Reddit mentions: The best d batteries

They look similar because this iPod enabled boombox is actually a modern remake of the Lasonic TRC-931 Cassette Boombox. While they look very similar the original is said to have much better bass response.. I've owned one of the newer models that are made for iPods and despite its shortcomings compared to the older cassette tape version I'd say it's a well worth the money if a boom box is something you're interested in.

However I would recommend purchasing some rechargeable D batteries and a charger if you want to fully utilize the boombox greatness.

Here's the specs sheet for the cells used in this battery.

You are right, they are basically NiCad D cells.

EDIT: And in Amazon, you can buy a 12 pack of NiMH D batteries with a capacity of 10 amp-hours for about 70 American dollars. That is going to make a dent on your pocket, but hey, if the hack job is successful, you'll end up with better battery life than with the stock battery. Now if only if they made lithium-ion batteries at D size...

If you have old incandescent Maglites, you can get LED bulb upgrades for them. But Maglite also makes LED flashlights. (Caution, affiliate links.) Their latest generation is actually pretty good. Somewhere on youtube is a video of a guy dropping rocks and stuff on a 3rd gen model and it never stops glowing. If you like the Maglite shape and weight they are the only^ people making decent D-cell flashlights.

Old or new Maglite, I would recommend getting NiMH batteries for them. Those batteries may look expensive but a single D cell holds as much power as a four pack of Eneloops, so they are actually a good deal.

^ Fenix used to have several but that's been scaled back to the TK50 and TK60. Both sell for around $100.

Supposedly the fuel cell's "chemical energy is stored without loss indefinitely."

edit for comparison: One minipak fuel cell can apparently hold about 5 AA batteries worth of Wh (watt-hours) or a little more than a C battery).

If you really want a battery that lasts a looong time I think your best bet is a D-cell Lithium-Thionyl Chloride battery. This feller has about 3.5 times the Wh of a regular alkaline D-cell, which makes it last about 35 times as long as an alkaline AA.

Check out these Tenergy LSD NiMHs. Lots of guys run these in modified Mags that require a very high current draw. With the LED that comes stock in your Mag, you might actually get better run time from the Alkalines but if you ever decided to upgrade the emitter or just want the option of rechargeables, these Tenergy cells are top notch.

Cheers

Yes, what you're describing is very possible; it is called a battery/power management system. However, using D-cell batteries is probably not a great option here.

I'm using you're using these batteries.. These are more geared towards consumer user than with easy integration into a DIY project.

Is there a reason you chose a 12V/3A supply?

Adafruit has some easy components/solutions you could look into.

See:

Lithium Ion Battery Pack - 3.7V 6600mAh

https://www.adafruit.com/product/259

I would love https://www.amazon.com/dp/B0148675ZO pack of 8 rechargeable batteries or 6 or 4 pack, or the techkewl packs! Gimme some Tech Daddi!

Road pro d cell powered fan https://www.amazon.com/RoadPro-RP8000-Indoor-Outdoor-Power/dp/B00KJGRLJI/ref=sr_1_1?ie=UTF8&qid=1526014405&sr=8-1&keywords=roadpro+fan
powered with a couple sets of these D Cells https://www.amazon.com/Tenergy-10000mAh-Rechargeable-Batteries-Flashlight/dp/B001AYIRH8/ref=sr_1_sc_1_a_it?ie=UTF8&qid=1526014459&sr=8-1-spell&keywords=ternergy+d+cells

Charge them with this charger
https://www.amazon.com/Tenergy-T-1199B-Universal-Battery-Charger/dp/B0019273U8/ref=pd_bxgy_121_img_2?_encoding=UTF8&pd_rd_i=B0019273U8&pd_rd_r=6AKQTFQM053GGVEPMPC4&pd_rd_w=f0PUk&pd_rd_wg=S4GRX&psc=1&refRID=6AKQTFQM053GGVEPMPC4&dpID=41pRtqenYEL&preST=_SX300_QL70_&dpSrc=detail

Charge up at the local libraries
that setup should power the fan for a few days on high per set of batteries.

These EEMB D Lithium Batteries would work great.
https://www.amazon.com/EEMB-lithium-battery-Powerful-ER34615/dp/B075ZPXG6M/ref=sr_1_4?s=electronics&ie=UTF8&qid=1511344362&sr=1-4&keywords=d%2Bsize%2Blithium%2Bbattery&th=1

If you want to go full retard, grab a Fenix TK70 while you still can. They have been discontinued by Fenix, but you can still get them new. At Amazon.com, they are about $210.

Goinggear.com has a garage sale where they are currently selling 2 at $120 each. This is a steal for this light. I have one and my friends refer to it as my Tactical Plunger, because it is so massive and has the shape of a plunger. It has a massive head, takes 4 D cell batteries, outshines almost every light on the planet in the distance category, and is just fantastic in every way. To take full advantage of it, you have to use NiMH D cells. This means that you will have to invest in rechargeable D cells and a battery charger. It can run off regular D cells, but they will drain quickly and it will not stay on turbo mode due to the high drain that alkaline D cells simply cannot handle. If you decide to go this route, here is the link for the $120 sale, as well as links to the batteries and charger you should buy for it.

http://www.cpfmarketplace.com/mp/showthread.php?284550-GoingGear-com-Garage-Sale-2013

http://www.amazon.com/Tenergy-Centura-Self-Discharge-LSD-Rechargeable-Batteries/dp/B0041TEHMS/ref=sr_1_1?ie=UTF8&qid=1375876288&sr=8-1&keywords=tenergy+centura+d

http://www.amazon.com/Tenergy-T-9688-Universal-Battery-Charger/dp/B002FKNPBY/ref=pd_sim_e_5

Make sure you get low self discharge NiMH D cells like the ones I linked you. They have less capacity, but they can sit for years and only lose a small amount of their charge. While the regular NiMH D cells have 10000 mAh capacity vs 8000 mAh in the low self discharge variant, you will regret buying the regular ones because they lose their charge VERY quickly....like you will have to recharge them every week even if you don't use the light.

