Wireless LED and battery lighting for trucks - advice please

[Barney]

Morning BR,

A production I will be working on is looking for LV lighting to be included on a number of trucks etc. This will most likely be LED tape or similar, so hopefully not a massive power draw. Not practicable to have power/DMX cables to each (moving) unit.

I'll admit, this is not something I have done before, so am looking for advice and tips from those in the know. I anticipate that I will need some form of wireless DMX transmitter with a receiver on each truck. This and the LED tape can presumably be powered from a battery secreted within the truck.

I am aware of a few wireless DMX solutions, but not sure of the best products to go about this, and also how to connect the (12V / 24V) tape and decoders. I'm sure it's fairly straightforward and within my capabilities, but just wanted to ask those who have done it before for advice on suitable equipment, and any tips on practical installation. For example, does the battery (what type is best?) need a fuse? Does the battery need to be disconnected from the rest of the system for recharging, etc...

I imagine that each set piece will only be used for 15-20 mins on each show, so I am assuming that batteries don't need to be huge - but am happy to take any pointers.

Budget is reasonable, especially if the kit can be re-used on future productions.

Also, is this the sort of thing that can be hired..?

 

Many thanks,
Barney

[alistermorton]

I've used RC4 wireless dimmers for LED tape. They're pretty easy to set up, and you can hire them. Are these plain LED tapes or pixel addressable? The RC4 units I've used have built in dimmers which work really smoothly with LED tape directly, but if you needed to add a pixel decoder they also have a DMX out socket. For power we typically use 12V 7Ah sealed lead acid cells, as they're something we have stock of (one of our crew works in the alarm business and can get them cheaply through his trade channels) but rechargeable AA cells can work well too. You'll need a transmitter and one receiver dimmer per truck.

City theatrical also have excellent solutions, I've just not used them. I recall that DrV is au fait with them

[J Pearce]

You've got everything there really.

Per system
1 wireless DMX transmitter (might need to be SACN if you're doing large amounts of pixels)

Per truck:
1 battery, sized to meet your needs (don't forget longer tech days, 2 show days, notes calls before shows etc.) If you can it's usually helpful to oversize the battery as it improves battery life. 
1 good battery charger (get a smart charger not an old fashioned single current charger).
1 DMX receiver and dimmer/pixel controlller - these can be had as a combined unit.
Power distribution and fusing - useful to add a switch to disconnect the load overnight so you don't drain your battery just running the drivers etc. Becomes more significant with pixel tape which can have a significant quiescent current. 12V batteries can provide a very very large current capable of starting fires, so an inline fuse is a sensible control measure.

It can be helpful to disconnect the load during charging, but it shouldn't be essential. Be aware that voltage can rise as high as 14V during charging, so check what your devices can tolerate. However, if you've added the off switch described above, you can just flick that over.

The drivers can be hired, you might struggle to hire the batteries and cabling bits as these tend to be specific to each production.
 

[sleah]

1 hour ago, J Pearce said:

It can be helpful to disconnect the load during charging, but it shouldn't be essential. Be aware that voltage can rise as high as 14V during charging, so check what your devices can tolerate. However, if you've added the off switch described above, you can just flick that over.

I'd like to reinforce Jon's comment about charging, especially as you've asked what's best. I suggest you play safe and disconnect batteries for charging, either by a mechanical switch or physically disconnecting the battery.

Simplest is probably sealed lead acid - like used in alarms and computer backup supplies. They are readily available, robust and easy to use as they don't need holders and you only need one assuming 12v. You can charge them using a decent 'smart' charger as mentioned, a good car charger would do the job if you're usure what to get. Just look for one's that have multi-stage or trickle charging.

[J Pearce]

I've seen trucks built in such a way that you unplug the battery from the truck and plug it into the charger - which removes any possibility of a helpful SM or stage crew type misunderstanding or forgetting the switches.

[musht]

Pixel, addressable LEDs, lot,lot easier than RGB and drivers, draw out the wiring diagram....

If it's not many per truck, 300 or below,  5V and USB power bank per run, get 2A per outlet on USB. Actual current draw depends on pattern and brightness with most 5V pixels.

Larger power draw, power tool battery, adapter and buck converter. Power density much higher and hassle factor lot lower than lead acid.

Always go for a packaged battery solution, bare 18650 li-on take special care and feeding.

Theatre Wireless RC4 think has specific pixel driver, more DIY , Wled or ESP Pixel stick.

Pixels in few formats, strip, 12mm nodes and now 'seed' strings.

DMX not really applicable to pixels, 170 per universe, sACN is more practical.

