View Full Version : How many D cell batteries would you need to replace a 6V 4.5Ah battery?
tomwise
May 9, 2013, 08:53 AM
How many D cell batteries would you need to replace a 6V 4.5Ah battery?
I'm trying to make a power comparison and not physically make the replacement. Would you suggest a different battery to compare the 6V 4.5Ah battery to?
Thanks
Tom
smoothy
May 9, 2013, 09:19 AM
YOu are aware you are very specific of the type and capacity you want to replace (hypothetically)... then toss our a very unspecific generality like "D" cell .
Are we taling Alkiline, Ni-Cad, Lithium-Ion, etc, etc?
tomwise
May 9, 2013, 09:55 AM
Hi Smoothy
Thanks for your reply.
I'm thinking standard carbon-zinc D battery.
Here's what I'm up too:
I sell an item on HSN called the What-A-Light!
What-A-Light! Portable Rechargeable Fluorescent Lamp at HSN.com (http://www.hsn.com/products/what-a-light-portable-rechargeable-fluorescent-lamp/4705638?query=What-a-light&isSuggested=False)
It's powered by a rechargeable 6V 4.5Ah battery lead acid battery.
At some point in the presentation I'd like to say "the battery inside the WAL! can be recharged up to 300 times. That would be the equivalent to buying _?_ hundred D cell batteries!"
I'd like to know the number of D batteries it would take to power the WAL!
Thanks
Tom
smoothy
May 9, 2013, 10:14 AM
Here is a good place.. that gives a lot of that info...
Battery Capacity (http://www.techlib.com/reference/batteries.html)
Also its still not quite as simple as that... as that's an AGM type battery... and not really suitible for deep discharging... meaning the deeper its discharged... the shorter its lifespan.
That 300 recharge lifespan is based on some unknown assumption.
tomwise
May 9, 2013, 10:22 AM
Thanks]
smoothy
May 9, 2013, 10:25 AM
Just remember in series.. the battery output stays the same as a single but the voltage increases... in parallel the voltage tays the same but the current increaces.
You would have a pack that's 4 deep in series (4 x 1.5v =6v)... but X in parallel both to get the needed current.
tomwise
May 9, 2013, 10:39 AM
Very good. So I'd be in the ball park to say you'd need 4 D cell batteries to turn the light on?
Thanks again smoothy.
smoothy
May 9, 2013, 10:58 AM
4 gets you 6 volts at the current a single D-cell will provide.
you multiple those 4 cell groups side by side (parrallel) to now get the current that the AGM battery provided... but you will be needing more than 4 D cells.
Remember since a D cell is rated at 0.2 aH (200ma) and your battery needs to be 4.5 aH to match it...
Basically 4.5 ÷ 0.2 = X (the number of 4 cell groups you need)
Being that's fluorescent... the startup current is higher than the run current... so not sure if 4 will get it to light... but they certainly wouldn't last long if it did.
tomwise
May 9, 2013, 11:20 AM
Very interesting.
Thank you.