Split Charge Kit - Car thread - Help please

binge · Emo Kiddy Joined: 03 Jul 2004 Karma :

Hello guys,

After a little 'how to' if you like, regarding split chargers.

I'm in the process of getting my van up and running, and putting into place the final bits and pieces of getting it ready to be a work van.

In the back of the van, I am going to be needing 240v supply, to my compressor, and to some of my power tool chargers (Battery impact gun in particular as it's over 12v).

Im just looking at split charge systems on ebay, and they are all different.

I've notices some at 100£ plus, and others at a £19.99 buy it now etc.

The expensive ones just look like a stereo amp.
The cheaper ones consist of a Splitter relay, wiring, fuses etc.

Reading through the descriptions, I'm trying to get an idea of what is going to work for me.

Can anybody tell me if this is the best setup or not?

Front end of van, engine electrics, starter motor etc, all running off original battery. Not touching that.

Now second battery, will be behind passenger seat. I want this to run the power inverter.

Now the split charge relay, I gather from the descriptions, literally hooks up the two + terminals on the two batteries. Length of high gauge wire, fuses, and the split charge relay.

Then I am guessing, I have to earth the second battery to the body of the car.

At this point, both batteries are hooked up to the alternator, but the second battery, is on an auto 'switch', which isolates it from the main battery, and alternator of the car at certain times.

So now I have a battery in the back of the car, which I want to run my power inverter straight from.

What I need to know, is what is stopping this from just draining the juice from my main battery too?

As surely, the switch relay will make a circuit, whenever there is a current draw from the second battery? As it's not going to be making it's full 12v when there is a load on it.

How exactly will it work?

Cheers,

Ben
____________________
- Honda XL125S - CBR400 NC29 - VFR400 NC30 - CBR400 NC29 - TL1000R - TeeZeR Pit! - Bandit 12 - YZF450 - LuckyMX125 Pit! - Demon X XLR 140 Pit!
- Stomp KZ 160 Pit! - Demon X D-link 140 Pit! - CRF50F Mini-Pit - MonsterMoto 155cc MiniSM - Honda Chaly 150cc - Yamaha 98' R1
- Honda Chaly 140cc - Thumpstar 190cc 4v MiniSM - Aprilia RS125 Pit-Bike -

69chris · Trackday Trickster Joined: 10 May 2011 Karma :

the relay only flows one way so your 2nd battery will charge as normal when the engine is running but power wont flow 'the other way' when the engine is off........... at least thats how it worked when i used a split charge set up on my camper Thumbs Up

binge · Emo Kiddy Joined: 03 Jul 2004 Karma :

Okay I see.... Kinda.

Although if it was fitted with a diode, and the power can flow from the alternator/main battery, to the second battery. Surely that would mean that the second battery would be the 'safe' one, which cant be drained from say, the headlights been left on?

Little side note also. My compressor, It's not massively big, just a Clarke 30L jobby, 10 bar working pressure, 2.5hp unit.
What sort of inverter would I need to run it up?
Been looking online, a lot of the yanks seem to think they take around 250/300 watts of working power, but a 2.5 to 3 times that, to actually get the pump 'started'.

Would I be safe to say a 1000w inverter would be enough? Or would I need something huge, like 2000w - 3000w?

Reason I ask, is because the latter type, is about £300. Laughing

____________________
- Honda XL125S - CBR400 NC29 - VFR400 NC30 - CBR400 NC29 - TL1000R - TeeZeR Pit! - Bandit 12 - YZF450 - LuckyMX125 Pit! - Demon X XLR 140 Pit!
- Stomp KZ 160 Pit! - Demon X D-link 140 Pit! - CRF50F Mini-Pit - MonsterMoto 155cc MiniSM - Honda Chaly 150cc - Yamaha 98' R1
- Honda Chaly 140cc - Thumpstar 190cc 4v MiniSM - Aprilia RS125 Pit-Bike -

sickpup · Old Timer Joined: 21 Apr 2004 Karma :

Honest truth, buy a small generator. Well that or a 24V land rover with a 90amp generator.

binge · Emo Kiddy Joined: 03 Jul 2004 Karma :

I did consider that, but it's more room, and weight in the van. Plus, something else to maintain and put fuel in.

Plus, I still, dont know what sort of wattage I need to run my compressor.

