OTish - 12-24V Transformer

| Seeing as I always get a good answer here, and the question is mod-related.. | does anyone know where I can get a | transformer to convert 12V>24V for use in a van? We want to light the inside | of the van up and we've loads and loads | of old bus strip lights and electrical bits but they're all 24V. They're | excellent for what we need, but how to wire then up? | | We could use standard 2 12V batteries in Serial for the 24V, but then that | screws the rest of the electrics, unless we start getting complex and wire | then in both serial and parallel, with separate take offs for each. | | I was just thinking there must be something I can plug in that does the | same...

Simple buy a 24V mains battery charger.

are lots of other types and places who sell them. Build it in to the van if you want.

Charge the 24V batteries up overnight and run them down during the day. Or if you have an electricity supply leave them charging while the batteries are in use. That is how the caravanners do it but for 12V

Wire them both in serial and in parallel????? You should try drawing yourself a little circuit diagram then come back and tell us if you've spotted the flaw in that little theory.

Nah .. let him try it. Maybe on something like forklift batteries!!!

A large enough 12 to 24 volt invertor is likely to cost more than simply buying new 12 volt fluorescents.

You can't. Transformers only work on AC and the van is DC.

mod-related..

Seems to me you have answered your own question except how do you charge the twin battery setup, it does get complicated but the only other answer would be to use an inverter to give 240v ac then use that to run a 24v battery charger to power the lights (possibly with 2 small 12v batteries in series to act as a damper after the 24v charger) also you could try the lights on

12v they might work! or if not can the lights be modified to work on 12v. Please let the group know how you get round this one!

If after doing the diagram you still want to give it a go, feel free to make a video to educate those you leave behind.

[...]

An additional 24v alternator?

A

Sounds like you want something like this:

they are in new south wales and I don't know if they have a UK distributor.

Ah a UK based company making DC/DC converters:

Sold by: a 72w 12v to 24v unit is £82+vat

Maplin sell 12v 16 watt florries for 14.99 inc, so 5 giving 80 watts would cost less...;-) And I'm sure if you trawl the various electronics suppliers like CPC etc you'll find them cheaper than Maplin.

I was wondering how long it'd take someone to suggest changing the bulbs...

It's usually possibly to add a second battery and drive a second alternator. This way you still have +12v starter motor and can leave the rest of the electrics alone, but add a 24v battery, alternator and circuits for the extra kit.

You can also get +24v by using a gadget to do it, e.g. you can user an inverter to get 240v AC and just hang a halfords battery charger with a 12/24v switch off that, generating a few amps of +24v at what will probably be a poor efficiency but also a reasonably cheap and simple solution. Might even be useful to have 240v AC available but don't imagine you can boil a kettle off the sensibly cheap stuff.

Not the bulbs (tubes) - they are the same. It's the ballasts which are different.

A 300 watt mains invertor costs around 35 quid. Most kettles are 2.5 kW. With a 100% efficient invertor you'd be drawing over 200 amps from your battery. Not recommended. ;-) Not that there's any point as a 12 volt element kettle would be more efficient anyway.

Most invertors fail when overloaded as it's difficult to protect them properly - a fuse wouldn't blow fast enough. And most people seem incapable of reading the wattage needed by the appliance they wish to use.

I've got a few (300 watt) such overloaded ones now fixed and as new for 25 quid plus postage.

It was somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember "radar" saying something like:

You could connect them in series for a 24v takeoff and arrange a charge relay which will disconnect the series and connect them in parallel for charging. It's old stuff, but a pain in the arse.