Hi all
I need help with a concept i have been working on Please - my understanding of electronics is very basic (non exsistant)
I want to make a simple Solar 1.5 V AAA battery charger. Emphasis is on size + weight.
just 1 single AAA li-ion rechargable battery charged by (i am thinking ....) 2 of those little solar powered calculator solar strips (ave 3.6Vdc @ 1.5 Watts Max)
in my mind the unit would be tiny-like a Tic-tac Container(60x35x15mm-fits 3x AAA batt) - or even smaller, to just charge a single AAA battery - it would come in very handy when camping
theres always a "flattest" battery in my bunch - with this i could solve the problem by just leaving it on a rock in th sun at my camp ,while I enjoy my day. charger working quietly...
When i get back to camp - my flat battery is fully charged.YAY!!
A standard AAA battery charges @ 2.8Vdc with 120 - 150 mA - says so on the back of my normal Energizer Mains powered AA / AAA Charger
In a perfect world I would love if it could also charge an AA battery ,but at 2.8Vdc with 260-300mA - i dont think 2 solar calc strips will be enough - again from the back of my Energizer mains Charger - its max power use is 8 Watt - with 4 AA batteries in - im plan on using 1 x AAA
I live in South Africa - Cape Town. Here we have almost cloudless days for about 9 months of the year - ive found info that states :960 watts per squre meter is what the sun puts out on a sunny day - a calculator solar strip(12% efficiency) is about 1 square inch = 1.58 Watts - WE GET FULL SUN HERE ....
A friend suggested just wiring the 2 solar strips in parallel ,connecting the battery in parrallel with these + a 5K / 10 K resistor to limit current (in series on the Positive....right??) this seems viable, but very "bushmechanic" like to me
Should there maybe be a 2.8V diode (zener?) in series with the resistor - to limit the voltage as well?
would this work - or is the resistor size wrong? to little power from 2 strips?
Also - what sort of power (heat) would the resistor + diode have to deal with?
Small + cheap + hopefully very easy to make - a usefull addition to any campers gear / "bug out" bag
adding a third solar strip is viable - if needed - just makes the unit a bit bigger possibly - not preffered...
Hopes this gives some people ideas..
thanx in advance
I need help with a concept i have been working on Please - my understanding of electronics is very basic (non exsistant)
I want to make a simple Solar 1.5 V AAA battery charger. Emphasis is on size + weight.
just 1 single AAA li-ion rechargable battery charged by (i am thinking ....) 2 of those little solar powered calculator solar strips (ave 3.6Vdc @ 1.5 Watts Max)
in my mind the unit would be tiny-like a Tic-tac Container(60x35x15mm-fits 3x AAA batt) - or even smaller, to just charge a single AAA battery - it would come in very handy when camping
theres always a "flattest" battery in my bunch - with this i could solve the problem by just leaving it on a rock in th sun at my camp ,while I enjoy my day. charger working quietly...
When i get back to camp - my flat battery is fully charged.YAY!!
A standard AAA battery charges @ 2.8Vdc with 120 - 150 mA - says so on the back of my normal Energizer Mains powered AA / AAA Charger
In a perfect world I would love if it could also charge an AA battery ,but at 2.8Vdc with 260-300mA - i dont think 2 solar calc strips will be enough - again from the back of my Energizer mains Charger - its max power use is 8 Watt - with 4 AA batteries in - im plan on using 1 x AAA
I live in South Africa - Cape Town. Here we have almost cloudless days for about 9 months of the year - ive found info that states :960 watts per squre meter is what the sun puts out on a sunny day - a calculator solar strip(12% efficiency) is about 1 square inch = 1.58 Watts - WE GET FULL SUN HERE ....
A friend suggested just wiring the 2 solar strips in parallel ,connecting the battery in parrallel with these + a 5K / 10 K resistor to limit current (in series on the Positive....right??) this seems viable, but very "bushmechanic" like to me
Should there maybe be a 2.8V diode (zener?) in series with the resistor - to limit the voltage as well?
would this work - or is the resistor size wrong? to little power from 2 strips?
Also - what sort of power (heat) would the resistor + diode have to deal with?
Small + cheap + hopefully very easy to make - a usefull addition to any campers gear / "bug out" bag
adding a third solar strip is viable - if needed - just makes the unit a bit bigger possibly - not preffered...
Hopes this gives some people ideas..
thanx in advance
Last edited: