solar cells to lead acid battery charger with pic single chip computer

[walle62]

Dear Friends

I must design for my company a solar cells (17 V nominal) to lead acid
gel battery (12V nominal, 14.6V charge final voltage) charger.

I want to use a pic single chip computer with A/D and D/A-converters
for regualting between solar cells and battery/load line with two
cool-mosfets (these are the same as a logic level mosfets). the unit
should also prevent against solar back current in the night,
overcharge, undercharge and load over current.

I also must implement a battery charge measurement (in Ah), i want to
do this with the pic (measuring the battery charge/discharge current
and integrating this current up/down respectively).

The surge load current is 20A or 40A, nominal load current is about 5A
or 10A.

Do you have ideas, critics, questions or suggestions? I'm glad about
every answer from you. I also would like to help somebody with similar
questions. For a very helpful idea or a good design we would pay, if
you want. Thank you very much!

Walter Nussbaum, dipl. Electronics Engineer ETH, Megasol Inc.,
Höhenring 17, 8052 Zürich

mail: [email protected]

phone: +41 43 268 90 32 mobile: +41 79 297 62 78

 

[martin griffith]

Dear Friends

I must design for my company a solar cells (17 V nominal) to lead acid
gel battery (12V nominal, 14.6V charge final voltage) charger.

I want to use a pic single chip computer with A/D and D/A-converters
for regualting between solar cells and battery/load line with two
cool-mosfets (these are the same as a logic level mosfets). the unit
should also prevent against solar back current in the night,
overcharge, undercharge and load over current.

I also must implement a battery charge measurement (in Ah), i want to
do this with the pic (measuring the battery charge/discharge current
and integrating this current up/down respectively).

The surge load current is 20A or 40A, nominal load current is about 5A
or 10A.

Do you have ideas, critics, questions or suggestions? I'm glad about
every answer from you. I also would like to help somebody with similar
questions. For a very helpful idea or a good design we would pay, if
you want. Thank you very much!

Walter Nussbaum, dipl. Electronics Engineer ETH, Megasol Inc.,
Höhenring 17, 8052 Zürich

mail: [email protected]

phone: +41 43 268 90 32 mobile: +41 79 297 62 78

check the archives here, Larwe posted a simalar question recently


From: [email protected]
Newsgroups: sci.electronics.design
Subject: Request comments on simple solar charger
Date: 23 Jul 2005 16:31:12 -0700
Organization: http://groups.google.com
Lines: 24
Message-ID: <[email protected]>


martin

 

[walle62]

dear martin

thank you very much for your answer.

i read in the archive, especially this article from jul 23 2005. it was
very interesting and i learned something new again.

yours sincerely

walter nussbaum

mail: [email protected]

 

[Iwo Mergler]

Dear Friends

I must design for my company a solar cells (17 V nominal) to lead acid
gel battery (12V nominal, 14.6V charge final voltage) charger.

I want to use a pic single chip computer with A/D and D/A-converters
for regualting between solar cells and battery/load line with two
cool-mosfets (these are the same as a logic level mosfets). the unit
should also prevent against solar back current in the night,
overcharge, undercharge and load over current.

I also must implement a battery charge measurement (in Ah), i want to
do this with the pic (measuring the battery charge/discharge current
and integrating this current up/down respectively).

The surge load current is 20A or 40A, nominal load current is about 5A
or 10A.

Do you have ideas, critics, questions or suggestions? I'm glad about
every answer from you. I also would like to help somebody with similar
questions. For a very helpful idea or a good design we would pay, if
you want. Thank you very much!

Walter Nussbaum, dipl. Electronics Engineer ETH, Megasol Inc.,
Höhenring 17, 8052 Zürich

mail: [email protected]

phone: +41 43 268 90 32 mobile: +41 79 297 62 78

You may want to consider optimising for maximum power
from the solar cells. Basically, you build a switch-mode
battery charger which regulates it's power troughput
to maximise I*V on the solar cell side.

That would allow you to extract maximum power under
a wide range of conditions with less dependency of
full sunlight.

Kind regards,

Iwo

 

[walle62]

Hi Iwo

Thank you for your answer. It's a good idea to use MPT, although it
makes the SW a bit complex. But it's worth while to think about it.

Kind regards

Walti

 

[walle62]

Dear Chris

You're absolutely right, but my chief want to design a own one..

Thank you very much for your suggestions.

walti

 

[Fred Bloggs]

Have you read homepower magazine?
http://www.homepower.com/

Largely crap for homesteaders...very little technical content.

 

[Chris Jones]

Dear Friends

I must design for my company a solar cells (17 V nominal) to lead acid
gel battery (12V nominal, 14.6V charge final voltage) charger.

[snip]

Depending on cost and quantity, you might be able to buy this more cheaply
than designing it. Have you read homepower magazine?
http://www.homepower.com/

There are lots of advertisements in there for charge controllers etc.

Chris