Dear Core Electronics,
I would appreciate your assistance in selecting suitable components for a small solar light project. I spoke to Clinton yesterday afternoon who suggested I post my enquiry on your forum.
Background: I recently purchased a Deelat “Solar PIR and Security LED Light” system that includes motion sensor electronics and remote control only to find out that it had no manual operating mode which is all that I really need (a simple On/Off operation using an external light switch). I would like to change this to simple On/Off operation.
The Existing System details are: (see also attached photos)
Solar Panel: 6V, 5W
LED Panel: 44 LED, 1,000 Lumen, 15W, 3.7V
Battery: 3x individual 18650 cylinders (pink – brand unknown), 3.7V, 8,000mAh (per Deelat spec sheet), soldered onto a single circuit board which includes the solar charger and daylight and motion sensor electronics.
LED Enclosure Internal Dimensions: 180mmL x 50mmW x 30mmD
The metallic LED enclosure and intensity of the LEDs are great and I plan to re-use them along with the existing solar panel (both with flying leads). However, I plan to replace all existing batteries and electronics with new ones (plus an external on/off switch – not part of this enquiry). This means purchasing new batteries (capacity around 8,000mAh) and a compatible solar charger. This is the subject of this enquiry.
On your website I found the following that might possibly do the job, and I would like your advice regarding suitability, fire safety (Li batteries), availability, cost and delivery of all required components, as well as any other recommendations or solutions you can suggest:
A. 2 x CE04380 LiPo batteries (3.7V 4,400mAh), protected – connected in parallel
B. 1x CE04381 Li Po battery Pack (3.7V 6,000mAh), protected – connected in parallel; retired product?
C. Any other suggestion from you
Solar Charger Options
A. 1x AF-390 USB / DC / Solar Lithium Ion/Polymer charger v2
B. Any other suggestion from you
Additional points which need to be addressed are:
Confirm that any proposed batteries have min V, max V and max I protection as these chargers do not.
Highlight any charge/discharge issues with connecting identical batteries or battery packs in parallel (in case of increasing difference between individual battery conditions though initially “identical”).
What is the max charge current possible with the final proposed charger, and any special requirements for achieving this, e.g. the AF-390 has a 900mA option by soldering a 2K ohm resistor over the existing 2K resistor across the PROG pads (per the Adafruit manual). I am hoping to achieve something close to the max possible from the solar panel, around 800mA.
The new batteries and charger PCB will be placed inside the existing fully enclosed metal casing behind the LED panel. Please advise whether a hi temperature cut-out thermistor should be installed; the AF-390 charger has this option including thermistor (10K Precision Epoxy Thermistor - 3950 NTC, Product Id: 372).
What restraint options are available to protect the batteries from moving around inside the enclosure during installation.
What connectors are required to attach the solar panel flying leads to the charger, e.g. AF-369 (Male DC Power Adapter - 2.1mm Plug To Screw Terminal Block).
What connectors are required to attach the LED panel and series connected external On/Off switch (SPDT dry contact, flying leads) to the charger, e.g. PH plug or other spec.
What mounting supports are available to avoid the charger PCB contacting any metal surface inside the enclosure, e.g. Adafruit AF-1116 “Board Edge Mounting Kit - Pack of 4” or other, also to stop it moving around.
What options exist for adding remote status LEDs that can be mounted on the enclosure, as the charger PCB will be inside the enclosure, the charging status LEDs will not be visible from the outside. The AF-390 charger has this option.
Your early advice would be very much appreciated. Let me know if any you require any further information. Thank you.