Originally Posted By: jsb025
I've done some digging on this topic and I haven't come up with much in the way of useful information. So I ask, must a battery be removed/disconnected from a modern car before charging/maintaining?
If it matters I use an SC-600A.
Old topic, but in general Schumacher doesn't recommend that their "chargers" be used for long term maintenance mode. They have a variety of maintainers, including some that used to be marketed for charging power equipment batteries and classic car batteries. I think the PS-1562A (1.5A) was supposed to be used on a battery that was near fully charged and would cut off if it didn't reach maintenance mode in maybe 12 hours. I had one and lent it to a coworker who borrowed my jump starter and kept on finding that the battery wasn't charged enough to start again. Really - when you're at that point it's best to have a real external battery charger fully charge the battery.
The manual says it's OK, but I would think that a a lower current (Schumacher has 0.75A/1.5A/2A) maintainer would be better for that purpose. There's a 0.75A one I've seen at Walmart for less than $10. It's basically a wall wart with cables and a clamp. I also had a couple of different 1.5A maintainers. The old one is heavy with a coil transformer and isn't microprocessor controlled. The newer one is really light (can't seem to find it though) and had a noticeable electronic buzz typical of a switch-mode power supply.
This is what the manual says:
Quote:
http://www.batterychargers.com/content/pdf/0099001462-R0.pdf
MAINTAINING A BATTERY
The SC-600A-CA and SC-1000A-CA maintain both 6 and 12 volt batteries, keeping them at full charge. They can charge and maintain both small and large batteries.
NOTE: The maintain mode technology allows you to safely charge and maintain a healthy battery for extended periods of time. However, problems with the battery, electrical problems in the vehicle, improper connections or other unanticipated conditions could cause excessive current draws. As such, occasionally monitoring your battery and the charging process is recommended.
I've got an SC-1200A-CA myself, and I'll typically use it on 3A mode if I'm not in a hurry. That one has a display that shows battery voltage when it's connected without charging, and then when it charges it alternately flashes "12" and a percentage charge state for the battery. It also says that the 3A maintain mode is OK. However, I try not to keep it on maintain mode.