I have been reading up on modified A/C pumps (I'd need to make one fit my engine first anyway, but easily done with the Laguna bracket and belt), to pump air into a tank. They can produce around 200psi of pressure, and with a flowblack valve, and a pressure blow-off valve/switch, can be done.
Then just a small inverter to run my battery charger for my nut gun?....

But then that's an engine out job agian. Thinking

Are power inverters really that bad?

All the mobile tyre vans and stuff seem to use them, and run tyre changers on them.
____________________
- Honda XL125S - CBR400 NC29 - VFR400 NC30 - CBR400 NC29 - TL1000R - TeeZeR Pit! - Bandit 12 - YZF450 - LuckyMX125 Pit! - Demon X XLR 140 Pit!
- Stomp KZ 160 Pit! - Demon X D-link 140 Pit! - CRF50F Mini-Pit - MonsterMoto 155cc MiniSM - Honda Chaly 150cc - Yamaha 98' R1
- Honda Chaly 140cc - Thumpstar 190cc 4v MiniSM - Aprilia RS125 Pit-Bike -

ZebraDriver · Scooby Slapper Joined: 13 Feb 2011 Karma :

A 2.5 HP compressor will draw around 2000 watts once it has got over the "hump" of starting the motor. To supply the invertor you will need around 185 amps at 12 volts (assuming 90% efficiency for the invertor). A battery will not be able to supply this for more than a couple of minutes before the voltage drops to a point where the invertor will shut down, and thats before you consider the start current for the motor.

Probably better to look at some form of engine driven compressor.

ZD

hmmmnz · Super Spammer Joined: 22 Aug 2006 Karma :

ive just done the split charge thing on 2 vans (the mrs has had her little brother and step father come over to new zealand both bough vans to see nz in)

i used a 140a voltage sensitive relay on both, like this
when the car is running it starts charging the house battery, when the voltage drops below 13v on the main battery, it seperates the house from the main battery,

i also have installed inverters in both,
a modified sine wave in one and a pure in the other,

a modified does most things and are cheap,
the pure sinewave ones will run any thing but are expensive,

bear in mind, that a modified won't run any synchronized AC motors (brushless etc) and with normal ac motors the modifined sine wave is hard on the windings and heats them up,

so to run an ac motor via an inverter a pure sine wave inverter is your only real option,

failing that, a dc motor, you can get some fairly decent 12/24volt compressors these days
____________________
the humans are dead
I kick arse for the lord
Wiring Diagrams BIDNIP it bitches

sickpup · Old Timer Joined: 21 Apr 2004 Karma :

binge · Emo Kiddy Joined: 03 Jul 2004 Karma :

I havent under evaluated anything. I dont want to have to be running a petrol/derv genny all day.
Im considering the modded air con compressor plumbed up to a big tank with a blowback valve and pressure regulator switch hooked up to the clutch on the compressor pulley. I just need to find out what volumes of air it can run in a set period of time. I have battery powered imact tools so only really need the compressor for brake bleeder and air tap for tyres etc.
But i still want it to be more useful than a cig lighter tyre inflator jobby.
____________________
- Honda XL125S - CBR400 NC29 - VFR400 NC30 - CBR400 NC29 - TL1000R - TeeZeR Pit! - Bandit 12 - YZF450 - LuckyMX125 Pit! - Demon X XLR 140 Pit!
- Stomp KZ 160 Pit! - Demon X D-link 140 Pit! - CRF50F Mini-Pit - MonsterMoto 155cc MiniSM - Honda Chaly 150cc - Yamaha 98' R1
- Honda Chaly 140cc - Thumpstar 190cc 4v MiniSM - Aprilia RS125 Pit-Bike -

jimspeed · World Chat Champion Joined: 05 Mar 2010 Karma :

I used to run a 2KW inverter in my rally van, spilt charge relay which only connects the both batteries at 13v and 2 massive batteries from a CAT bulldozer,(12v but jumped together to give more AH) these would run the inverter running tv etc for about 3 days as a camper but took ages to recharge, we could run a big grinder off it and even a 800w water heater but not for too long, my 2.5 hp compressor wouldn't run off my 3.5kw genny unless you let ALL the air out of it first.
personally I cant see you having enough battery power to do without maybe 3 big leasure batteries and even then wouldn't have a big enough altenator to charge em.
small genny or an engine driven pump is the answer, or you can sometimes find petrol powered compressors.
____________________
Hyosung cruise 125(passed test on, sold) Kawasaki el 252 (better than expected but sold on) Kawasaki GPZ500S first "big"bike.(sold) ZZR600 E5..Z750 2007,ER5, currently on a 2008 Enfield bullet electra x and loving it..
,"Alpha-9: Is there any correlation between dyno rod and dyno kits?"

