PAG 95e batteries powering the Alexa

[Martin Parry]

Hi All,

 

I've bought 4 new Pag 95e Batts to power the Alexa (in addition to my PAG 75's) on a TV show. I'm running two batteries together for 24v but when the batteries reach 50% the voltage drops to below 24v and the Alexa cuts out and I'm not getting that long on the 50% that works.

 

The Alexa rig has an onboard monitor for the focus puller and we're using a C - Motion remote focus kit plus a camwave. Is it just a case of too much power for the PAG batteries to handle or could I rewire my cable (I am using an Arri 24v cable from my sled) for 12v to try and get a bit more life out of the PAG's or do I just need more powerful batteries?

 

I have been using an onboard battery but the rig does start to get very heavy towards the end of the day.

 

My rig is a MK-V Evolution.

 

Any advice appreciated.

 

Specs:

The PAG L95e (Model 9310A) is a 14.8V 6.5Ah battery that has a maximum continuous output current rated at 7 amps.

[Brant S. Fagan SOC]

You can run the Alexa on just one battery just fine! Try it! That's how I manage the weight even with a Codex attached, also running on 12vdc (nominal).

[Martin Parry]

I'm trying to run the Alexa from the sled with my pags. It runs fine with it's onboard. Im trying to keep the weight down as I have to wear the rig all day. The director likes the human tripod effect

[Brant S. Fagan SOC]

Tell him that when you have to stand there as a 'meat pod,' he has to have a 35-pound sandbag in his lap for the same time period.

 

Better yet, give him a brief test drive and let him wear your gear, fully freighted with batteries, too. Does wonders for how directors perceive what we do all day.

[Thomas English]

have you tried lowering the Alexa cut out voltage? I run the camera at 12v (through the 24v cable) all the time by simply lowering the cut out really really low.

 

Which model Evolution electronics box do you have?

[Martin Parry]

Yeah I thought of lowering the voltage cut out. I have Howards first run of his steadicam rigs bought it back in 2004 so the electronics are first generation.

 

Do you get more run time out of 12v than 24v cabled battery from the sled?

[Thomas English]

When the camera cuts out have you checked that neither of your L95e's has short time fused? i.e. are both of your lights on? The L95e s only have max out of 7amps so if its just one of them doing your 12v sled whilst also half of the 24v then that single battery can get overloaded very quickly.

 

Apart from trading in your electronics for some V4 electronics I recommend you go 12v. At 12v both batteries are working the 12v system and you have a far better chance. At 12v on the v1 electronics you'll have no problems. I did it loads on my v1 electronics box on the RED. I have had a 4pinxlr to Arri 2pin cable made for all sorts of reasons.

 

Its really an issue with the L95e 's rather than the electronics box. They have a low cut out. I do though absolutely recommend the V4 upgrade. Its very good and solves all the issues people talk about on this forum.

 

Or just put the onboard battery on and eat more protein shakes?

[Martin Parry]

Added an extra battery today to deal with the 12v pull from the sled and the two 95's lasted much longer on the 24v draw from the Alexa. Upgrading to a V4 is probably the way to go but I'll get a 12v cable made up to run the Alexa in the short term.

 

Thanks for the advice Thomas much appreciated.