Nimh Battery Packs for Marshall

Brian, the problem is chemistry. NiMh technology is tricky, as there is no easy way to know when the charge is done. If the pack is undercharged, it is obvious, no juice. If it is overcharged, it is damaged, cooked (might last a few cycles). The only way to charge it right is to monitor internal temperature during charging (Anton Bauer Hytron50), but it makes both the pack and the charger expensive. Looking at the picture, there are 2 wires coming out from the pack (+) and (-), no 3d wire for the temperature sensor. Rated capacity is not everything, the rest of the story is not so exciting...
 
Hey Brian - it's only an extra $100 to send your monitor to Nebtek and get it done right. I've tried a couple of battery pack options and ended up wasting money. I've had 0 problems or hassels since I let Nebtek hook me up.
 
Carlone,

How long do you get off your batteries with the Nebtek? How many do I need to purchases to last a full day powering the monitor?

If it takes a good number of batteries to power you through a full day of shooting, then I might need more chargers to power them back up overnight. In a worst case, which I think I might have on this shoot coming up, I need to shoot all day powering that monitor without any AC around, then go home for the night and recharge everything for the next day. How many batteries and chargers am I going to need to accomplish that?
 
Hi Brian,
The Marshall V-R-70P-HDA only draws 600 Mah of current at 12V. Your Panasonic batteries offer 5400 Mah at 7.2V. The mathematical conversion equates to 5.4 hours per battery, but there will be some power degradation. I would bank on 4.5 - 5 hours worth of runtime per battery just to play it safe. One thing to remember is that the Panasonic Battery plates we use appear to be a bit particular about what batteries they accept. The Panasonic brand batteries always work, but the 3rd party batteries sometimes fit loosely and provide poor contact.

I hope this helps,

Rob
NEBTEK
 
I keep hearing different things about runtime for this conversion. I'm seriously about to pack the monitor up and send it to you guys at Nebtek, but I'm really confused as to how long the batteries will last. I've read Carlone say he can get 4 hours out of the big battery. But then I hear davetronic say he gets 2-2.5 hours out of the same battery. And the math say 4.5-5 (actually the "math" says 5.4). I know it's going to vary, but 2-5 hours is a big window when trying to figure out how many Panny batteries to purchase.
 
Brian my figures are based on field experiences where I'm basically running the monitor non-stop, with a picture up the whole time. I've been tracking about 3 hours pretty consistently. I think I remember Carlone mentioning his longer runs included powering the monitor off (or at least going into standby) in between shots?
 
Hi Brian,
I would most definitely listen to Dave or Carlone...

We have just completed bench testing the unit under ideal conditions inside our shop with a 5400 Mah Panasonic battery... it drained the battery in just under 4 hours. Field usage outdoors (especially in desert conditions) will cause a battery to drain much more rapidly. Also the age of the battery is a consideration, as older batteries do not hold the same amount of a charge as new ones.

I apologize for the delay, but I could only use the figures my technicans gave me on the amps to voltage conversion, until we bench tested. I had been using the Sony NPF-960 (6600Mah) batteries with our Z1U, and they were giving me just about 5 hours at trade shows.

I hope this helps,
Rob DuBree
NEBTEK
 
Thanks guys, that info helps a ton. I just now need to figure out exactly how many batteries to get, and an extra charger probably.
 
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