Battery adapters

[Poppy]

Post pictures of battery adapters you bought, 3D printed, or built.

This one should arrive today.
It is an adapter for Ryobi One+ 18V batteries.

https://www.amazon.com/gp/product/B09B2KB8RN/?tag=cpf0b6-20

 

[orbital]

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Whatcha going to make or run with that 18V DC Poppy?

...small Anderson connectors are very nice to work with.

https://www.amazon.com/dp/B07SCYY1NC/?tag=cpf0b6-20

 

[Poppy]

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Whatcha going to make or run with that 18V DC Poppy?

...small Anderson connectors are very nice to work with.

https://www.amazon.com/dp/B07SCYY1NC/?tag=cpf0b6-20

I'm hoping that I don't burn out this little 12V pump with it.

DC 12V self-priming diaphragm pump Micro water pump, 2LPM 15PSI suitable for water dispenser/ice maker/cooler/small pumping projects - - Amazon.com

DC 12V self-priming diaphragm pump Micro water pump, 2LPM 15PSI suitable for water dispenser/ice maker/cooler/small pumping projects - - Amazon.com

www.amazon.com

A hot dog cart is like a mobile chafing dish that uses propane to boil/heat water, that in turn heats condiments (chili, sauerkraut, cheese, etc). My son sometimes needs more heated compartments. He nearly maxed out that 2K gennie on Saturday, running a 40 cup coffee urn, and crock pot.

I plan to pump heated water into a cooler, which will act like an insulated chafing dish, and have an overflow tube set at the proper height, to return the water to the heated tank. The pump will circulate the heated water when needed. I could get fancy and install a temperature activated switch, but first we'll have to test the concept.

 

[orbital]

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Doubt you'll burn out the little pump, 99% sure it'll just run faster.

 

[Poppy]

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Doubt you'll burn out the little pump, 99% sure it'll just run faster.

I agree, thanks for your vote of confidence 🙂

 

[idleprocess]

I have a small fleet of 3xAA : D parallel adaptors, ala:

Handy for powering D-cell appliances with LSD NiMH cells.

 

[Lynx_Arc]

Personally I would caution against running a 12vdc pump off of what is likely 20.5vdc off the charger for 18v and 20v lithium ion batteries. I would suggest a simple solution of calculating a resistor to burn off the excess voltage figuring on getting rid of about 7-8vdc or I would instead consider using a 24V pump instead.

 

[Poppy]

Personally I would caution against running a 12vdc pump off of what is likely 20.5vdc off the charger for 18v and 20v lithium ion batteries. I would suggest a simple solution of calculating a resistor to burn off the excess voltage figuring on getting rid of about 7-8vdc or I would instead consider using a 24V pump instead.

I was thinking that it might be wise to put a resistor in line but I don't know what size.

 

[orbital]

I was thinking that it might be wise to put a resistor in line but I don't know what size.

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It's spending another $10, but this is 15-40V input ~ 12V output at 5A
I'v personally used the brand

https://www.amazon.com/dp/B08R74T22D/?tag=cpf0b6-20

 

[xxo]

A few of my mine:

 

[Poppy]

Thank you orbital, I'll certainly consider it.

 

[snakebite]

just one type i print.

 

[Poppy]

snakebite, and xxo, would you please consider describing your adapters, which ones convert what to what?
Some are obvious, and others, not to obvious to me.
Thanks.

You guys are much more talented than I. 🙂

 

[xxo]

snakebite, and xxo, would you please consider describing your adapters, which ones convert what to what?

On the left side of the Maglite, the skinny white adapter is a 2 AA to 2 AAA, it fits in the blue spacer which when used by itself allows 2 AA's to run a 2 C cell light. The red adapter is a 21700 to 2C adapter.

On the right, the blue adapter is 18650 to 2C. The white adapter is 14500 to 18650 which is used inside the blue 18650 to 2 C adapter. The black adapter is a CR123A/16340 adapter, that also works in the 18650 to 2C adapter.

All of the 2 C cell adapters can be used in a 2 D light inside the red 2 C to 2 D adapter in the center of the photo. Since a 2 D cell light will also fit a 26650, the red adapter on the far left is for that.

