While I appreciate all of your expertise and input I am now heading towards the dreaded glassy eyed condition...I'll admit my ignorance right up front...I've been following the various backup power posts with the hope of finding just the right set up that would work for me at home however, I get glassy eyed with some of the technical jargon.
I understand the need to be very careful around electricity and to advise others to do the same when you are offering your opinions. But right now with the conversation between CapnLoki, Guest and Archangle I'm confused as to what is educated opinion and what is fact and whether to get bogged down in the off topic conversation.
In an attempt to steer the conversation back to my original post, let me start with:
The Duracell manual says:
1. "Once fully charged, the charging current automatically reduces to a maintenance charge mode, and the Duracell Powerpack Pro may be left permanently connected to the AC cord." "All rechargeable batteries gradually discharge when left standing, and you need to recharge them periodically to maintain maximum battery capacity. The charger within the Duracell Powerpack Pro is designed to regulate the charging process, ensuring that the battery is always fully charged but never overcharged..."
2. "Connecting to an external battery: You can extend battery operating times by connecting the Duracell Powerpack Pro to a larger external battery. For example an external 54Ah battery gives approximately 3 times the operating time of the Duracell Powerpack Pro internal 18 Ah." The manual goes on to describe connecting the powerpack using the jump-start cables: first making sure the jump-start power switch is off then connecting the red positive clamp to the positive (+) terminal and black negative clamp to the negative (-) terminal. Then turning the jump-start power switch on.
3. "As the DC power outlet is internally wired to the Duracell Powerpack Pro's battery, extended operation of a 12V DC appliance may result in excessive battery discharge. "The DC power outlet does not automatically switch off when the internal battery is discharged. Check the battery status periodically to prevent total battery discharge."
I hope that I can trust what Duracell tells me as these are the principals on which I based some of my design. I will leave the powerpack plugged in so that it is always fully charged and if I do need to use the powerpack, I will unplug the AC first, use the powerpack and then plug it back in to recharge once I'm done. When using the DC connection I will also periodically check the battery level of the powerpack to avoid a total battery discharge and will recharge it after each use. I am comfortable with handling the jumper cables and connecting to an external battery when and if the time comes. If 'the big one' happens and we are without power for a number of days I will follow #2 above making sure to protect the cables and terminals from inadvertent contact with each other and any other metal (read NO SCREWDRIVERS, CATS or BREAKFAST TRAYS ALLOWED ) and I will not have an open flame or flammable liquid in the area either. It actually helps to write this out and say it out loud so that these 'rules' are now part of the drill so thanks for that!
I think the big issues left on the table are how to charge the powerpack and the external battery in the case of an extended outage and this is where I get skittish with the statements made so far. I believe we have a consensus that I can recharge both batteries using my car; by using the DC outlet for the powerpack or by attaching the external battery to my car battery and then turning on the car and letting it run. Using a car may not be ideal depending on my fuel levels but that will work. I can always get a generator or a solar panel (yike$) but if I want to charge my powerpack using the jumper cables and car I am potentially risking damage to my home and/or the powerpack (or not, depending on the contributing sources). Have I boiled this down correctly?
I get that any path I choose comes with risks but I can't account for every possibility of failure so what I'm looking for is a relatively safe battery charging design that will bridge the gap in the case of an extended power outage (preferably without blowing my home up in the process)? I apologize if I'm being dense here but this topic is not my forte yet I still need to accomplish my task. Anyone else have any practical experience with this topic?
thanks,
d