Yup; you're right. But even 0.98 should be too high unless that is an acceptable value for newer vehicles with more computers. Be aware too that there are now some computers that draw high current until they go to "sleep" mode.
These numbers are from a Chrysler training session. Unfortunately, whatever stupidity GM develops to add complexity to their cars, Ford and Chrysler seem to copy, but there's no denying you can't have an excessive drain on the battery and expect it to start the engine. According to Chrysler, their accepted standard was a drain of.035 amps, (35 milliamps), as normal and that would guarantee the engine would start after sitting for three weeks. I found between 10 and 20 milliamps on the few cars I checked.
It is common for the Body Computer, starting on a few models around the late 1990s, to draw three amps for 20 minutes until it went to sleep mode. Genius, huh? Not only is that misleading, it also makes troubleshooting for a drain very difficult. If you use a digital multimeter in series with a battery cable to measure current, you will pop its internal fuse unless you put it on the 10 amp scale. Later, when the draw drops, you have to switch to a lower scale for more accuracy. Switching involves moving a test lead to a different jack on the meter or switching the range switch. Either action involves momentarily opening the circuit which sends the computer back to "wake" mode and it will draw three amps for another 20 minutes. The secret is to set up the ammeter on the lower scale with the probes attached to the battery post and cable while keeping them connected with a jumper wire. That will prevent blowing the internal fuse. After 20 minutes, the jumper can be removed so current can only go through the meter which is already on the lower scale.
Sunday, June 20th, 2010 AT 1:58 PM