If you do not want to spend this kind of money, I would go with srs2000's recommendation of the Defiant ArmorMax 3D Tactical Flashlight posted in this thread. They are much better than Maglites in my opinion and are also much brighter.

The Odyssey+ is great for seated VR. It's the most comfortable headset I tried so far (with the VRCover, it's terrible without it). The high-res displays make text readable in elite dangerous (comparable to the Rift S) and the contrast, lack of SDE and bigger FOV are great for sim racing.

To address some of the mentioned issues:

You don't need to use the WMR software after you set up your tracking space. Install MixedReality for SteamVR and SteamVR and just use that.

The bad tracking reports come mostly from people that use headsets without built in bluetooth or the wrong batteries.
The voltage drop in normal batteries decreases the tracking accuracy and stability for WMR controllers.
Make sure you use rechargeable Lithium-ion batteries (like these) and you will hardly even notice a difference in tracking between Rift S and O+ in most games. Rift S tracking is definitely better in some situations, but the issue is overblown.

Controllers being worse is also debatable, both have their pros and cons. Most would likely prefer the touch controllers, but the O+ controllers aren't much off and miles ahead of something like the Vive controllers.

I find Text readability is on par with the Rift S, but both display text differently.
The Rift S displays text sharper, but more pixelated than the O* (A bit like this)

it is probably a proprietary case, but if you take it apart it is made of individual cells that you can replace the cells, from the size they may be D size, or sub C... something like this might work.

Rather than buying normal D cells, consider rechargeable D-cells.

You'll pay more up front for them but it will pay off over time.

Something like this:

http://www.amazon.com/Powerex-cell-000mAh-Rechargeable-Batteries/dp/B0002LR50A - perhaps not necessarily this exact package, but try to get 11000-12000 mAh cells.

You need a charger too, so maybe this: http://www.amazon.com/Tenergy-Advanced-Universal-Charger-TN190-4/dp/B006OSQALU/ref=pd_cp_ba_1

My entire build is based around USB so it's all interchangeable in whatever configuration I want. Solar is currently a powerfilm lightsaver, but I'm going to upgrade that soon as it can't handle the 1 amp draw of the USB charging cable for the yaesu.

AAA's are smaller then AA's. (think like the little shits you put in your TV remote.) My flashlights are 18650, and I can charge them via the solar charger, or use them as power banks to recharge other stuff. The AAA's I use have microusb ports in them and are lion as well, so I can charge them off the nitecore, or direct from solar.

https://www.amazon.com/Rechargeable-Batteries-Charging-Quick-Charge-Fuvaly/dp/B07QW531W2

I'm considering getting either:
https://www.amazon.com/Combo-Tenergy-5000mAh-Rechargeable-Batteries/dp/B009WTK3DY/ref=sr_1_14?ie=UTF8&qid=1541525875&sr=8-14&keywords=rechargeable+D+battery
or
https://www.amazon.com/Combo-Rechargeable-Batteries-Capacity-10000mAh/dp/B00408IF1Y/ref=sr_1_13?ie=UTF8&qid=1541525875&sr=8-13&keywords=rechargeable+D+battery#customerReviews
Just wondering if it would burn anything out.

Haha, some of these are probably a scam and the Eveready won't last an hour, but look at Amazon..

These

or these

I thought it was odd that he was harping on how many mAh the "bad" D battery held and that it was the same as a AA but he never did say how many mAh a D size is supposed to have.

Some googling found these:

Rechargable D size @ 12,000 mAh, 2 for $23.

http://www.amazon.com/CTA-Digital-12000-Rechargeable-Battery/dp/B001647WKU/ref=pd_sbs_hpc_1

8 pack for $50 @ 10,000 mAh:

http://www.amazon.com/Tenergy-Size-capacity-Rechargeable-batteries/dp/B001AYIRH8/ref=pd_sbs_hpc_3

Cant find the exact battery, but a like-for-like replacement may be an option? The following are the same voltage and capacity, but in a standard D cell shape, the listing indicates suitable for utility meters.

http://www.amazon.com/OmniCel-ER34615-Lithium-Battery-Leads/dp/B005XA028C/

Disclaimer: Not an electrician. :)

You can get other brand low self discharge NiMH batteries in larger sizes: http://www.amazon.com/Tenergy-Centura-Self-Discharge-Rechargeable-Batteries/dp/B0041TEHMS

Maglite with a Malkoff drop-in?

Malkoff

Maglite

Batteries

I want something similar myself, but I'm converting a 4D Maglite into a 4000K 90CRI Triple.

I typed out this post then noticed your length requirement, sorry!

Too bad they don't make rechargeable D cells anymore.

Edit: Okay, I was wrong.

But I can go to the dollar store and buy Enerjizzer or Duraspell batteries in AA size that don't provide as much life as other brands of AA battery.

In the end, I do get the point; non rechargeable size D batteries should be 20500 mA.H, but even the ones labeled "high capacity" on Amazon don't do that. Other companies are doing the same thing as Energizer, with low capacity D sizes.

I bought these bad boys and a charger