Re: Max input voltage for RNDU2000

firerain · ‎2016-09-23

Hi there!

I'm trying to find some info about max input voltage for RNDU2000 (and not only this one, I assume).

I'd like to connect it with a buffer power supply which outputs 13.8V at default. Of course, there is an option to reduce it to 12V but then the battery will be charged with 12V, which isn't the best option. I'd like to stick to 13.8V but I don't want to risk damaging my ReadyNAS.

Any experience in this matter?

c3po · ‎2016-09-24

Design spec is 12V +/- 5%. On-board DC-DC circuits typically work within +/- 20% range.

BUT: 12V to hard drive is unregulated(except very low voltage drop switch), please check your hard drive 12V rating (typically +/- 10%). So 13.8V is a little over hard drive 12V rating.

View solution in original post

JennC · ‎2016-09-24

Hello firerain,

It only says DC 12.0V, 5A but we're checking with the engineers.

Welcome to the community!

Regards,

firerain · ‎2016-09-24

@JennC wrote:
It only says DC 12.0V, 5A but we're checking with the engineers.

That would be just awesome to get info from the source!

The voltage reduction circuit isn't very expensive but still I'd rather not to spend more money on this project and whats more, I'd need to make additional space in the casing.

Thanks for the welcome

c3po · ‎2016-09-24

Design spec is 12V +/- 5%. On-board DC-DC circuits typically work within +/- 20% range.

BUT: 12V to hard drive is unregulated(except very low voltage drop switch), please check your hard drive 12V rating (typically +/- 10%). So 13.8V is a little over hard drive 12V rating.

firerain · ‎2016-09-24

Much obliged!
I didn't think of that HDD power supply may not be regulated.
You are right, my WD30EFRX tolerance is 10%. I could just set the output voltage to 13V but I don't want to risk frying both of my HDD's due to some power noise.
I will think it over but I assume that I will end up buying that voltage reduction circuit. It will make things a bit more complicated (like having to use 2x 9Ah batteries instead of one) but it's a safe option.
Thanks a lot both of you!