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Low AC battery & DSLR?

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#1 Footbag

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Posted 11 March 2013 - 10:29 AM

The last two nights I went out, my DSLR has been acting funny. The first night, my camera kept shutting down intermittently. Right before giving up, my mount wouldn't slew. It was tracking but ignored my GOTO commands. At that point, I figure it was my powerpack dying and I went in and charged it.

With what I though was a charged powerpack, I did some solar observing during the day, then set it up for imaging. I polar aligned and got a single good frame, and then my camera started giving me garbled pictures. Then it began shutting down intermittently.

I'm thinking it was a dead/dying battery, but it was suggested that it could also be a bad cable. I did run all of my wires through my mount in the meantime.

Has anyone who had a battery die have the DSLR start giving garbled pictures then shutdown intermittently? This is using an AC adapter & Duracell powerpack. I did test the cable and couldn't reproduce the problem.

#2 guyroch

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Posted 11 March 2013 - 12:18 PM

What test did you run on the cable to conclude it was not the cable? My experience tells me it's the cable.

Guylain

#3 Footbag

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Posted 11 March 2013 - 12:28 PM

I attached the suspected cable, and set the camera on a 999s exposure and twisted and turned the cable in every way possible. I did all I could to reproduce the error, but nothing. I did this with both the battery and the power supply.

I did order two replacement cables, but I'm just wondering if my power supply isn't going bad. My mount did stop slewing on a goto command the first night. That's usually power I think.



#4 fmhill

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Posted 11 March 2013 - 12:56 PM

Check the date of manufacture of your Duracell power pack...

I purchased one in the past 6 months, had trouble with it holding a charge and turned out in was manufactured 3 years previous to my purchasing it. Looked at a second brand new one and it was the same date of manufacture... 3 years without being charged will greatly reduce the capacity of the battery...

Add to this the use of it to power an AC adapter and you are putting a heavier load on it than using all DC powered only devices. The process of changing a low(12 Volt) battery voltage to 110 VAC and then back to a low 7-8 VDC for the camera is only about 45%-50% efficient and probably consumes more of your battery capacity than any other single device you might use while imaging with the exception of a Laptop...

Get a 12VDC adapter for your camera, one source is Astronomiser: http://www.astronomi.../canonpower.htm

#5 Footbag

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Posted 11 March 2013 - 01:46 PM

I purchased it in November of 09 and it was manufactured in July of that year. I have kept it plugged in charging when not in use, but maybe I'm hitting the end of it lifetime?

I knew the AC adapter was inefficient, but I figured with 27Ah, I had more then enough power. Now I'm not so sure, and I plan on adding dew heaters, focusers, and other power consumers.

Just by the numbers, I cannot find a better power supply then the Duracell, but I have seen complaints of them dying early. And it appears the battery isn't replaceable.

#6 zawijava

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Posted 11 March 2013 - 02:10 PM

May I suggest that you figure out ALL your power demands [in Amp Hours] both presently and near future, then double that since you can [and should] only discharge a good deep cycle AGM about 50%. Then purchase a really good/fresh AGM battery [for instance Deka] that will meet your needs. It's fairly easy to put together a fused DC power station of your own making.

-Tim

I purchased it in November of 09 and it was manufactured in July of that year. I have kept it plugged in charging when not in use, but maybe I'm hitting the end of it lifetime?

I knew the AC adapter was inefficient, but I figured with 27Ah, I had more then enough power. Now I'm not so sure, and I plan on adding dew heaters, focusers, and other power consumers.

Just by the numbers, I cannot find a better power supply then the Duracell, but I have seen complaints of them dying early. And it appears the battery isn't replaceable.



#7 fmhill

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Posted 11 March 2013 - 03:10 PM

I think Tim has the right idea... That is probably what I will do when the time comes that I need to replace the two Duracell Jumpstart units that I have.

One of my complaints with Duracell is that there was no technical documentation supplied. I have no idea if the internal charger circuit has a float charge feature. If it does, then leaving it plugged in charging is OK, if the built in charger circuit is a continuous output voltage with no foldback, then, yes, you will greatly affect the life of the battery leaving it charged in all the time...

With a proper foldback charger circuit, if you do leave it plugged in charging all the time when you are not using it, tha battery may last many years. I have a diesel tractor battery still in use that was purchased in 2001 however I use a BatteryMINDer(brand) fold back charger on it that gets plugged in when the tractor is not in use. One needs this type of charger when living in New England and the tractor is only used for firewood cutting/hauling on a seasonal basis or snow removal in the winter... In 11 years it has never failed to start however this year the tractor will be getting a new battery as the original is getting pretty tired... I also charge the Duracell Jumpstart units with a BatteryMINDer charger but I only charge them once a month when not being used, and only leave them on charge for two or three days at a time.

I do think a AGM deepcycle battery is a wiser choice. If you shop around you will find them with built in carry straps, I have two Deka AGM deep cycle batteries in my RV trailer that are about 5 years old and still in excellent operating condition... A Deka AGM deep cycle 33 AH will be my next portable mount power source...

#8 Footbag

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Posted 11 March 2013 - 10:37 PM

I have read that it does have the float feature and can be plugged in all the time. Its actually written on the back of the battery.

Now, I'm wondering whether I can replace the battery. I found one online, but the manufacture specs say the battery isn't replaceable.

If it's not, I'll look into building something with a nice battery, a powered USB hub, AC and DC. A cheap toolbox would probably do.

#9 Jerry Lodriguss

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Posted 12 March 2013 - 02:35 AM

Hi Adam,

More than three years on the battery?

It's the battery going bad.

Just go to Walmart and buy a 75 amp hour deep-cycle marine battery. NOT a starter battery!

Jerry

#10 Phil Sherman

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Posted 12 March 2013 - 02:45 PM

I recently took Jerry's suggestion and purchased a large deep cycle marine battery. I purchased a large plastic battery box from WM and added a self resetting automotive circuit breaker to the included plastic divider that makes the box usable for different sized batteries. A set of Anderson PowerPole connectors lets me quickly connect my field power supply box which uses DC converters to supply 13.6V, 8V and 5V for running various devices.

My 17AH AGM battery will run the astro gear for an evening so I figure that I'll get at least three nights from the deep cycle battery. The bigger marine battery will also let me power my laptop using the 12V DC supply I purchased for it some time ago.

Phil






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