itinerant photographer - how to charge batteries ?

10/24/2010 10:09:58 AM · #1

I'm going to travel few monthes in new zealand with a camper-van. I wondering how I'll be able to charge my camera batteries with the van (potentially my computer too).
There is a nikon charger (mh-19) wich is really expensive : more than 300$. Is there a simple and safe solution?

Tamron SP 24-70mm f/2.8 Di VC USD Canon Mount

10/24/2010 10:13:19 AM · #2

We have an inverter in our cars that plugs into the 12V power outlet and provides 300 watts of power (about $40US) and provides enough power to use the laptop and should be able to charge batteries for the camera also.

Mike

Canon EOS-5D Mark II

10/24/2010 10:19:36 AM · #3

Originally posted by keyz:

the camper doesnt have standard outlets to plug into?

alohadave

Pentax K-5

Pentax DA 16-45mm f/4.0 ED AL AF

10/24/2010 10:19:48 AM · #4

Originally posted by kawesttex:

Isn't curious that you go from car battery to inverter to power brick to battery again?

You'd think there would be a way to tap DC directly from the battery to the laptop/camera.

10/24/2010 10:22:18 AM · #5

Originally posted by alohadave:

Originally posted by kawesttex:
We have an inverter in our cars that plugs into the 12V power outlet and provides 300 watts of power (about $40US) and provides enough power to use the laptop and should be able to charge batteries for the camera also.

Isn't curious that you go from car battery to inverter to power brick to battery again?

You'd think there would be a way to tap DC directly from the battery to the laptop/camera.

Some of those solutions are more expensive than the inverter though and you would probably need individual units for the laptop and the battery charger. This gives you one device to power all. We also charge our cell phones on it.

Message edited by author 2010-10-24 10:23:31.

Canon RF 24-70mm f/2.8 L IS

10/24/2010 10:33:38 AM · #6

Originally posted by mike_311:

Originally posted by keyz:
I'm going to travel few monthes in new zealand with a camper-van. I wondering how I'll be able to charge my camera batteries with the van (potentially my computer too).
There is a nikon charger (mh-19) wich is really expensive : more than 300$. Is there a simple and safe solution?

the camper doesnt have standard outlets to plug into?

A campervan is just a van with a bed inside ... it will depend on how the guy who adapt the van did it.

Thanks kawesttex, I'm looking on inverters, it seems to be a good solution. They don't look all reliable but it sounds good for the price.

kirbic

Canon EOS R5

10/24/2010 10:34:25 AM · #7

Some devices, like laptops, require more than 12V; they are more in the 19V range. So you have to convert the DC temporarily to AC and then back to DC again to raise the voltage. This is because a transformer, which can be used to raise voltage with AC, does not work with DC.
For devices like cell phones, which all now use USB to charge (12V by definition) it might be possible to get around the conversion, but you'd need to regulate the voltage The "12V" supply in a vehicle can range up to nearly 15V when the battery is being charged, and normally runs around 14V in operation and 12.8V when the engine is off.

10/24/2010 10:38:29 AM · #8

Originally posted by kirbic:

Good point, I have just found that the inverters easier to power multiple devices. You do have to watch what you plug into them though. I wouldn't try to power my laptop and charge the camera battery at the same time unless you go up to a larger inverter, 500 to 1000W or larger. When you start going to the larger inverters though it seems the price/watt increases.

10/24/2010 10:43:36 AM · #9

I guess I should tell you how to figure out what size inverter you need. Think PIE, Power = Current X Voltage. If you need 1.0 amps at 240 volts you would need at least a 240 watt inverter. If you need 0.5 amp you would only need a 120 watt inverter. I try to allow for about a 20% over rating. If I need 400 watts of power I will look for a 500 watt inverter, this keeps the inverter from working at maximum capacity all the time. If you want to power more than one item at a time just add their wattage together and go from there.

10/24/2010 11:45:54 AM · #10

What do you think about a daily use of an inverter during 3 monthes?

10/24/2010 11:55:00 AM · #11

We've had one plugged in both vehicles for over 3 years. We replaced the first one after about 4 years of use and it was primarily used for a laptop. We travel alot by vehicle, about 50,000 miles a year.

Canon RF 24-70mm f/2.8 L IS

10/24/2010 12:18:02 PM · #12

Ok nice, I'll buy that stuff soon. Thank you Ken.

kirbic

Canon EOS R5

10/24/2010 12:23:38 PM · #13

When buying an inverter, be careful about the specifications. Many of them are rated, ummm, very liberally. They are often rated by "peak wattage" but if you read the fine print, the continuous wattage rating is much less. Know the wattage you will be using, and find an inverter that has at least a 25% greater continuous wattage rating.

Canon RF 24-70mm f/2.8 L IS

10/24/2010 01:42:15 PM · #14

One last thing, I'm using this laptop adapter : //www.power-batteries.net/notebook-charger/dell/df263.html

One the adaptater it's written 110-240~1.5A. For me it's strange to have the same current at 110 and 240V. I think it's quite reasonable that the power of this adapter is 110*1.5=165W ... but a bit extreme if it's 240*1.5=360W. Also, on the website above it's written "Power : 65W"
What do you think about the real power of this device?

Message edited by author 2010-10-24 14:26:22.

kirbic

Canon EOS R5

10/24/2010 03:27:41 PM · #15

Originally posted by keyz:

Yep, the way devices are rated, it is sometimes hard to tell what they will actually draw in normal use. For this adapter, I agree you are justified in taking the 1.5A @ 110V, giving about 165W. Taking another approach, the thing is only putting out 65W (3.34A*19.5V). Even if it is just 50% efficient in conversion, that means power draw will be 130W. Of that 130, 65W is useful power, and the other 65W has to go out as heat. I doubt whether the brick dissipates as much heat as a 65W light bulb, so I'd guess the efficiency is much higher than 50%. 75% to 80% is a much better guess, probably still conservative, in which case the real-world power requirement is about 85W.
Here's what I would do in this situation. I'd use the 130W number, to allow for a safety factor and for "power factor." With AC devices, power is not always the simple product of current times voltage; current can be higher than you expect, and it's typically the current that is important to the inverter. You should be safe with an inverter rated for a continuous power of 150W or more.