DigiPower Accessories

I bought a DImage 5 and some DigiPower accessories last week. I bought the DPS 8000 battery pack with the Minolta cable and the DigiPower AC adapter for Minolta cameras. However, I've had a couple problems. On both items, if the power connector going into the camera is pulled or bumped slightly - the camera powers off. This has happened multiple times while saving images. Also, the battery pack is only lasting me about 30 minutes - about 20-30 shots (with just the LCD - but using the flash).

In reviewing the web just now, I see that the Minolta versions of these DigiPower accessories actually say DIMAGE V - not DIMAGE 5. I interpreted DIMAGE V to mean DIMAGE 5. However, it seems that there's a much older camera from Minolta called the DIMAGE V. So, my question is - are the accessories supposed to with the DIMAGE 5 or not? (I did find some websites that said they would.) Has anyone else experienced these issues?

Thanks,
-Chris

Oops! It does matter. You need the lithium pack as the NiMH pack does not provide enough power. The DiMage V is another device.

As for power packs, I have a PowerEx, and it has the same problem with the chord slipping out. You can put batteries in the camera, btw, at the same time. After stuggling with having a cord on my camera, a Di7, I paid the extra cash and bought 1800mAh batteries (GP1800s from http://www.greenbatteries.com is what I use). They last significantly longer than the 1600s, and are easier to handle than a power pack. (I do use the power pack when I am doing tripod work, though.)

Chris Edgington said:

I bought a DImage 5 and some DigiPower accessories last week. I
bought the DPS 8000 battery pack with the Minolta cable and the
DigiPower AC adapter for Minolta cameras. However, I've had a
couple problems. On both items, if the power connector going into
the camera is pulled or bumped slightly - the camera powers off.
This has happened multiple times while saving images. Also, the
battery pack is only lasting me about 30 minutes - about 20-30
shots (with just the LCD - but using the flash).

In reviewing the web just now, I see that the Minolta versions of
these DigiPower accessories actually say DIMAGE V - not DIMAGE 5. I
interpreted DIMAGE V to mean DIMAGE 5. However, it seems that
there's a much older camera from Minolta called the DIMAGE V. So,
my question is - are the accessories supposed to with the DIMAGE 5
or not? (I did find some websites that said they would.) Has anyone
else experienced these issues?

Thanks,
-Chris

Click to expand...

--Regards,RS BlumRedesigned! DiMage 7 links, pictures, open letter to Minolta, and tips at http://www.luiswatkins.com/homepages/dimage7/

Chris,

I have the Minolta EBP-100 power pack and I am very happy with it. It consists of two lithium-ion NP-100 batteries, each 1600MA plus an AC charger. The power cable connector to the camera fits well and gives me no problems although I have bumped or tugged it often.

George

Chris Edgington said:

I bought a DImage 5 and some DigiPower accessories last week. I
bought the DPS 8000 battery pack with the Minolta cable and the
DigiPower AC adapter for Minolta cameras. However, I've had a
couple problems. On both items, if the power connector going into
the camera is pulled or bumped slightly - the camera powers off.
This has happened multiple times while saving images. Also, the
battery pack is only lasting me about 30 minutes - about 20-30
shots (with just the LCD - but using the flash).

In reviewing the web just now, I see that the Minolta versions of
these DigiPower accessories actually say DIMAGE V - not DIMAGE 5. I
interpreted DIMAGE V to mean DIMAGE 5. However, it seems that
there's a much older camera from Minolta called the DIMAGE V. So,
my question is - are the accessories supposed to with the DIMAGE 5
or not? (I did find some websites that said they would.) Has anyone
else experienced these issues?

Thanks,
-Chris

Click to expand...

RS Blum said:

Oops! It does matter. You need the lithium pack as the NiMH pack
does not provide enough power. The DiMage V is another device.

Click to expand...

What I don't understand is that the DPS8000 claims to be 2700mAh (there are 5 cells in the pack). Do you add the mAh of each battery to get the total? (So, if you are using 4 1600mAh batteries - you'd have 6400mAh?) If everybody is saying 1600mAh NiMH batteries work fine - why in this case is the lithium pack needed?

Thanks,
-Chris

Ah, somebody who went the "standard" route, finally. How would you rate the battery life of the pack? Have you measured it. About how much did it cost?

