A friend of mine does recording but the battery charger for his laptop creates a lot of noise. Problem is his laptop doesn't run long enough on the regular battery (or even a bigger one) to do anything he needs to do.
I was thinking of fixing this going battery operated. Just buy a huge SLA battery, put it in a box with a charger and a selector switch... but as I understand batteries voltage will decrease some if it starts to lose too much charge. However I've seen a few PSU's for audio equipment that have a constant voltage discharge circuit. I was wondering if anyone sells one or something?
Aside from that, maybe a linear power supply that makes less noise would work. Also could build a power conditioner for him but... the $ for that is bit more than the first two options!
