DIY idea: external battery pack for D1X

[roygoh]

I have a couple of dead D1X batteries, so I took one of them, cut it open, and removed the internal NiMH cells. The metal contacts to the camera are still in tact, and I can run a pair of wires from the internal solder joints to to a DC jack that is mounted on the cover plate of the battery. That should allow me to power the D1X from an external battery pack or from an AC adapter that has 7.2V DC output.

If you are interested to know what the internals of the D1X battery look like you can go to here:
http://www.aljacobs.com/cabnikonD1.htm

For the external battery pack I found the following pack for radio control cars:
http://www.amondotech.com/index.asp?...ROD&ProdID=531

Only US$17.50 for a 7.2V NiMH pack with 3300mAH capacity!

The same site also sells a switch mode uP controlled charger for US$14.5.
http://www.amondotech.com/index.asp?...ROD&ProdID=709

Alternatively I can get one of the Sony InfoLithiums but that will cost a lot more (US$47.95 for 2200mAH NP-F570). The benefit is lighter weight and no memory effect though...

Any comments or suggestions?

Thanks!

Roy

[espn]

Get a D2X.


*espn runs away

[Nerd]

Hi Roy!

I feel that the connector on the battery pack is too small. Especially if the battery pack is capable of 20 amp current outputs. There might be a lot of resistance in the electrical joints of it's not done properly.

I always believe in over kill, thicker wires of higher purity, better solder quality, snug fitting precision connectors, especially in high current draw applications. So it might just be the kiasu side of me talking.

[roygoh]

Originally Posted by espn Get a D2X. *espn runs away

Roy pulls out sniper rifle and aims....

[roygoh]

Originally Posted by Nerd Hi Roy! I feel that the connector on the battery pack is too small. Especially if the battery pack is capable of 20 amp current outputs. There might be a lot of resistance in the electrical joints of it's not done properly. I always believe in over kill, thicker wires of higher purity, better solder quality, snug fitting precision connectors, especially in high current draw applications. So it might just be the kiasu side of me talking.

Hold on....the bottle neck is the miserable contacts between the battery casing and the camera. The camera definitely takes a lot less current than 20A so there is no need for the battery pack connector to be rated at such high currents. It's OK to be kiasu as long as there is at least some returns on the investment. In this case providing a 20A connection between the battery pack and the modified EN4 does not buy anything.

By the way the Tamiya connector is used for radio controlled cars so I think it has to be rated in terms of amperes, which is definitely adequate for D1X.

In fact I would probably add a 1A fuse inside the EN4 casing to prevent disasters.

[Ansel]

Roy,

Relating to this, do you think it may be possible to make an external batt pack out of 6 standard AA or AAA size NiMH batts in series? These batts can be taken out of the packs to charge in a standard charger.

Also, will it also work if we remove the spent cells out of original EN-4 casings and replace them by soldering 6 x AAA NiMH cells in their place?

[kahheng]

Originally Posted by roygoh Hold on....the bottle neck is the miserable contacts between the battery casing and the camera. The camera definitely takes a lot less current than 20A so there is no need for the battery pack connector to be rated at such high currents. It's OK to be kiasu as long as there is at least some returns on the investment. In this case providing a 20A connection between the battery pack and the modified EN4 does not buy anything. By the way the Tamiya connector is used for radio controlled cars so I think it has to be rated in terms of amperes, which is definitely adequate for D1X. In fact I would probably add a 1A fuse inside the EN4 casing to prevent disasters.

Good points Roy. I think Al Jacobs put down in the pic that the pack is able to give 20A simply because he's able to put that down. It's kinda superfluous info in this case.

20A is a massive load of current. Even my clothes dryer doesn't suck 20A!

[roygoh]

Originally Posted by Ansel Roy, Relating to this, do you think it may be possible to make an external batt pack out of 6 standard AA or AAA size NiMH batts in series? These batts can be taken out of the packs to charge in a standard charger. Also, will it also work if we remove the spent cells out of original EN-4 casings and replace them by soldering 6 x AAA NiMH cells in their place?

As long as the voltage is 7.2V it should work regardless of the battery type.

6xAA is doable but I was aiming for higher capacity, that's why I was tempted by the 3300mAH RC battery pack.

AAA batterys' capacity is too small to be useful (<1000mAH).

Some time ago I also came across a website which the owner made a battery pack out of 6x D cells. MAHA has a D cell that is rated at 11,000mAH!
http://www.zbattery.com/zbattery/mh-2d110.html

Also, keep an eye on Toshiba's latest Lithium Polymer "Super Charge" battery. They claim that it can be charged to 80% of its capacity in just 1 minute!
http://www.toshiba.co.jp/about/press/2005_03/pr2901.htm

[eawtan]

Some more D1 battery mods at : http://www.jknights.plus.com/JMK%20P...es/Page573.htm

Has a good step-by-step tutorial on opening the EN4 battery pack.