G Yee said:

George

Chris Edgington said:

I bought a DImage 5 and some DigiPower accessories last week. I
bought the DPS 8000 battery pack with the Minolta cable and the
DigiPower AC adapter for Minolta cameras. However, I've had a
couple problems. On both items, if the power connector going into
the camera is pulled or bumped slightly - the camera powers off.
This has happened multiple times while saving images. Also, the
battery pack is only lasting me about 30 minutes - about 20-30
shots (with just the LCD - but using the flash).

In reviewing the web just now, I see that the Minolta versions of
these DigiPower accessories actually say DIMAGE V - not DIMAGE 5. I
interpreted DIMAGE V to mean DIMAGE 5. However, it seems that
there's a much older camera from Minolta called the DIMAGE V. So,
my question is - are the accessories supposed to with the DIMAGE 5
or not? (I did find some websites that said they would.) Has anyone
else experienced these issues?

Thanks,
-Chris

Click to expand...

Click to expand...

--Regards,RS BlumRedesigned! DiMage 7 links, pictures, open letter to Minolta, and tips at http://www.luiswatkins.com/homepages/dimage7/

Chris Edgington said:

Chris Edgington said:

Oops! It does matter. You need the lithium pack as the NiMH pack
does not provide enough power. The DiMage V is another device.

Click to expand...

What I don't understand is that the DPS8000 claims to be 2700mAh
(there are 5 cells in the pack). Do you add the mAh of each battery
to get the total? (So, if you are using 4 1600mAh batteries - you'd
have 6400mAh?) If everybody is saying 1600mAh NiMH batteries work
fine - why in this case is the lithium pack needed?

Click to expand...

Why lithium? It's all in the voltages. NiMH provides 1.2v x 4, or 4.8 volts. Lithium-ion packs provide about 7.2 volts. "mAh" means millamps per hour, and is a capacity value rated at the supplied output voltage. Each 1600mAh battery provides 1600mAh at 1.2volts; combined in a set of 4, they provide 1600mAh at 4.8v. All batteries have a voltage curve, falling off from the maxium linearly until a sudden drop-off before complete discharge. If (hypothetically - I don't know the figure), the D7/D5 requires a minimum 4.7 volts, the drop-off would be sooner for NiMH than for Li-ion. The higher the mAh rating of the battery, all factors being the same, the greater the capacity of the cell and (I understand) the gentler the voltage drop slope will be. Btw, it appears the Minolta will take 4xNP-100 Fujifilm batteries (3.6v@1350mAh) in the battery compartment (my theory, anyway, based on the Minolta accessory list). NP-100s are Li-ion, expensive, and probably what Minolta designed the camera optimally to use. NP-100s would probably more than last twice as long as NiMH (this is a guess based on the above information). GP1800s are a good compromise of price vs. longevity.

Links:
Minolta D7/D7 accessory list: http://www.dimage.minolta.com/d7d5/page08.html

NP-100 prices: http://shopper.cnet.com/shopping/resellers/0-11809-311-399954-0.html

NP-100 picture: http://www.ritzcamera.com/cgi-bin/ncommerce3/ExecMacro/ritzcamera/home.d2w/report?redirect=http://www.ritzcamera.com/cgi-bin/ncommerce3/ProductDisplay&prrfnbr=29677&prmenbr=153&STORENAMEPASS=ritzcamera&shfield2=CNETCO--Regards,RS BlumRedesigned! DiMage 7 links, pictures, open letter to Minolta, and tips at http://www.luiswatkins.com/homepages/dimage7/

Chris Edgington said:

Chris Edgington said:

Oops! It does matter. You need the lithium pack as the NiMH pack
does not provide enough power. The DiMage V is another device.

Click to expand...

What I don't understand is that the DPS8000 claims to be 2700mAh
(there are 5 cells in the pack). Do you add the mAh of each battery
to get the total? (So, if you are using 4 1600mAh batteries - you'd
have 6400mAh?) If everybody is saying 1600mAh NiMH batteries work
fine - why in this case is the lithium pack needed?

Thanks,
-Chris

Click to expand...

Hi Chris,

The series string is still 2700 ma-H - just like one of the individual cells. The parameter that multiplies by the number of cells is the energy capacity expressed in watt-hours. That’s 2.7 ma-H X 1.2 volts per cell =3.24 watt-hours per cell or 16.2 watt-hours for the five. Now that is a simplification. The actual energy rating is a function of the current drain profile and works out to be the area under the curve product of the current delivered times the terminal voltage at any instant in time - over the time it takes to discharge the battery down to some end of life terminal voltage (where the voltage is dying fast).

