Since it’s been a while since we’ve discussed the side of my wheelchair’s electrical system that supplies power to a range of devices, including the mobile laptop, a quick review would be helpful.
Yes, your typical power wheelchair is strictly 24 volts; however, my wheelchairs are never typical. Tied into the mainline from the two Group 24 AGM deep-cycle batteries is a commercial 18-36 to 12-volt converter that’s mounted on the door of a Hoffman box behind the seat. The converter is rated for 80 amps peak. A line goes from that converter into the Hoffman to a pair of terminal strips, where power is then distributed mainly to a variety of small after-market and personal electronics of insignificant amperage. However, there are two notable exceptions, an audio amplifier that’s stopped down to about 40 watts (this is how I can talk, provide kick-ass audio to groups, have wonderful gaming audio, etcetera, etcetera), and a line fused for 20 amps that runs up to the front of the chair to a block of three “vehicle accessory connections” (formerly known as “cigarette lighter outlets”). This is where your adapters get their power.
So you can readily see why we need to stick with the vehicle accessory connectors. I don’t personally like them either, but that’s because they’re vulnerable to the weather. The automotive industry rates them as adequate for up to 20 amps, and they’re a de facto standard. Enough other small detritus like smartphones occasionally need to suckle juice to require that connection block be there for accessibility reasons so we might as well continue using it. Besides, to be honest, the terminal strips are full, and I no longer have ready access to people capable of running another dedicated line back there even if there was room.
The good news is that Dell has finally figured out how to get enough computational horsepower out of 180 watts so no further power increases should be necessary. Oh, and, if you were wondering, all Dell laptops use the same input connectors, only the amperages differ. That’s a big reason why I stick with Dell.
From: Darrel Pinkston [mailto:firstname.lastname@example.org]
Sent: Wednesday, March 25, 2015 9:35 AM
To: Scott Royall
Subject: Re: 180?
We’ve done 180 before, but it must be direct wired or use connectors capable of 15 to 20 amps. At 24 volts which I think I remember that you use 10 to 15 amps.
So next we’d need to look into the plug for that new computer.
On Mar 24, 2015, at 9:13 PM, "Scott Royall" <royall> wrote:
Straightforward question: Can we manage 180 watts in my installation? I know, you’re rolling your eyes, but is it doable? I ask because I finally have a laptop that’s capable of doing everything I can ask of it. The only hitch is, it does occasionally need more than the 150 watts we presently offer. Its AC supply is rated for 180, and I think you once said we might be able to reach 200 on peaks.