The rechargeable Wildeye has a temperature limit that prevents it from recharging over 104°F (40°C), to protect the internal battery. Lithium Ion batteries should not be charged at temperatures over 104°F (40°C).
In sustained high temperature environments, for high power applications such as real-time weather stations or control systems, this can result in a Wildeye internal battery depleting to the point where the unit will go offline.
These problems can usually be overcome with a combination of the following recommendations:
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Position the solar panel to receive maximum sun energy early in the morning, when the temperature is cooler. Ie angle away from midday sun, toward morning sun
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Shade the logger from direct sunlight. Request a solar panel extension cable to allow mounting of the Wildeye away from the panel.
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Reduce the Wildeye connection frequency as much as possible
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Reduce the Wildeye attached sensor logging frequencies as much as possible
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Increase the size of the solar panel, to make more use of morning sun
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Swap to a long-life external battery instead of solar, for the hottest months. This will allow the logger to recharge from the external battery overnight. See Wildeye Large Rechargeable Battery Pack (ACC-BP-LIION-15V88WH)
Once adjustments have been made, note that the Wildeye may take some time to recover from going into its hibernation mode (hours of direct sunlight - up to a full day).
If these adjustments still do not allow enough recharge, then consider upgrading the installation to an external SLA battery recharge option. Contact Wildeye support for more details. The external SLA will hold enough charge to allow the Wildeye to recharge during the cooler night hours.
Details
The Wildeye has an internal temperature sensor. When the sun hits the logger and heats it the temperature sensor will detect this.
Resellers can access the rechargeable battery temperature, internal voltage and external voltage data from the Reseller administration login for an individual logger.
The temperature sensor has a 1% accuracy. The temperature cut-off circuit has about a ±3°C variance at 40°C. It also has a 5°C hysteresis, meaning after switching off it will only switch on again after the temperature has improved by 5°C.
This will explain why a Wildeye may charge in the morning while approaching 40°C, but not in the evening once the temperature drops below 40°C.