The DPS8000 should have worked just fine - with much much more capacity then what fits in the D7. Its five cells or six volts which is more then you get from the cameras internal four cells and 2700 ma-H is much more then the 1800 ma-H capacity you can stick inside the camera. Its likely there is a bad cell or a defective charger.

The only reason for a Lithium Ion pack would be it's 7.2 volt rating (for two cells in series). Normally the extra voltage would only be wasted as heat but the D7's switching supply converts the cells output efficiently to what the camera needs.

The reason the D7 does so poorly with its four cells is that its low voltage shut down point leaves about 20% to 40% of the capacity of the four 1800 ma-H cells unused because of the low voltage cut off point. This is why the extra NiMH cell in series or the two Lithium Ion cells do so much better then you would expect based on just their ma-H capacity alone. The extra voltage makes it possible to recover much more of the batteries capacity.

Pete

RS Blum wrote:
Btw, it

RS Blum said:

appears the Minolta will take 4xNP-100 Fujifilm batteries
(3.6v@1350mAh) in the battery compartment (my theory, anyway, based
on the Minolta accessory list).

Click to expand...

You better check the manual or contact Minolta before you try this. If you put four of these in series inside the Camera, you'll be powering it from 14.4 volts. This could mean instant death or a shortened life for the camera switching power supply - OR it is possible the supply will just take it in stride - it all depends on the details of it's design.

My guess is that someone at Minolta thought the higher then 1800 ma-H capacity of alkalines was more then enough for the camera and either forgot how badly it falls off at the high currents found in the D7 OR never planned on the camera drain being as high as it is until they saw it when they put all the pieces

together on the lab bench - - - and then it was too late (time to market pressures).

I think the low voltage trip point was designed around alkaline cells 1.5 volts per cell initial voltage (they did ship early units with alkaline) and when they saw they were in trouble they made a quick shift to NiMH without re-designing the switch mode power supply and / or low voltage shut off point for the lower end of capacity voltage of NiMH. Just my theory but I think the partial proof is that 5 1800 ma-H NiMH cells in series deliver far more operating time then the 25% increase in energy capacity from the extra cell would suggest.

Pete

Hi, I also have that DigiPower ac adapter from BestBuy local store for my D5. It claims that can be used with Dimage 5. I thought the voltage and current is in the working range.

The only problem is that the connection is not tight enough. So as you said, it will power off sometime.
Just try to avoid pull the cable when you are recording data.

Best wish

Bunnet

Chris Edgington said:

I bought a DImage 5 and some DigiPower accessories last week. I
bought the DPS 8000 battery pack with the Minolta cable and the
DigiPower AC adapter for Minolta cameras. However, I've had a
couple problems. On both items, if the power connector going into
the camera is pulled or bumped slightly - the camera powers off.
This has happened multiple times while saving images. Also, the
battery pack is only lasting me about 30 minutes - about 20-30
shots (with just the LCD - but using the flash).

In reviewing the web just now, I see that the Minolta versions of
these DigiPower accessories actually say DIMAGE V - not DIMAGE 5. I
interpreted DIMAGE V to mean DIMAGE 5. However, it seems that
there's a much older camera from Minolta called the DIMAGE V. So,
my question is - are the accessories supposed to with the DIMAGE 5
or not? (I did find some websites that said they would.) Has anyone
else experienced these issues?

Thanks,
-Chris

Click to expand...

Or they figured out too late tha the Li batteries would push them out of the market price range.

Pete said:

Pete said:

appears the Minolta will take 4xNP-100 Fujifilm batteries
(3.6v@1350mAh) in the battery compartment (my theory, anyway, based
on the Minolta accessory list).

Click to expand...

You better check the manual or contact Minolta before you try this.
If you put four of these in series inside the Camera, you'll be
powering it from 14.4 volts. This could mean instant death or a
shortened life for the camera switching power supply - OR it is
possible the supply will just take it in stride - it all depends on
the details of it's design.

My guess is that someone at Minolta thought the higher then 1800
ma-H capacity of alkalines was more then enough for the camera and
either forgot how badly it falls off at the high currents found in
the D7 OR never planned on the camera drain being as high as it is
until they saw it when they put all the pieces
together on the lab bench - - - and then it was too late (time to
market pressures).