J4mes · World Chat Champion Joined: 18 Mar 2011 Karma :

I know a fair few people who use the T-Maxx split charge systems which can be had for about £80 off ebay, it charges them both at the same time but isolates them when they are discharging, and you can manually link both the batteries together for high load situations, such as running a winch, or possibly a compressor.

Lots of information on this unit and others on the many 4x4 forums around Thumbs Up

binge · Emo Kiddy Joined: 03 Jul 2004 Karma :

Some interesting input. Cheers guys.

It's really been on my mind all day, different methods of making, and storing compressed air while on the go, without 240v hook up.

I'm really drawn towards the A/C converted pump, driven from the alternator belt. Only downside is that the engine may as well come back out, or at least drop it right down, to get access to that area of the engine to fit and make brackets etc.

There seem to be loads of people online running compressors from 240v inverters though. Which baffles me. One guy is running his actual house from 2 car batteries and a 5kw inverter. Shocked

He just says he cant run the fluro light in his sons room. Everything else is fine. So strange!

Uprating my alternator isnt an issue, I can happily do that. There is probably even room there go get a second alternator on. And I also have another Renault alternator spare...
But if I go to that extent, I'd rather just convert an A/C pump.

Electric wise, I only need 240v for a compressor, and for my 1/2 SnapOn impact gun, as it's 18v. Not something that will charge from a 12v car battery. The rest of my electrical gear, like LED lights, under bonnet lights, even my 3/8 impact gun, are all under 12v, so can easily be run through a ciggy lighter extension on their individual chargers (Most have in car charging leads, I'd need to make something up for the Dewalt 3/8 gun).

So I could probably get away with not even having a big inverter, and just running a decent 12v setup in the back for all my tools. I'd get away with a ciggy lighter plug in inverter for the snapon 18v charger I should think. As long as I make sure the gauge on the wiring is good enough.

I shall keep researching...

Ben
____________________
- Honda XL125S - CBR400 NC29 - VFR400 NC30 - CBR400 NC29 - TL1000R - TeeZeR Pit! - Bandit 12 - YZF450 - LuckyMX125 Pit! - Demon X XLR 140 Pit!
- Stomp KZ 160 Pit! - Demon X D-link 140 Pit! - CRF50F Mini-Pit - MonsterMoto 155cc MiniSM - Honda Chaly 150cc - Yamaha 98' R1
- Honda Chaly 140cc - Thumpstar 190cc 4v MiniSM - Aprilia RS125 Pit-Bike -

binge · Emo Kiddy Joined: 03 Jul 2004 Karma :

Little update on my finds.

I've just read a project thread on a guy who has done something similar in a jeep wrangler.
He's run an AC compressor, some other bits and pieces, and a tank, to pretty much run all his air tools, air guns, air ratchets etc. He says it runs fine too, which is promising.

The only thing I have, is all the Renaults with the 1.9 F8Q engine (Like mine) which ran Air con, also ran electric power steering, so the AC pump went in place of the PAS pump on the original engine.

I have plenty of room to mount an AC compressor up at the top.

The compressor I would use would be the same Renault item, for ease of mounting lugs:

https://i.ebayimg.com/t/RENAULT-MEGANE-SCENIC-RX4-1-9-DCI-A-C-PUMP-AIR-CON-PUMP-COMPRESSOR-2002-MODEL-/00/s/MTIwMFgxNjAw/$T2eC16F,!zcE9s4g0u7yBQipMsSgmQ~~60_58.JPG

I would mount it above the alternator, on a bracket which bolts under the two 13mm hex bolts you can see on the big bracket:

https://sphotos-d.ak.fbcdn.net/hphotos-ak-snc6/251725_10151165231105606_1322136521_n.jpg

As you can see, Tons of room to get it there:

https://sphotos-b.ak.fbcdn.net/hphotos-ak-ash4/227936_10151172885630606_1805330659_n.jpg

I can then mount the airlube and intake etc, behind that driver side headlight. And then run a line down the offside sill of the car, and into the tank, which I will bolt to the underside of the van, where my spare wheel would be.

Air line connections will come up through the bed of the van, in one of the back corners.