 

[snakebite]

the one in the pic is 2d to 18650.
i also make one similar for 21700.
the fridge light has a 3.6v 900ma "xenon plus" bulb.
just remember to select proper bulb/led for your setup.
and make sure led lights like the mag are ok with it.

 

[Poppy]

xxo,
Thank you for the explanation! All of the possible variations are impressive. It must have taken a lot of math calculations to make them all work together.

snakebite,
Your's too is impressive. Lots of work to make connections at both ends of the adapter.

 

[Lynx_Arc]

I was thinking that it might be wise to put a resistor in line but I don't know what size.

I think that was a motor 12v 0.4A. A resistor that is dropping 8v at 0.4A using ohms law R=E/I which makes for 8/0.4 or 20 ohms. Then you need to calculate the wattage of 8v times 0.4A or about 3.2 watts, I would use 4 or 5 watts better to have a higher than needed wattage of resistor as more than needed doesn't do any harm. If you use higher ohms it will reduce the voltage to the motor more and lower ohms will have it higher. It is likely the motor/pump could handle 20% more than it is rated at so it may be fine up to 14-15v making you only needing to drop 5-6v at 0.4A which would make for a 12.5 to 15 ohm resistor of 2-3 watts. If you have resistors in this range you can use wiring them in series/parallel to get the voltage you need. Another better solution IMO would be to get a buck circuit module that can handle 24vdc as you could dial in the right voltage and it would be a lot more efficient converting the excess voltage into current which would increase the run time off a battery source. Resistors usually are a lot cheaper if you have them already or can source them locally.

 

[Poppy]

I think that was a motor 12v 0.4A. A resistor that is dropping 8v at 0.4A using ohms law R=E/I which makes for 8/0.4 or 20 ohms. Then you need to calculate the wattage of 8v times 0.4A or about 3.2 watts, I would use 4 or 5 watts better to have a higher than needed wattage of resistor as more than needed doesn't do any harm. If you use higher ohms it will reduce the voltage to the motor more and lower ohms will have it higher. It is likely the motor/pump could handle 20% more than it is rated at so it may be fine up to 14-15v making you only needing to drop 5-6v at 0.4A which would make for a 12.5 to 15 ohm resistor of 2-3 watts. If you have resistors in this range you can use wiring them in series/parallel to get the voltage you need. Another better solution IMO would be to get a buck circuit module that can handle 24vdc as you could dial in the right voltage and it would be a lot more efficient converting the excess voltage into current which would increase the run time off a battery source. Resistors usually are a lot cheaper if you have them already or can source them locally.

I was out getting my covid booster shot today, and on the way back, I stopped by an electronics shop and asked for a resistor. He recommended a voltage regulator. I asked... "what will that be? About $10?" He replied... "Nah... $3."
Here it is.

@Lynx_Arc, I really appreciate you, for taking your time to do the math, and explaining it along the way.
Thank You.
Poppy

 

[Lynx_Arc]

I was out getting my covid booster shot today, and on the way back, I stopped by an electronics shop and asked for a resistor. He recommended a voltage regulator. I asked... "what will that be? About $10?" He replied... "Nah... $3."
Here it is.

View attachment 20169

@Lynx_Arc, I really appreciate you, for taking your time to do the math, and explaining it along the way.
Thank You.
Poppy

Yes, a voltage regulator can be used that would allow you to use a wider range of input voltages without noticing output voltage drop that a resistor would have. Beware that unless your battery pack has built in voltage protection (I think most do but some may have the protection built into the tools itself I'm not totally sure) you could drain it below safe levels.
You may need to add a heat sink as you will have the regulator essentially burning off the excess voltage at the 0.4A rate or about 8v times 0.4A making 3.2W of power wasted off a 20v (max 18v nominal) battery pack. A buck regulator would be a lot more efficient wasting a small fraction of that. They use buck regulators and linear (voltage regulators) in lights for similar reasons.

 

[orbital]

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Lynx_Arc, I'v noticed in several threads (really all of your posts) you go above & beyond on thorough explanations.
Gold Star to you!!👍👍