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WoffoDave
5th October 2011, 05:43 PM
Team, might sound basic but "what electrics am I running?"

I have a 91 SWB Safari TD42.
The dash electrics show a 24v dial
I have 2 bty in the bay
The engine bay fuzes are 24v
Sooooo... I think I am running 24v, only...

The lighter socket hasn't blown up the GPS or phone charger and the towbar electrics haven't blown up the trailer lights (brought for a car not the mantruck)

Where do I start?

D.

Finly Owner
5th October 2011, 09:33 PM
OK my guess is you sound 99% sure to have 24v. Most GPS & phones tollerate 24v these days, although i don't like pushing my luck with that sort of technology.



Tim

WoffoDave
6th October 2011, 04:32 PM
Thanks Tim, current update:
had a good look under the hood (2 bty and 24v) and inside (24v fittings).
Volt tested the cig lighter (24v) and towing electrics (24v) so there you go.

Closer look at the phone chager: 12v/24v on the side so guess why that didn't blow...
Not sure about the trailer, need to check the actual trailer lights next.

Who knows about the GPS, hopefully the same 12v/24v charger.

Soooo, guess I need to be careful about running a fridge from the main bty circuit then...

patch697
6th October 2011, 05:35 PM
You can get a reducer or you can bring 12 volts in from under the bonnet even with a 24 volt system.

Just be sure to run a fusible link inline with the incoming power cable (have this close to the battery) & an after market fuse box for your 12v accessories (can be brought almost anywhere)

This way you can run both 12v & 24v compatible accessories.

Yendor
6th October 2011, 06:07 PM
I recommend that you never connect 12 volt accessories across one battery in a 24 volt system.

You will find doing this can cause starting problems and shorten the life of the batteries.

You should always use a voltage reducer.

With the fridge you may need to look at purchasing one that will run on 24 volts.

The other option you have is fitting a second 12 volt alternator and another battery to run your 12 volt accessories.

WoffoDave
8th October 2011, 06:24 AM
Thanks guys.
I need to have a look for the factory reducer, I think there is 1 for the radio.

Will look at setting up another cigarette point in the centre rear console at some stage, need to save my pennies for tires/rims and suspension 1st.

DT

patch697
8th October 2011, 09:34 AM
Reducers come in different amperage ratings so be sure to get one that suites your needs. (head units only drew up to around 10 amps so you may find it under rated for bigger accessories)

Fridges have a large amp drew on start up so look at this as being your base minimum.

I have hooked up 12v systems in 24v rigs using both methods mentioned above & have not had a issue (I've mostly used reducers though) but im happy stand corrected with sourcing the 12v direct from the battery & I will be following Yendor's advice in the future.... Thanks Rod.

WoffoDave
8th October 2011, 10:33 AM
THanks all, some sage advice here (learnt the hard way me thinks???)

I'll let you know how it goes.
Dave

Yendor
9th October 2011, 01:33 PM
Paul, I was not having a go at you mate and I did not mean any disrespect.

I will have to try harder with the wording in my posts.

If it was my truck I would not connect a 12 volt accessory to one battery.

But I understand the cost involved with purchasing reducers, so if someone asked me to wire up their truck in this way I would (I would advise them not to) but it is their truck.

If you do decide to wire it up this way, you could try periodically swapping the batteries from drivers side to passengers side every month or so.

You will also need to make sure you connect the accessory to the correct battery, it is the one where the negative post is connected to the body/block.

Rodney

philfree
9th October 2011, 05:13 PM
Hi
New here but have some input Yendor is correct what happnes is when you draw off of the 12v battery it requires more to recharge and because they are charged in a 24v bank the 24v battery gets overcharged and boiled damageing the battery and the 12v gets flattned causeing these issues. as said above you can run a reducer whitch is what a bus company did with the 12 computer on a 24v bus this works quite well for small things radios and phone charges but as the bus company proved not good enough they have gorne a different route and one i would reccomend whitch is a battery equliser this connect to both 12 and 24v batterys and when the 12v is discharged it draws from the 24v's to recharge the 12v battery this fixed the bus companys problems and if you want 12v ignition just get a 24v relay connect it to ignition to switch the 12's

patch697
9th October 2011, 05:38 PM
Paul, I was not having a go at you mate and I did not mean any disrespect.

I will have to try harder with the wording in my posts.

If it was my truck I would not connect a 12 volt accessory to one battery.

But I understand the cost involved with purchasing reducers, so if someone asked me to wire up their truck in this way I would (I would advise them not to) but it is their truck.

If you do decide to wire it up this way, you could try periodically swapping the batteries from drivers side to passengers side every month or so.

You will also need to make sure you connect the accessory to the correct battery, it is the one where the negative post is connected to the body/block.

Rodney

All good Rod, I didn't think you were having a shot mate more just passing on some good advice which im more than happy to support.

If pulling 12v from the 12v side of a 24v system can have a negative effect on a system I was not aware of, better we find out before it happens I say.

Thanks for the heads up mate, your a champ.

Cheers
Paul

Yendor
9th October 2011, 05:47 PM
Hi
New here but have some input Yendor is correct what happnes is when you draw off of the 12v battery it requires more to recharge and because they are charged in a 24v bank the 24v battery gets overcharged and boiled damageing the battery and the 12v gets flattned causeing these issues. as said above you can run a reducer whitch is what a bus company did with the 12 computer on a 24v bus this works quite well for small things radios and phone charges but as the bus company proved not good enough they have gorne a different route and one i would reccomend whitch is a battery equliser this connect to both 12 and 24v batterys and when the 12v is discharged it draws from the 24v's to recharge the 12v battery this fixed the bus companys problems and if you want 12v ignition just get a 24v relay connect it to ignition to switch the 12's

Hi philfree

Thank you for your post.

I haven't heard of this system yet, but from what you are saying is it monitors both batteries and when it detects the 12 volt battery (within the 24 volt system) is low, it will then use 24 volts to charge up the 12 volt battery???

Do you have a link to the company that supplies these units?

Are you affiliated with this company?

If you are I don't think it matters (mods????) just good to be up front, depending on the cost it does sound like a good system.

WoffoDave
10th October 2011, 03:57 PM
The bty equaliser sounds like something we all should have in a 24v system. Where does one go to find out about those and is it worth it for the standard setup (ie just the 2 engine bay bty, not a 3rd accessory bty)??



Dave

philfree
10th October 2011, 08:03 PM
Hi redarc makes a range of them from 3 to 60 amps i would reccomend not going under 20amps http://redarc.com.au/products-and-services/ce-series-charge-equaliser is the link i do not work for them i work for a auto electrision in mackay we do alot of work for Greyhound is this is the bus company i was refering to their problem is on their motorcoaches they are all 24volts except the eton auto shift computer whitch runs 12volts and it needs a realy good supply as it needs good voltage to power the motors on the gearbox to physicaly change gears. in short it generly quite worth it for these setups any good auto electrision should be able to sort you out unless you intend on realy draining the 12v battery like fridge for days with out driving then this is all you should need for those who want a 12v aux battery you can get a unit called bcdc from redarc when wired with ignition it can down size 24volts to 12 and also charge the aux battery the correct way ie boost absorption and float these are more expensive like 6-700 bucks but we have had good sucess with these items. i am happy to help with other questions to do with electrical.

philfree
10th October 2011, 08:17 PM
just worth noteing but how those equlisers work is they make sure their is exactly half the 24voltage in the 12volt side