RTC current

NETMF & Gadgeteer
1

I have this issue in the field that the RTC battery is dead in many ChipX boards.

I recently measured it and see that is is using 64uA.
So a CR2032 will drain in 5 months

Is correct.
Is there a better solution.
Does any body else have the same issue

2

I have about 20 Chipworkx boards in the field, some now more than one year. I did not notice the battery’s to be dead, but I have to admit that I did not really checked also.

I will do some testing later tonight and let you know what I measure.

3

Thanks Nick

If the board is on, then things are ok.
Because there is no battery drain. In fact the battery is being charged I guess.
because there is a 1K5 to VBAT. The current flow is in reverse -1uA.

But if the units are in storage. Before the customer uses it. Then it is all dead if they leave it in storage for 5 months.

4

I measured the same thing here.

I guess I never noticed it before, because I don’t put the battery on the board until I actually use it. Until that time, I leave it in it’s packaging and add it to the box in which I store my finished product.

It seems a bit strange to me that the battery would be charged a bit, since this type of battery is not rechargeble. Won’t it be damaged when there is current flowing to it? I don’t considder myself an expert on analog electronics, maybe someone else who has expertise in this?