I think the low voltage trip point was designed around alkaline
cells 1.5 volts per cell initial voltage (they did ship early units
with alkaline) and when they saw they were in trouble they made a
quick shift to NiMH without re-designing the switch mode power
supply and / or low voltage shut off point for the lower end of
capacity voltage of NiMH. Just my theory but I think the partial
proof is that 5 1800 ma-H NiMH cells in series deliver far more
operating time then the 25% increase in energy capacity from the
extra cell would suggest.

Pete

Click to expand...

Jim Underwood said:

Or they figured out too late tha the Li batteries would push them
out of the market price range.

Click to expand...

Someone suggested that was why they were slow to include NiMH cells with the camera.

When the camera was first introduced at $1499 list, the extra $50 or so it would have taken to include 4 NiMH cells and a charger doesn't seem like much of an adder. Even the Lithium Ion external packs (but not Minolta's) are about the same price. Now that the street price of the camera is less then half the original list price, the better battery solutions are an even greater percentage of the package - but not too many people who like the camera give it a second thought.

It's the amount of POWER delivered that is much higher. The lithium cells @ 3.6 V deliver 3x the power of NiMH (at 1.2V) with the same current rating. The NP-100s are rated at 1350 mAH @ 3.6V = 4.86 watt-hours. the best NiMH delivers

1800 mAH @ 1.2 V = 2.16 watt -hours hence the NP100 will (theoretically) last 4.86/2.16 = 2.25x as long as the NiMH cell and not EVEN worth the difference between $4.00 vs. $50.00 difference in price (IMHO).

The DPS8000 will deliver 7.2V x 2.7A = 19.4 watt hours, only a little better than 2 times the capacity of a set of 4 NiMH cells. Hence your results are expected (Sorry)

Jim

RS Blum said:

Chris Edgington said:

RS Blum said:

Oops! It does matter. You need the lithium pack as the NiMH pack
does not provide enough power. The DiMage V is another device.

Click to expand...

What I don't understand is that the DPS8000 claims to be 2700mAh
(there are 5 cells in the pack). Do you add the mAh of each battery
to get the total? (So, if you are using 4 1600mAh batteries - you'd
have 6400mAh?) If everybody is saying 1600mAh NiMH batteries work
fine - why in this case is the lithium pack needed?

Click to expand...

Why lithium? It's all in the voltages. NiMH provides 1.2v x 4, or
4.8 volts. Lithium-ion packs provide about 7.2 volts. "mAh" means
millamps per hour, and is a capacity value rated at the supplied
output voltage. Each 1600mAh battery provides 1600mAh at 1.2volts;
combined in a set of 4, they provide 1600mAh at 4.8v. All
batteries have a voltage curve, falling off from the maxium
linearly until a sudden drop-off before complete discharge. If
(hypothetically - I don't know the figure), the D7/D5 requires a
minimum 4.7 volts, the drop-off would be sooner for NiMH than for
Li-ion. The higher the mAh rating of the battery, all factors
being the same, the greater the capacity of the cell and (I
understand) the gentler the voltage drop slope will be. Btw, it
appears the Minolta will take 4xNP-100 Fujifilm batteries
(3.6v@1350mAh) in the battery compartment (my theory, anyway, based
on the Minolta accessory list). NP-100s are Li-ion, expensive, and
probably what Minolta designed the camera optimally to use.
NP-100s would probably more than last twice as long as NiMH (this
is a guess based on the above information). GP1800s are a good
compromise of price vs. longevity.

Links:
Minolta D7/D7 accessory list:
http://www.dimage.minolta.com/d7d5/page08.html
NP-100 prices:
http://shopper.cnet.com/shopping/resellers/0-11809-311-399954-0.html
NP-100 picture:

http://www.ritzcamera.com/cgi-bin/ncommerce3/ExecMacro/ritzcamera/home.d2w/report?redirect=http://www.ritzcamera.com/cgi-bin/ncommerce3/ProductDisplay&prrfnbr=29677&prmenbr=153&STORENAMEPASS=ritzcamera&shfield2=CNETCO
--
Regards,
RS Blum

Redesigned! DiMage 7 links, pictures, open letter to Minolta, and
tips at http://www.luiswatkins.com/homepages/dimage7/

Click to expand...

