Hello, I am working on a project that uses a 48 VDC battery pack as the primary power source. The battery is connected to a DC-DC converter that provides 12 VDC to our system. The 12 VDC bus powers: A mini PC Communication peripherals Various electronic components The total system load is approximately 30 W to 45 W under normal operation. We are looking for a power backup or hold-up solution that will allow the system to remain powered while the 48 V battery is removed and replaced for recharging. During the battery swap, the system should continue operating without interruption for approximately 30 seconds to 2 minutes. We are interested in recommendations for: Supercapacitor backup modules DC UPS solutions Hold-up modules Other suitable products that can maintain a regulated 12 VDC output during the battery exchange process Key requirements: Input source: 48 VDC battery Output voltage: 12 VDC Load: 30-45 W continuous Backup duration: 30 seconds to 2 minutes No interruption to the mini PC during battery replacement Industrial-grade solution preferred Could you please recommend suitable products available through Digikey, along with any application notes or reference designs that may be applicable? Thank you for your assistance. Best regards,
Hello m.salihovic,
Welcome to the DigiKey TechForum.
I searched the DigiKey site for some Ultra Capacitor modules for a backup.
Click Here for the 12V and 48V output options.
Please check the datasheets to verify compatibility to your application.
Hopefully if one of the engineers have another solution, they can add to this post.
Thank you ! I will take a look.
What’s the part number of the converter? If its input range extends substantially downward from the 48V mark, simply putting a supercap of appropriate specification in parallel with the battery input (plus some minor accommodations…) might be a very straightforward approach. The larger among these may be sufficient to get a person there, depending on the details.
hi , this is the
| DigiKey Part Number | 1866-5065-ND |
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So assuming a capacitor bank across the DC input and cycling between 36V (end-of-discharge for a 48V lithium battery) and 20V (converter input minimum plus a margin) it would appear that a person would be needing about 13 Farads to cover 45W for two minutes, factoring in a bit of loss. The basic idea might look like the below, where the resistance limits charge current on re-connection, and is bypassed by the diode during discharge. Basic problem with this is the resistance burns off a lot of power during the charge cycle and slows things down, so a more involved solution involving a switch mode solution would be needed. But if one’s not interested in component-level design, the approach is probably out.
If one’s more into building with blocks that are DIN mountable, the DUSH960 units from TDK look rather interesting and might be exactly what you’re after; DC in & out with backup storage that’s flexible in format. Note that the manual with more information is further down the product page under “Documents and Media.”