[kahheng]

Originally Posted by roygoh As long as the voltage is 7.2V it should work regardless of the battery type. 6xAA is doable but I was aiming for higher capacity, that's why I was tempted by the 3300mAH RC battery pack. AAA batterys' capacity is too small to be useful (<1000mAH). Some time ago I also came across a website which the owner made a battery pack out of 6x D cells. MAHA has a D cell that is rated at 11,000mAH! http://www.zbattery.com/zbattery/mh-2d110.html Also, keep an eye on Toshiba's latest Lithium Polymer "Super Charge" battery. They claim that it can be charged to 80% of its capacity in just 1 minute! http://www.toshiba.co.jp/about/press/2005_03/pr2901.htm

There's always a trade-off between weight and capacity. 6 D cells will weigh a fair bit more than a 7.2V RC racing pack and is also significantly more bulky. Besides 3300mah is already a lot more than the original D1x battery. How much do you need? (And if you need even more capacity, there are always larger capacity standard 7.2v RC packs)

What I like about the RC battery pack method is that they usually come ready done with a tail to hook up, all you need do is some very small mods to connect up to the system. Furthermore, good quality smart chargers for 7.2V nimh or nicads are always much more easily obtained than for any other voltage! ;-) How much life you get out of the battery is all dependent on the charger.

It's always a balance between cost, capacity, and effort to get it all done eh?

[kahheng]

Originally Posted by eawtan Some more D1 battery mods at : http://www.jknights.plus.com/JMK%20P...es/Page573.htm Has a good step-by-step tutorial on opening the EN4 battery pack.

Hmm, good link, good idea. Hmm, when my 1Ds batts die, I might yet do the Li-Ion mod. The weight of the camera is so much affected by the very heavy NIMH batteries.

[King Tiger]

roygoh, you should be a nuclear scientist.

[Ansel]

Originally Posted by roygoh As long as the voltage is 7.2V it should work regardless of the battery type. 6xAA is doable but I was aiming for higher capacity, that's why I was tempted by the 3300mAH RC battery pack.

6 x AA is already 2500 mAH with commonly available brands. The original EN-4 is only 2100 mAH. Charging can be done with standard AA chargers. That will do, until the cam dies on me.

BTW, you mentioned a 1.0 A fuse, do we connect it to the +ve end or -ve end, or does it matter?

[roygoh]

Originally Posted by King Tiger roygoh, you should be a nuclear scientist.

...I think that could have been my childhood dream but I ultimately ended up as a nerdy electrical engineer...

[roygoh]

Originally Posted by Ansel 6 x AA is already 2500 mAH with commonly available brands. The original EN-4 is only 2100 mAH. Charging can be done with standard AA chargers. That will do, until the cam dies on me. BTW, you mentioned a 1.0 A fuse, do we connect it to the +ve end or -ve end, or does it matter?

A fuse should not have any polarity, so you can connect it either direction.

If I go through the trouble of making an external battery pack I would at least shoot for a 50% increase in capacity.

Isn't 2500mAH AAs considered top of the line now? Anyway AAs are still the cheapest solution, lightweight, easy to charge and easy to replace. So they are definitely a good choice. If I really need more capacity I can always carry an extra set.

Latest charger from Sony - Ultra 15. This baby can charge 4x 2500mAH AAs in 15 minutes. Simply amazing....the charging current has to be 10A per cell to charge in 15 minutes. If there is a 0.1 ohm resistance in the contacts it will be generating 1W of heat.
http://www.zbattery.com/bcg-34hue.html

[Nerd]

Those so call 15 mins battery charger can only charge to 80% of the cell's capacity. It's always the last 20% that's the hardest and takes the longest to charge.

[Ansel]

Originally Posted by roygoh Latest charger from Sony - Ultra 15. This baby can charge 4x 2500mAH AAs in 15 minutes. Simply amazing....the charging current has to be 10A per cell to charge in 15 minutes. If there is a 0.1 ohm resistance in the contacts it will be generating 1W of heat. http://www.zbattery.com/bcg-34hue.html

Haven't seen the Sony on the local market, but the 15 min charger doing big marketing right now in Singapore is Varta, the German brand. They've got big bus ads going all over the country.

Now, with such high currents going thru the system, won't that be a serious cause for concern if anything goes wrong, like a short circuit or a failed cell, causing explosions, etc? Honestly, I think a 90 min charger is good enough for most practical purposes, plus the assurance of better safety.

Don't flame me, just IMHO.

[kahheng]

Originally Posted by Ansel Haven't seen the Sony on the local market, but the 15 min charger doing big marketing right now in Singapore is Varta, the German brand. They've got big bus ads going all over the country. Now, with such high currents going thru the system, won't that be a serious cause for concern if anything goes wrong, like a short circuit or a failed cell, causing explosions, etc? Honestly, I think a 90 min charger is good enough for most practical purposes, plus the assurance of better safety. Don't flame me, just IMHO.

I think a 15min charger would be good for people who often forget to charge their batteries and they need to use their devices in a hurry. This would be the bulk of 'home' users who are not hobbyists. Many of my digicam using friends are like this. So I think these high speed chargers are a good idea. The hilarity comes when some idiot puts in Nimh batteries not designed for such high current charging!

Unfortunately, a lot of nice digicams these days DON'T use AAs anymore ;-)

Like yourself, a regular 'fast' charger is good enough for me. I have so many AA chargers that I can't actually use them all unless I start accumulating a lot of AA powered devices again.

[roygoh]

The 15 min chargers require a larger and separate power supply (at least true for the Panasonic 15 min model I saw in the store today), so they are not really portable. The thing is I will most likely need the fast charging when I am travelling, so there is a little conflict here.

When I am not travelling my 60 min charger from Sony is just fine. Got that in Japan, and it comes with the refresh function.

I think I am leaning towards reusing the battery pack I made for my CP995. Just need to modify the battery case I extracted by adding a suitable DC jack for connectin to my existing battery pack.