Control/Dimming Low Voltage/Parallel/Ah

[CraigG]

Hey gang,
A recent production of ours is utilizing low voltage sources and low voltage lamps to power a platform ring that rotates on stage. There is a revolve inside of the ring that rotates independently, so without spending a ton of money on fiber brushes, etc we've gone the route of using batteries, low voltage lamps and RC4's.

In order to increase the max burn time of the lamps on the ring, we are going to run a bunch of 12v batteries in parallel to increase the Ah's (amp hours). The plan is to take 2 12v 15Ah batteries and run in parallel and one 10Ah, giving us 40Ah of capacity. The question is this - does this also mean that the amps coming from the total load of the battery to the RC4 dimmer equals 40amps? I need to know so I know what lugs and cable to buy for the RC4 dimmers that we are renting.

Thanks for the help!

 

[JD]

Hey gang,
A recent production of ours is utilizing low voltage sources and low voltage lamps to power a platform ring that rotates on stage. There is a revolve inside of the ring that rotates independently, so without spending a ton of money on fiber brushes, etc we've gone the route of using batteries, low voltage lamps and RC4's.

In order to increase the max burn time of the lamps on the ring, we are going to run a bunch of 12v batteries in parallel to increase the Ah's (amp hours). The plan is to take 2 12v 15Ah batteries and run in parallel and one 10Ah, giving us 40Ah of capacity. The question is this - does this also mean that the amps coming from the total load of the battery to the RC4 dimmer equals 40amps? I need to know so I know what lugs and cable to buy for the RC4 dimmers that we are renting.

Thanks for the help!

The amperage will be whatever the load is, not the batteries. If your load is only a couple of amps, you want to put a fuse in line with the battery (Which you should do no matter what) so that any short that may occur will not set fire to the wiring. For example, if you load is drawing 10 amps, put a 12 amp fuse inline. Even though the batteries only are rated at 40 amps, many times that current will be available if a short occurs. You want something in there to act as a fail-safe.

As for capacity, if your batteries are 40 amps and your load is 10 amps, you could stay lit for almost 3 hours. If your load was 20 amps, a bit less than 2 hours. To find out what load you have without adding everything up, borrow an ammeter from a local auto shop and give it a measure. Don't use an AC clamp meter as they will read 0 on a DC circuit.

Also, watch your wire gauges. If your load ends up being high enough and your gauge is too thin, it would be a fire hazard. If you need to use small gauge wire due to the nature of the set piece, then divide it up into smaller loads, each running off of it's own fuse. Pep Boys may become your friend!

 

[jhochb]

Good Morning CraigG

JD is right. Think about it this way, The battery doesn't GIVE amperage. The LOAD TAKES amperage.
Also AUTO batteries are made for high cranking amperage , alot in a short time, not sustained loads. So choose your battery with that in mind.
Batteries plus is also your friend.
12AWG strainded wire should be ok for a 10 amp load.