Hi,
Just thought I'd pick peoples brains about a little problem I have.
I have designed a system that runs on batteries for a customer, great battery life, but to save them money on alkaline ones, they want to use rechargables. Thats fine since the circuit uses a LDO regulator for 3.3v, so any almost any battery type can be used (3*AA's).
However, since the system is sealed for an industrial enviroment, they don't want to open up the box to take the batteries out for recharging, so most stock of the shelf jobs are out. Therefore, I am left with two options:
1. Retrofit a small charging circuit inside the box. Would take in power from a plug-in DC power supply (simple regulated job) via a DC jack, control the charge, and provide indication of 'fully charged' via LED.
2. Somehow, provide an external circuit (also powered by a wallwart type thing) that can charge the batteries inside. Less crap to go into the box, and few circuits to build, as they only need two chargers, for 8 units. This could have 'charged' indication either inside the box (signal provided by the external charger, LED inside the box) or on the plug itself, as I've modified DC plugs before to include tricolour LED's.
Now, as you can tell, I'm not overly keen on option one, its more work, more hassle, but I do realise that charger circuits are generally 'in-system' since they need to closely monitor the batteries' voltage/temperature.
I don't have much experience with building battery chargers from scratch, and this has to be something that does not require batteries to be put into it, so I've come here. I believe they wish to use Ni-MH, as opposed to Li-ion, and charging time is not that urgent, preferably under 8 hours.
Any suggestions/experiences/links/advice are welcome.
Blueteeth
Just thought I'd pick peoples brains about a little problem I have.
I have designed a system that runs on batteries for a customer, great battery life, but to save them money on alkaline ones, they want to use rechargables. Thats fine since the circuit uses a LDO regulator for 3.3v, so any almost any battery type can be used (3*AA's).
However, since the system is sealed for an industrial enviroment, they don't want to open up the box to take the batteries out for recharging, so most stock of the shelf jobs are out. Therefore, I am left with two options:
1. Retrofit a small charging circuit inside the box. Would take in power from a plug-in DC power supply (simple regulated job) via a DC jack, control the charge, and provide indication of 'fully charged' via LED.
2. Somehow, provide an external circuit (also powered by a wallwart type thing) that can charge the batteries inside. Less crap to go into the box, and few circuits to build, as they only need two chargers, for 8 units. This could have 'charged' indication either inside the box (signal provided by the external charger, LED inside the box) or on the plug itself, as I've modified DC plugs before to include tricolour LED's.
Now, as you can tell, I'm not overly keen on option one, its more work, more hassle, but I do realise that charger circuits are generally 'in-system' since they need to closely monitor the batteries' voltage/temperature.
I don't have much experience with building battery chargers from scratch, and this has to be something that does not require batteries to be put into it, so I've come here. I believe they wish to use Ni-MH, as opposed to Li-ion, and charging time is not that urgent, preferably under 8 hours.
Any suggestions/experiences/links/advice are welcome.
Blueteeth