DSSR20 with Diversion: Diversion on, when Bat Low Temperature Disconnect active?

[Peter]

I understand, the diversion is active, when the battery is full and doesnt allow charging. Is it also on, when the SBMS doesnt allow charging due to low temperature?

Thx

[A. J. Tarnas]

that's funny! if the battery ever gets to low temp during daylight, the panels could dump some heat nearby. rare case but possibly useful.

[Dacian Todea]

Peter,

Yes diversion will be ON if battery is not charging no matter the reason battery is not charging including low battery temperature.

But you need to understand that if battery is not in an isolated and heated box then if battery drops below freezing it will take hours (if ever) for the battery to get back to operation temperature and by that time sun may be gone.

Battery has thermal mass so you can not just heat the external of the case and start charging as internally the battery may still be below freezing and it will still get damaged. And if there is no insulated box and ambient temperature is low you will never be able to heat the battery even if you use all PV energy for that hundreds of Watt as heat loss will be higher than you can provide.

So the only proper solution is a well insulated battery box and a very small 10 to 15W battery heater control by a digital thermostat set to maintain above +10C (50F) at all times.