Jim Underwood said:

The DPS8000 will deliver 7.2V x 2.7A = 19.4 watt hours, only a
little better than 2 times the capacity of a set of 4 NiMH cells.
Hence your results are expected (Sorry)

Click to expand...

Not quite - the DPS-8000 is a 6 volt (5 cells in series) 2700 ma-H capacity per cell NiMH pack and it should have a very long run time with the D7 (but there is a problem with power connector size). The ma-H or Watt-Hour rating of the cell rating of the cell (or pack) is not the whole story.

The main problem with four 1800 ma-H cells in series in the D7 is that the cameras low voltage trip point calls the cells empty before they actually are. By some estimates, there is 20% to 40% capacity left. Properly functioning five cell 1800 ma-H NiMH packs with working chargers are delivering over double the operating time compared with the four 1800 ma-H NiMH cells you can put inside the D7. And that is well over the 25% increase you would expect from the extra cell. So the same five cell string with 2700 ma-H cells will do better yet. The key is that the extra voltage provided by the fifth cell lets you tap much more of the capacity of a five cell string.

Pete

Pete,

Yesterday I picked up the Dps-8000 from Ritz and charged it for 8-hrs as the instructions specify. I also bought the Rayovac 1-hour charger from Best Buy and charged 4 Monster 1800mah NIMH batteries for 1-hour. This evening I got about 30 shots from the Dps-8000 and over 100 from the Monster's before I got tired pushing the release button. Power level was still on full. This was shooting one after the other. No flash. I am going to try the Digipower charged for 12+ hours tomorrow. The Digipower charges itself by connecting to its own power supply.

Incidently, I never got more than 30 shots from 4+ hours charging with the Monster charger or 16+ from the Quest. I don't what the breakin there might me for the Dps-8000, if any.
Marty

Pete said:

Chris Edgington said:

Pete said:

Oops! It does matter. You need the lithium pack as the NiMH pack
does not provide enough power. The DiMage V is another device.

Click to expand...

What I don't understand is that the DPS8000 claims to be 2700mAh
(there are 5 cells in the pack). Do you add the mAh of each battery
to get the total? (So, if you are using 4 1600mAh batteries - you'd
have 6400mAh?) If everybody is saying 1600mAh NiMH batteries work
fine - why in this case is the lithium pack needed?

Thanks,
-Chris

Click to expand...

Hi Chris,

The series string is still 2700 ma-H - just like one of the
individual cells. The parameter that multiplies by the number of
cells is the energy capacity expressed in watt-hours. That’s 2.7
ma-H X 1.2 volts per cell =3.24 watt-hours per cell or 16.2
watt-hours for the five. Now that is a simplification. The actual
energy rating is a function of the current drain profile and works
out to be the area under the curve product of the current delivered
times the terminal voltage at any instant in time - over the time
it takes to discharge the battery down to some end of life terminal
voltage (where the voltage is dying fast).

The DPS8000 should have worked just fine - with much much more
capacity then what fits in the D7. Its five cells or six volts
which is more then you get from the cameras internal four cells and
2700 ma-H is much more then the 1800 ma-H capacity you can stick
inside the camera. Its likely there is a bad cell or a defective
charger.

The only reason for a Lithium Ion pack would be it's 7.2 volt
rating (for two cells in series). Normally the extra voltage would
only be wasted as heat but the D7's switching supply converts the
cells output efficiently to what the camera needs.

The reason the D7 does so poorly with its four cells is that its
low voltage shut down point leaves about 20% to 40% of the capacity
of the four 1800 ma-H cells unused because of the low voltage cut
off point. This is why the extra NiMH cell in series or the two
Lithium Ion cells do so much better then you would expect based on
just their ma-H capacity alone. The extra voltage makes it possible
to recover much more of the batteries capacity.

Pete

Click to expand...

Point taken. Here's something else to consider: the bull---- factor:

http://www.steves-digicams.com/maha_powerbank.html

Pete said:

Pete said:

The DPS8000 will deliver 7.2V x 2.7A = 19.4 watt hours, only a
little better than 2 times the capacity of a set of 4 NiMH cells.
Hence your results are expected (Sorry)

Click to expand...

Not quite - the DPS-8000 is a 6 volt (5 cells in series) 2700 ma-H
capacity per cell NiMH pack and it should have a very long run time
with the D7 (but there is a problem with power connector size). The
ma-H or Watt-Hour rating of the cell rating of the cell (or pack)
is not the whole story.