Software, pixel mapping in Magicq, Madrix if using a lot, Enttec ELM has great mapping, Xlights is free.

Big list www.awesomeledlist.com

 

[Barney]

Thanks so far.

It's for standard RGB(W) tape rather than pixels at this stage. Fairly short runs of up to 4 metres tape length on each truck.

If I'm understanding this correctly, the RC4 unit can drive the LED tape directly (i.e. without the need for a standard DMX decoder/driver)?

 

[musht]

45 minutes ago, Barney said:

 standard RGB(W) tape rather than pixels at this stage.

Draw out the wiring needed, RGB/W require 4/5 heavy lines between driver and strip and between any joins, any longer than 5m need another 5 core to other end.

SK6812 ,if need RGBW ,  https://www.amazon.co.uk/BTF-LIGHTING-Individually-Addressable-Flexible-Waterproof/dp/B079ZWY8JT/

power pair from battery in parallel round the pieces  , data line from control, daisy chained.

RGBW does have a major power saving on full White , 60LEDs/m probably fit within 2A port of USB or split it into 2  x 2m on 2 ports of larger USB bank , as long as ground is linked.

Use DMX from desk to cue sACN source.? Or is that the catch that puts you off pixels?

 

 

Edited April 26, 2023 by musht

[DrV]

6 hours ago, alistermorton said:

snip....

City theatrical also have excellent solutions, I've just not used them. I recall that DrV is au fait with them

Yes, I can highly recommend City Theatrical's kit. It's not the cheapest but it is VERY solid both mechanically and in terms of RF integrity. They have several combined receivers/ dimmers specifically designed for rgbw and rgbwa tapes and they fade down to zero with absolutely no steps at the bottom end. They also supply good quality tapes as raw materials or encapsulated.

What sort of quantity (total length) of tape are you thinking of per truck?

(Full disclosure - CTI are a client of mine).

Dave 

[alistermorton]

2 hours ago, Barney said:

If I'm understanding this correctly, the RC4 unit can drive the LED tape directly (i.e. without the need for a standard DMX decoder/driver)?

Yes, a DMX4Dim would drive a length of RGBW tape directly. What we have also done is use the el-cheapo LED dimmer boards you can buy on ebay as extra channels, driven off the DMX*DIM's DMX out socket (which is just a 3.5mm jack).

[Barney]

14 hours ago, DrV said:

Yes, I can highly recommend City Theatrical's kit. It's not the cheapest but it is VERY solid both mechanically and in terms of RF integrity. They have several combined receivers/ dimmers specifically designed for rgbw and rgbwa tapes and they fade down to zero with absolutely no steps at the bottom end. They also supply good quality tapes as raw materials or encapsulated.

What sort of quantity (total length) of tape are you thinking of per truck?

(Full disclosure - CTI are a client of mine).

Dave 

Hi DrV,

It will be around 4 - 5 metres of RGB / RGBW tape per truck.

Hopefully I can find a good price from one of the re-sellers.

Thanks,
Barney

[musht]

Be aware  with RGBW , pastels are nice but not always when really wanted pure deep blue, RGB LEDs with integrated white tend to have a bit of glow from the white phosphor portion even when off.

 

 

[Jivemaster]

One previous member had a like thread long ago, his experience was that a sealed lead acid car battery totally died in about a week (not just went flat, wouldn't charge or discharge). Selecting a deep discharge lead acid battery would be better, selecting LiFePO4 would be more expensive but longer life and need a special charger. 

One supplier (www.fogstar.co.uk) is local to you, but I've never used them and have no connection there.

[musht]

Lead acid, wet out question, sealed still heavy, need constant attention even in storage.Left on shelf will self discharge.

NiCd /NiMh AA packs, bulky, need balanced.8-10 cells in series.

Li Po, pouch cells , just don't. No mechanical or electrical protection, incendiary device that outputs power with care.

Li Ion , 18650, vape batteries, on 12V still at 3 or 4 in series, want protected cells. Still need balanced. Kept and used in fire proof bags.

LiFePo4 or Lithium Ferrous Phosphate,LFP, much less inclined to combust than Li Ion, get packaged battery in similar shapes to small lead acid. More expensive but easier to store.

Power tool batteries, probably Li Ion but very protected, get production to hire your new set of batteries from you, converter shoes for Makita, DeWalt etc easy to find on eBay.

Low voltage but very, very high current available from any type of battery, even NiCd. Have smoked a 16mm earth strap shorted across a car battery,by accident, 16mm fuse went before battery went boom.

Need appropriate cable from battery to inline fuse as close to battery as possible.

 

[Jivemaster]

The first problem is to define the necessary load and duration.