Rechargeable power boost 500 and solar power

General project help for Adafruit customers

Moderators: adafruit_support_bill, adafruit

Please be positive and constructive with your questions and comments.
Locked
User avatar
noanalyst
 
Posts: 139
Joined: Thu Sep 04, 2014 11:17 pm

Rechargeable power boost 500 and solar power

Post by noanalyst »

I just purchased the POWERBOOST 500 CHARGER - RECHARGEABLE 5V LIPO USB BOOST and I want to recharge it with a 5volt solar panel rather than the micro usb. Can I just connect my solar panel to where the micro usb is? If not, is there any workaround whereby I can get it to work with a solar panel?

User avatar
adafruit_support_bill
 
Posts: 88093
Joined: Sat Feb 07, 2009 10:11 am

Re: Rechargeable power boost 500 and solar power

Post by adafruit_support_bill »

It will probably OK work under ideal sun conditions. But the marginal cases are a problem with solar. That is where you are better off with a charger designed for solar use.
https://learn.adafruit.com/usb-dc-and-s ... sign-notes

User avatar
noanalyst
 
Posts: 139
Joined: Thu Sep 04, 2014 11:17 pm

Re: Rechargeable power boost 500 and solar power

Post by noanalyst »

But for the USB, DC & Solar Lipoly Charger, if I am out in the sun and suddenly a cloud comes through so there is no solar charging, what happens to my load. Will it automatically draw power from the battery....like a UPS. Then what happens when the sun reappears.

User avatar
adafruit_support_bill
 
Posts: 88093
Joined: Sat Feb 07, 2009 10:11 am

Re: Rechargeable power boost 500 and solar power

Post by adafruit_support_bill »

It will do that. Just not very efficiently. A standard charger will stop charging as soon as the panel output starts to drop. The solar charger will continue to charge at a slower rate.

User avatar
noanalyst
 
Posts: 139
Joined: Thu Sep 04, 2014 11:17 pm

Re: Rechargeable power boost 500 and solar power

Post by noanalyst »

But how about when the sun reappears. Will the charger resume charging at full capacity? Will my load (e.g my iPhone charging) be affected in anyway during the time the sun disappears and then reappears?

User avatar
adafruit_support_bill
 
Posts: 88093
Joined: Sat Feb 07, 2009 10:11 am

Re: Rechargeable power boost 500 and solar power

Post by adafruit_support_bill »

It will start up again when the sun re-appears. But since the charging cycle was interrupted, it will probably have to go through the pre-conditioning 'trickle-charge' stage.

User avatar
noanalyst
 
Posts: 139
Joined: Thu Sep 04, 2014 11:17 pm

Re: Rechargeable power boost 500 and solar power

Post by noanalyst »

Sorry what do you mean "pre-conditioning 'trickle-charge' stage". What is that? How long does it last?

User avatar
adafruit_support_bill
 
Posts: 88093
Joined: Sat Feb 07, 2009 10:11 am

Re: Rechargeable power boost 500 and solar power

Post by adafruit_support_bill »

You don't charge LiPo batteries by simply pumping current into them. That is dangerous. The charge controller will test the battery voltage and start 'trickle' charging it at a slow rate. Once it determines that the battery is fit to be charged, it will start increasing the charge rate. The time that takes depends on the condition of the battery.

User avatar
noanalyst
 
Posts: 139
Joined: Thu Sep 04, 2014 11:17 pm

Re: Rechargeable power boost 500 and solar power

Post by noanalyst »

Can you tell me what the voltage and max wattage of the load output of the charger?

User avatar
adafruit_support_bill
 
Posts: 88093
Joined: Sat Feb 07, 2009 10:11 am

Re: Rechargeable power boost 500 and solar power

Post by adafruit_support_bill »

For the solar charger, the output voltage of the load-sharing circuit will be the higher of: The supply voltage or the battery voltage. In other words, when there is plenty of sun, the excess solar power is passed straight through to the load (up to 6v). When solar output drops, the circuit switches to the battery (3.7v).

The charger can supply up to 6v @ 1.8A (10 Watts) to the load - assuming you have a panel that size..
http://www.adafruit.com/datasheets/MCP73871.pdf

Locked
Please be positive and constructive with your questions and comments.

Return to “General Project help”