The main problem with four 1800 ma-H cells in series in the D7 is
that the cameras low voltage trip point calls the cells empty
before they actually are. By some estimates, there is 20% to 40%
capacity left. Properly functioning five cell 1800 ma-H NiMH packs
with working chargers are delivering over double the operating time
compared with the four 1800 ma-H NiMH cells you can put inside the
D7. And that is well over the 25% increase you would expect from
the extra cell. So the same five cell string with 2700 ma-H cells
will do better yet. The key is that the extra voltage provided by
the fifth cell lets you tap much more of the capacity of a five
cell string.

Pete

Click to expand...

MartyB said:

Pete,
Yesterday I picked up the Dps-8000 from Ritz and charged it for
8-hrs as the instructions specify. I also bought the Rayovac
1-hour charger from Best Buy and charged 4 Monster 1800mah NIMH
batteries for 1-hour. This evening I got about 30 shots from the
Dps-8000 and over 100 from the Monster's before I got tired pushing
the release button. Power level was still on full. This was
shooting one after the other. No flash. I am going to try the
Digipower charged for 12+ hours tomorrow. The Digipower charges
itself by connecting to its own power supply.
Incidently, I never got more than 30 shots from 4+ hours charging
with the Monster charger or 16+ from the Quest. I don't what the
breakin there might me for the Dps-8000, if any.
Marty

Click to expand...

Hi Marty,

Your not the first person to post these results. It makes me think that maybe the DPS-8000 is not what it's claimed to be - five NiMH 2700 ma-H cells in series. The only thing I found on them so far was some add copy that was pasted on e-bay - and the following from some store copy:

Features & Specifications ( http://www.d-store.com/d-store/DigiPower/index.htm ):

Designed to work with most popular Digital Cameras when used with the correct camera connector cable. (connector sold seperatley)

Powerful 6 volt nickel metal hydride battery pack - Designed with five 5/4 "AA" Size - 2700 mAH Batteries..
Memory Free - Capable of providing power for over 1200 pictures in most cameras.

Lightweight - 5.5 oz. - Ergonomically designed. - Size : 2"w x 3"h x 3/4"d (with Carrying Case)
Built -In over-Charge Protection

Comes with 8-12 Hour AC Charger-, Genuine Leather Case, and a 360 degree Secured Swivel Belt Clip.
Complete pack is also small enough to fit in your shirt pocket

DPS 8000 $39.95
Cable Connector $9.95

---

First problem I see is that even 7/5 AA Gold Peak High Capacity Series* NiMH cells are not 2700 ma-H - they are more like 1900 ma-H. The second is that they recommend an 8-12 hour charge. But these should still do a lot better then the four 1800 ma-H cells you can put into the camera - when used under the same conditions. My guess is that there are two possibilities: The cells may need conditioning, and the charger may be a little on the cheap in terms of capacity. Here's the scoop on voltage. With the charger connected and the cells fully charged, you should be seeing about 1.5 volts per cell or 7.5 volts at the pack terminals. When you disconnect the charger, the pack terminal voltage should decline to the vicinity of 1.4 volts per cell or about 7 volts after ten minutes to a half hour. At the beginning of use with the D7 after about 20 minutes, with the LCD off - EVF on, the per cell voltage will be about 1.3 volts or 6.5 volts across the pack. The voltage will steadily decline with use and the cells will be near the end of charge at about 1.1 volts per cell or 5.5 volts for the pack. At 1 volt per cell, things are crashing fast. All below the 1.4 volts per cell are with the pack loaded by the camera - not sure if there is a way to read this with the pack plugged in to the camera.

Bottom line is that, by the numbers and considering the higher voltage from the fifth cell and assuming working cells and charger and conditioned cells, you should be seeing significantly better results then with four internal 1800 ma-H NiMH cells - under the same kind of operating conditions.

Pete

• http://www.gpbatteries.com.hk/industrial/NiMH/CY9VPR/Cylindrical/CYTeData.asp

Check tis review out:

http://www.steves-digicams.com/maha_powerbank.html

MartyB said:

Pete said:

Chris Edgington said:

MartyB said:

Oops! It does matter. You need the lithium pack as the NiMH pack
does not provide enough power. The DiMage V is another device.

Click to expand...

