to the batteries, and also all of the appliances via the fuse box. This is the best method, and exactly what the engine would be doing if running. 14.4 volts is standard for a charging 12 volt system. No need to switch between anything.
6. Almost none. The engine needs to be revving/driving to charge. 3+ hours is probably enough to mostly charge the batteries.

I have used this setup (3 x leisure batteries) for 4 years now. Even lived in the van for a year.

Hope this helps, ask any more questions you have.

[Darren]

Hi
Hi

Sounds like you’ve done some good research and good a good handle on the situation.

2 leisure batteries sounds like a good idea.
The alternator system is designed to charge the engine battery slowly, and tentatively, in that it will never over-charge it.
This isn’t ideal for charging leisure batteries, but does work, especially if you don’t use the leisure batteries a lot between drives. It works fine for most people.

A battery to battery charger will charge the leisure batteries more quickly. But this is only worth it if you won’t drive the vehicle much between camping usage. If you will drive the vehicle more then 3 hours between camping trips you probably don’t need the battery to battery charger, a split charge relay from the engine battery will probably be fine. If you are fitting a mains charger you can always top-up the batteries when at home/on hookup.

Use 10mm cable between the batteries. Use an inline megafuse between the batteries also.

In answer to your questions

1. Yes. Most are fairly easy to fit. Take your time with it.
2. This is the best one that I know of, much better quality than others: http://www.iem-services.co.uk/showdetails.asp?id=1170
3. A cheap one will be fine.
4. Yes, perfect setup. Connect the 2 leisure batteries together. Then run the fusebox to one of the leisure batteries.
5. The best option is to wire the mains battery charger to one of the leisure batteries. When the charger is on it will provide 14.4 volts to the batteries, and also all of the appliances via the fuse box. This is the best method, and exactly what the engine would be doing if running. 14.4 volts is standard for a charging 12 volt system. No need to switch between anything.
6. Almost none. The engine needs to be revving/driving to charge. 3+ hours is probably enough to mostly charge the batteries.

I have used this setup (3 x leisure batteries) for 4 years now. Even lived in the van for a year.

Hope this helps, ask any more questions you have.

[KieranC]

Thanks Darren that’s a
Thanks Darren that’s a brilliant reply.

I’m just doing some more research before I go ahead and buy any of the components.

I’ve found pretty much all of the components but I do have a few more questions…

If I buy a Sterling Power Battery to Battery 12v-12v 100A would I not need a relay? I’m probably wrong but I get the impression the charger incorporates the relay function?
http://www.sp-shop.co.uk/Battery-to-Battery-Chargers/

Then I’m a bit stumped with the fuse box, I think having 8/10 ways would be good. Although I say that mainly because I’m not sure if the sound system I want to fit will need more than one way (sub & 4x speakers) so I’d be allowing for this plus one or two spare with a 10way box. Should I be looking at buying a consumer unit? Something like this?
http://www.screwfix.com/p/mk-sentry-16-module-10-way-dual-rcd-consumer-unit-with-8-mcbs/40025

And lastly I’m not sure how I will connect a mains hook-up cable to my mains battery charger. Do I need some kind of adapter?
http://www.ctekchargers.co.uk/ctek-mxs-25.php

Thanks again Darren, your advice is a great help!

[KieranC]

Thanks Darren that’s a
Thanks Darren that’s a brilliant reply.

I’m just doing some more research before I go ahead and buy any of the components.

I’ve found pretty much all of the components but I do have a few more questions…

If I buy a Sterling Power Battery to Battery 12v-12v 100A would I not need a relay? I’m probably wrong but I get the impression the charger incorporates the relay function?
http://www.sp-shop.co.uk/Battery-to-Battery-Chargers/

Then I’m a bit stumped with the fuse box, I think having 8/10 ways would be good. Although I say that mainly because I’m not sure if the sound system I want to fit will need more than one way (sub & 4x speakers) so I’d be allowing for this plus one or two spare with a 10way box. Should I be looking at buying a consumer unit? Something like this?
http://www.screwfix.com/p/mk-sentry-16-module-10-way-dual-rcd-consumer-unit-with-8-mcbs/40025

And lastly I’m not sure how I will connect a mains hook-up cable to my mains battery charger. Do I need some kind of adapter?
http://www.ctekchargers.co.uk/ctek-mxs-25.php

Thanks again Darren, your advice is a great help!

