Computer Audio Asylum Music servers and other computer based digital audio technologies.

---

[ Follow Ups ] [ Post Followup ] Thread: [ Display  All  Email ] [ Computer Audio Asylum ]

---

[ Alert Moderator ]

---

NiMH battery packs on my microRendu streamer - pics

Posted by AbeCollins (A) on September 30, 2016 at 10:19:23

7.2VDC NiMH battery packs on my microRendu sound better than that over priced $50 iFi wall wart and right up there with my lab grade LPS. $30 and change for the 5Ah battery, about $60 for the larger 10Ah unit.

After verifying E-Stat's comment that the ESR for Li-Ion types is higher than NiMH I went with NiMH, and discovered some other advantages over Li-Ion.

NiMH batteries have a much flatter (nearly ideal) discharge curve. In other words, as the battery discharges and depletes, the voltage stays very constant. Li-Ion on the other hand tends to sag downward linearly over time.

But NiMH have some disadvantages. NiMH energy density by weight is almost half that of Li-Ion. In other words, NiMH weighs a lot more for a given amount of energy. NiMH also have a higher self-discharge rate of about 20-30% per month vs 5-10% for Li-Ion. None of these are an issue in my application.

Of course if you're inclined to spend the big bucks there's the UltraCap LPS-1 for $400.

$30 NiMH 5Ah Battery gets about 16 hours of run time before recharge

$60 NiMH 10Ah Battery gets about 32 hours of run time before recharge

10Ah and 5Ah 7.2VDC NiMH batteries side-by-side

The microRendu with my DAC attached draws about 250mA so do the math on run time. Rather than depleting the batteries completely I derated the run time figures above by about 20%.

[Edit Oct 1 2016]:
My micrRendu with DAC attached presents a 250mA steady load on the 10Ah 7.2v NiMH battery pack. The battery measures 8.2v fully charged, 7.6v after 18 hours, 7v after 36 hours. Remove it from the system and place it on the charger. A slow charge takes ~12-hours, a fast charge ~6-hours. I prefer the 1-Amp slow charge vs the 2-Amp fast charge as the fast charge makes the battery quite warm and I charge the battery unattended.

Under my normal listening conditions of maybe 2-3 hours per day, the 10Ah battery should last about 2 weeks before a recharge.

I already own the charger from a previous battery setup for a phono preamp. The charger is about $30.

• Where to buy battery related goodies   (Open in New Window)

Edits: 10/01/16 10/02/16

This post is made possible by the generous support of people like you and our sponsors:

Parts Connexion

---

[ Top of Page ] [ Contact Us ] [ Support/Wish List ] [ Copyright © 2024, Audio Asylum, all rights reserved ]

---

[ General ] [ Speakers ] [ Tubes ] [ Vinyl ] [ Digital ] [ Hi-Rez ] [ Video Asylum ] [ Cables ] [ Tweaks/DIY ] [ Music ] [ Films ]

---