Hopefully this should work. Razz

____________________
- Honda XL125S - CBR400 NC29 - VFR400 NC30 - CBR400 NC29 - TL1000R - TeeZeR Pit! - Bandit 12 - YZF450 - LuckyMX125 Pit! - Demon X XLR 140 Pit!
- Stomp KZ 160 Pit! - Demon X D-link 140 Pit! - CRF50F Mini-Pit - MonsterMoto 155cc MiniSM - Honda Chaly 150cc - Yamaha 98' R1
- Honda Chaly 140cc - Thumpstar 190cc 4v MiniSM - Aprilia RS125 Pit-Bike -

jimspeed · World Chat Champion Joined: 05 Mar 2010 Karma :

how much flow do you need?
In my trials car I run a 12v rangerover air suspension pump which fills a 12kg gas bottle to inflate the tyres.
or what about a lorry air compressor?
____________________
Hyosung cruise 125(passed test on, sold) Kawasaki el 252 (better than expected but sold on) Kawasaki GPZ500S first "big"bike.(sold) ZZR600 E5..Z750 2007,ER5, currently on a 2008 Enfield bullet electra x and loving it..
,"Alpha-9: Is there any correlation between dyno rod and dyno kits?"

binge · Emo Kiddy Joined: 03 Jul 2004 Karma :

Well it needs to be able to fill a 25/30L tank up to over 100PSI (Ideally) in around a minute or so?
Never thought of a lorry compressor. Not even looked into it.
____________________
- Honda XL125S - CBR400 NC29 - VFR400 NC30 - CBR400 NC29 - TL1000R - TeeZeR Pit! - Bandit 12 - YZF450 - LuckyMX125 Pit! - Demon X XLR 140 Pit!
- Stomp KZ 160 Pit! - Demon X D-link 140 Pit! - CRF50F Mini-Pit - MonsterMoto 155cc MiniSM - Honda Chaly 150cc - Yamaha 98' R1
- Honda Chaly 140cc - Thumpstar 190cc 4v MiniSM - Aprilia RS125 Pit-Bike -

jimspeed · World Chat Champion Joined: 05 Mar 2010 Karma :

https://www.ebay.co.uk/itm/PTO-Driven-Compressor-NEW-/271024408387?pt=UK_BOI_FarmingEquipment_RL&hash=item3f1a504743&_uhb=1
no oiler needed etc then I believe but you would need to make a drive for it somehow?
plenty of cfm there too
____________________
Hyosung cruise 125(passed test on, sold) Kawasaki el 252 (better than expected but sold on) Kawasaki GPZ500S first "big"bike.(sold) ZZR600 E5..Z750 2007,ER5, currently on a 2008 Enfield bullet electra x and loving it..
,"Alpha-9: Is there any correlation between dyno rod and dyno kits?"

binge · Emo Kiddy Joined: 03 Jul 2004 Karma :

Does look pretty good, but I have no realistic way of making a drive for it, without the van moving.
Certainly something to consider though. Wonder how much drive it actually needs, and how hard it would be to turn.
____________________
- Honda XL125S - CBR400 NC29 - VFR400 NC30 - CBR400 NC29 - TL1000R - TeeZeR Pit! - Bandit 12 - YZF450 - LuckyMX125 Pit! - Demon X XLR 140 Pit!
- Stomp KZ 160 Pit! - Demon X D-link 140 Pit! - CRF50F Mini-Pit - MonsterMoto 155cc MiniSM - Honda Chaly 150cc - Yamaha 98' R1
- Honda Chaly 140cc - Thumpstar 190cc 4v MiniSM - Aprilia RS125 Pit-Bike -

stevo as b4 · World Chat Champion Joined: 17 Jul 2003 Karma :

On our truck at work we have a PTO driven compressor and alternator. The PTO input comes off the gearbox input shaft. The engine which is a 4.5L turbo diesel runs at 1200rpm with the PTO engaged and has some kind of governor to increase throttle under load to maintain 1200rpm.

Id think the PTO driven lorry compressor is a bit of a fail unfortunately for a car derived van project. There is no place to mount it. Your air con compressor idea sounds more feasible, or maybe as an alternative a small engine driven piston compressor similar in size to the vacuum pump from a diesel van engine might do to job?

I do think that running a second heavy duty leisure battery with a split charge system is a good idea for most small current drawing tools etc, but having a decent air receiver in the back charged by a small petrol or diesel driven compressor is the best solution.

You can get some generator's now with interchangeable drives that couple up to either a compressor, generator or jet washer pump, and making up something similar yourself, would probably be more versatile that just a 2kw generator or engine driven compressor.