[Darren]

Hi Kieran
Hi Kieran

Yes, you don’t need a relay with a the Sterling Batter to Battery charger.

You can always add another fuse box if you run out of fuse positions. But it’s good to plan to leave a few spare.

I would go for a smaller consumer unit. You can wire everything into two circuits normally (high power/low power).
This one is fine and smaller:
http://www.screwfix.com/p/mk-sentry-4-way-rcd-garage-consumer-unit/33248

For the battery charger I cut the 240 v plug off mine wired it straight into the consumer unit. The hookup goes straight into the consumer unit. So as soon as you plug into the hookup supply the battery charger has power.

[Darren]

Hi Kieran
Hi Kieran

Yes, you don’t need a relay with a the Sterling Batter to Battery charger.

You can always add another fuse box if you run out of fuse positions. But it’s good to plan to leave a few spare.

I would go for a smaller consumer unit. You can wire everything into two circuits normally (high power/low power).
This one is fine and smaller:
http://www.screwfix.com/p/mk-sentry-4-way-rcd-garage-consumer-unit/33248

For the battery charger I cut the 240 v plug off mine wired it straight into the consumer unit. The hookup goes straight into the consumer unit. So as soon as you plug into the hookup supply the battery charger has power.

[KieranC]

Hi Darren, I think I may have
Hi Darren, I think I may have confused us both a tad.

I plan to only have a 12v circuit in my van and will only use the mains hook-up to charge my batteries. In this situation would I actually need a consumer unit? I think maybe what I’m looking for is a blade fuse box where I can wire each item in the circuit to this with an individual fuse?

Sorry I’m pretty stumped at this stage!

[KieranC]

Hi Darren, I think I may have
Hi Darren, I think I may have confused us both a tad.

I plan to only have a 12v circuit in my van and will only use the mains hook-up to charge my batteries. In this situation would I actually need a consumer unit? I think maybe what I’m looking for is a blade fuse box where I can wire each item in the circuit to this with an individual fuse?

Sorry I’m pretty stumped at this stage!

[Darren]

Hi Kieran
Hi Kieran

If you will use the mains only to charge batteries you could just fit a single plug socket inside the van, from the hookup.
Then plug the battery charger into that.

If you want to add more than one circuit to the mains hookup (i.e. something other than the battery charger) you will need a consumer unit, as this is the only safe way of adding multiple mains circuits to a single hookup supply.

[Darren]

Hi Kieran
Hi Kieran

If you will use the mains only to charge batteries you could just fit a single plug socket inside the van, from the hookup.
Then plug the battery charger into that.

If you want to add more than one circuit to the mains hookup (i.e. something other than the battery charger) you will need a consumer unit, as this is the only safe way of adding multiple mains circuits to a single hookup supply.

[Anonymous]

Hi Darren,
Hi Darren,

Could I simply use a mains supply unit when on site? And plug the charger into that?
http://www.amazon.co.uk/Camping-Site-Mains-Supply-Unit/dp/B001DJ8E9Q/ref=sr_1_1?s=sports&ie=UTF8&qid=1399666748&sr=1-1&keywords=camping+mains+supply+unit

If I then run everything (lights, 12v chargers, inverter etc) via the leisure batteries would that count as adding another mains circuit?

[Anonymous]

Hi Darren,
Hi Darren,

Could I simply use a mains supply unit when on site? And plug the charger into that?
http://www.amazon.co.uk/Camping-Site-Mains-Supply-Unit/dp/B001DJ8E9Q/ref=sr_1_1?s=sports&ie=UTF8&qid=1399666748&sr=1-1&keywords=camping+mains+supply+unit

If I then run everything (lights, 12v chargers, inverter etc) via the leisure batteries would that count as adding another mains circuit?

[Darren]

Yes, you could simply use the
Yes, you could simply use the supply unit in your link, with the charger plugged in. That would be fine.

[Darren]

Yes, you could simply use the
Yes, you could simply use the supply unit in your link, with the charger plugged in. That would be fine.

[Author]

Posts