150w inverter

[Arthur Alchin]

i have a 12 to 240v 150w inverter (DSE model) for use in the field to drive the macbook. The inverter runs off a near new fully charger deep cycle 12v 70aH battery

I have put a mulltimeter across the inverter output and can only raise 180-190 volts which i don't think is great. Had to replace the battery of the Mac last week (under warranty) after 1 session of use on the inverter, the Mac is only 7 weeks old.

Question: could the low voltage be responsible for the death of the battery??

[Karls48]

Voltage output of cheap invertors is a modified square wave. Multimeter cannot display accurate voltage when reading modified square wave as it is calibrated for sine wave. I have been using infrequently small invertor to run Toshiba and IBM notebooks without problems. I know nothing about MACs but if it can accept DC input you are better off by using DC/DC converter. It got more stable output, less noise and uses less power from your battery.

[rogerg]

I would be surprised if it's to blame because you would be running your mac through a transformer from the inverter presumably, and that transformer taking it down to 18v or something. I'd think if there was any problem with the voltage the mac power supply, that transformer, would cut out. I see the transformer you have plugged in to the inverter as being a bit of a "buffer" so to speak. If the mac transformer/power supply died, then I would be suspecting the inverter.

I have used a DC/DC inverter most of my time and would recommend that over a 240v DC/AC inverter. But I have recently been forced to switch to using a DC/AC 240v inverter because my Dell XPS has such a propitiatory plug style and voltage. But the inverter wastes 500mA just running its self :(