What I don't understand is that the DPS8000 claims to be 2700mAh
(there are 5 cells in the pack). Do you add the mAh of each battery
to get the total? (So, if you are using 4 1600mAh batteries - you'd
have 6400mAh?) If everybody is saying 1600mAh NiMH batteries work
fine - why in this case is the lithium pack needed?

Thanks,
-Chris

Click to expand...

Hi Chris,

The series string is still 2700 ma-H - just like one of the
individual cells. The parameter that multiplies by the number of
cells is the energy capacity expressed in watt-hours. That’s 2.7
ma-H X 1.2 volts per cell =3.24 watt-hours per cell or 16.2
watt-hours for the five. Now that is a simplification. The actual
energy rating is a function of the current drain profile and works
out to be the area under the curve product of the current delivered
times the terminal voltage at any instant in time - over the time
it takes to discharge the battery down to some end of life terminal
voltage (where the voltage is dying fast).

The DPS8000 should have worked just fine - with much much more
capacity then what fits in the D7. Its five cells or six volts
which is more then you get from the cameras internal four cells and
2700 ma-H is much more then the 1800 ma-H capacity you can stick
inside the camera. Its likely there is a bad cell or a defective
charger.

The only reason for a Lithium Ion pack would be it's 7.2 volt
rating (for two cells in series). Normally the extra voltage would
only be wasted as heat but the D7's switching supply converts the
cells output efficiently to what the camera needs.

The reason the D7 does so poorly with its four cells is that its
low voltage shut down point leaves about 20% to 40% of the capacity
of the four 1800 ma-H cells unused because of the low voltage cut
off point. This is why the extra NiMH cell in series or the two
Lithium Ion cells do so much better then you would expect based on
just their ma-H capacity alone. The extra voltage makes it possible
to recover much more of the batteries capacity.

Pete

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Jim Underwood said:

Check tis review out:

http://www.steves-digicams.com/maha_powerbank.html

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Hi Jim,

Thanks - I checked it out and noticed a couple of things:

""This is a very nicely constructed battery pack that sells for just $53. I've tested out the Unity Digital ProPower Pack and the Mizco DPS-8000 and the Maha is easily their equal. This puzzled me because the Maha MH-DPB180M is a 6V NiMH (Nickel Metal Hydride) pack rated at 1800mAh whereas the other two are rated 2700mAh @ 6V. ""

Maybe the reference to 5/4 AA in the Digipower add copy was a typo. But it would have to be a gross one. I don't think you break 2000 ma-H with the AA variants. The next one up is AF and 5/4AF implies about 25% more then about 2500 ma-H or ~ 3100 ma-H. I don't know much about Steve's reviews - I don't see the hard evidence I would hope for (benchmarks in different cameras or run times under different constant current load conditions). But if his anecdotal comment is on the money, maybe it should be modified to say that the Maha is the equal of the Digipower because the Digipower is overrated. I guess that's what the quote from Dennis Thomas was in effect saying.

The other thing I'm hearing from Marty B and one other person is that the Digipower is much worse to no better then the best four cells you can stick right in the camera. That sounds like the other extreme and makes me wonder what factor conditioning plays and whether or not the Digipower charger can really top off their 8000 pack in the eight to twelve hours they claim. I suggested some voltages to check for as a reality check but rather then repeat the list, one worth mentioning is that you should see 1.5 volts per cell at full charge with the charger connected. The other is that the charger better have a no load voltage of better then 7.5 volts or they will never reach full charge.

There are a number of disconnects in what I'm hearing. I hope we can get to the bottom of it. All things being equal, with the D7 power section design, five series cells should be more then 25% better then four - and five bigger ones should be better yet - but it sounds like some are not seeing that.

Pete

Jim Underwood said:

Point taken. Here's something else to consider: the bull---- factor:

http://www.steves-digicams.com/maha_powerbank.html

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yes - maybe a bit too much fluff and kinda light on the real meat - like benchmarks in cameras or constant current drain load test results (and product to product comparisons) at different currents. But I appreciate the opportunity to read the review - thanks!

Pete

I've just made a battery holder that attatches to the camera itself instead of being remote.It will hold 6 NiMH 1.2V 1600MaH which gives 7.2V.From going through the other related posts I gather the D7 can handle this ok.What I'd like to know is,should the "in Camera" batteries be removed before plugging into a different power source? Any other advice before I hit the start button would be appreciated..

Tia..............Dave L.