gawd: rechargeable D batteries are expensive

[desura]

Looking at a min $50 for a rechargeable D battery setup.

Charger is like 20-25

batteries are about 5 bucks each.

Anyone know where to get these things cheaper?

 

[gorcorps]

D batteries aren't special except for capacity (same voltage as AAA and AA). They sell D-size shells that you can put AA rechargeables in if you want to try that route.

 

[phucheneh]

I believe you can get adapters that let you load AA's into a D housing...call it the 'WonderBat,' perhaps. :hmm:

D is still 1.5v, so one AA battery, or two or more in parallel, will run the same device. The smaller batteries just have less capacity.

 

[desura]

D batteries aren't special except for capacity (same voltage as AAA and AA). They sell D-size shells that you can put AA rechargeables in if you want to try that route.

...and AT saves the day! tyvm. I hadn't thought of that!

 

[shortylickens]

Yup. And not as useful as they have been in the past. Most modern gadgets that require such power have been using custom Li-ion cells.

 

[exdeath]

CR123 Lithium or go home

 

[jagec]

I believe you can get adapters that let you load AA's into a D housing...call it the 'WonderBat,' perhaps. :hmm:

D is still 1.5v, so one AA battery, or two or more in parallel, will run the same device. The smaller batteries just have less capacity.

Much, much less capacity.

How much voltage are you looking for? The cell voltage for LiFePO4 is 3.3V (just a bit above 2 alkalines in series) and that's with a VERY flat discharge curve and abuse-tolerant chemistry.

If you're going to put a smaller NiMH or NiCd battery in a D shell, at least get Sub C's.

 

[desura]

Much, much less capacity.

How much voltage are you looking for? The cell voltage for LiFePO4 is 3.3V (just a bit above 2 alkalines in series) and that's with a VERY flat discharge curve and abuse-tolerant chemistry.

If you're going to put a smaller NiMH or NiCd battery in a D shell, at least get Sub C's.

Yeah, just realized that too. D cells can be from 5000 to 10000 capacity.

AA's are like 2500 at best. 1/4th that.

I've been thinking lately...it shouldn't be that hard to get like a portable rechargeable outlet for any electronic, no? Basically, like take a laptop battery cell, put it in a box, connect it to power outlet. Recharges when plugged in. Gives power when unplugged and has power drawn from it.

 

[jagec]

Yeah, just realized that too. D cells can be from 5000 to 10000 capacity.

AA's are like 2500 at best. 1/4th that.

I've been thinking lately...it shouldn't be that hard to get like a portable rechargeable outlet for any electronic, no? Basically, like take a laptop battery cell, put it in a box, connect it to power outlet. Recharges when plugged in. Gives power when unplugged and has power drawn from it.

Li-Ion needs proper control circuitry to charge without catching on fire. In the case of the laptop, it is built into the motherboard.

 

[TastesLikeChicken]

Get a smaller vibrator. AA rechargeables are cheaper.

 

[MontyAC]

Go buy them from Costco.

 

[Fritzo]

Get a smaller vibrator. AA rechargeables are cheaper.

 

[Red Squirrel]

How much voltage do you need? If it happens to be 12 volts a small gel cell will be cheaper and have higher capacity and unlimited charges. Dry cells have limited charge cycles, so it's something to consider too if you're paying that much.

You can also use AA's as suggested but if the reason you need that many D cells is for capacity and not voltage then it sorta defeats the purpose.

At church we have a lapel mic that occasionally a preacher will ask for. Almost every time we go to use it the batteries are dead. One time I was in a pinch and could not find AA batteries for it but found two AAA's. I found two small screws lying around and manage to lodge the AAA's with the screw so that it makes contact. It actually worked for the whole service. I was pretty sure it would end up working itself loose or something.

 

[desura]

okay, it's actually for a portable fan. Hey, it's summer, it's hot, and being able to just carry around a fan anywhere around the house is the idea.

I ended up doing the AA + D spacers because I already have a pretty good AA charger, and like reviews for the fan say that with D batteries it can last like 2 days straight, so with AA's I can probably expect at least half a day, which is enough.

 

[Jeff7]

How many batteries does it take?



Oh man...old memories just stirred, of using a 120mm Panaflo computer fan and a lead acid battery, for a similar purpose.

 

[CurseTheSky]

CR123 Lithium or go home

I've heard some bad stories about running them in series in certain devices. IIRC, it's mostly related to mixing brands or mixing drain levels, but still.

With that said, they're teh secks for anything that needs to be niiiiice and bright.

 

[desura]

How many batteries does it take?



Oh man...old memories just stirred, of using a 120mm Panaflo computer fan and a lead acid battery, for a similar purpose.

haha, I briefly considered like trying to rig together like a car battery and a fan but...eh...

And while 120mm panaflo is big for a computer, for a person it's kinda small, isn't it?

But it takes six D batteries. Which would have been at least $30 plus $25 for a D charger. Just too much.

 

[Red Squirrel]

For a fan I'd definitely go the gel cell route. Cheaper in the long run. Try to find a 13.5v adapter so you can plug it in every now and then to charge it and use at same time. Replace 13.5 with whatever is the recommended float voltage of the battery you get. For flooded cell it's 13.5 but think gel cells need a bit higher.

There's a place here that will sell a gel cell for like 20 bucks. Check local electrical supply stores you should be able to get a decent deal on one. Something that is equivalent to a UPS battery.

 

[phucheneh]

6 x 1.5 = 9v. Assuming they're all stacked in series.

Does this device actually NEED batteries, or would you plug it in if you could? Depending on the current drawn by the fan, a 9v brick may be pretty easy to find. Definitely easy to wire in.

 

[disappoint]

CR123 Lithium or go home

18650s will send those puny CR123s crying home to mommy.

 

[exdeath]

18650s will send those puny CR123s crying home to mommy.

Same difference, same class of cell vs primitive AA, C, D, etc.

Most devices in that class can use 2x CR123 or one 18650 while you have the option for micro size devices like the 170 lumen Fenix E15 that's not even 2" long. Besides 18650s don't fit in Eotechs :awe:

 

[Gillbot]

http://www.harborfreight.com/catalogsearch/result?q=rechargeable+D

 

[W.C. Nimoy]

OT but just curious if there is such thing as a lithium primary D-cell?

 

[Imp]

Only D cells I have is for my Maglite and it's an LED so hasn't required a change in years. I wonder how long a 6D LED Maglite would last...

I'm surprised that no standard has been made for lithium-ion batteries so that every device doesn't need their own custom, proprietary battery.

 

[shortylickens]

Only D cells I have is for my Maglite and it's an LED so hasn't required a change in years. I wonder how long a 6D LED Maglite would last...

I'm surprised that no standard has been made for lithium-ion batteries so that every device doesn't need their own custom, proprietary battery.

I have a 6D and put in the LED upgrade. Something happened and it died in 6 months. Never did get any support from the company.