Choosing a Battery

[cleve]

Update,
Thought about the possible need to quickly grab my CPAP machine and head for the cellar in the event of severe weather here in Oklahoma so I bought the box which will have room for the CPAP machine and the accessories too maybe. Thinking I made the right choice.

[CapnLoki]

is your opinion on a bit of overkill related to the size of the box or the features? I do think the box is overkill but would sacrifice size for what I think are very complete features. Esp not having to open the box to check voltage.
Thanks, Cleve

The size is one thing, the other is the cost. The nice things the box provides are the socket, which is a $10 item, and the "state of charge" and I'd prefer to use a real volt meter. Actually, I have an in-line volt and amp-meter that totals the usage. But as I've said, I have no problem with a fancier box. My goal is often to recommend the best "bang for the buck" solution; there's nothing wrong with spending a few bucks on a fancy package.

[Guest 3]

Update,
Thought about the possible need to quickly grab my CPAP machine and head for the cellar in the event of severe weather here in Oklahoma so I bought the box which will have room for the CPAP machine and the accessories too maybe. Thinking I made the right choice.

In that case you prob have no idea how long battery power will be needed? Would a 100A battery be a wiser choice? Just leave it in the basement on trickle with a spare cpap if you have one.

[cleve]

Not that kind of a cellar. It's out in the yard and no power inside. Anyway I would not want to lug a 100a battery plus the other vital gear that I'd want to take along.
Thanks Cleve

[kkb]

Ok....I am so sorry but I have read and re-read trying to figure out exactly what I need. I was one that was without power due to Irma and unfortunately had to sleep (for lack of a better term...not much "sleep" to be had). I want to be prepared in the event of another power failure. Can someone tell me in plain English what I need as far as a battery backup?

[CapnLoki]

Ok....I am so sorry but I have read and re-read trying to figure out exactly what I need. I was one that was without power due to Irma and unfortunately had to sleep (for lack of a better term...not much "sleep" to be had). I want to be prepared in the event of another power failure. Can someone tell me in plain English what I need as far as a battery backup?

There are several paths. First of all, since you have a ResMed you should get the DC/DC converter, about $85, that allows you to run directly from a 12 volt battery. The battery I like for home backup use is a 35 Amp hour battery that weighs 24 pounds. This should run your pump for 4-5 nights; larger batteries could go longer. You need a battery charger plus a few extra cables. This is all described earlier in this thread, in a post titled "My Battery Backup Setup."

There are other approaches, such as a jump starter, but these usually come with a smaller battery that would only run for several nights. Or a Uninterruptible Power Supply, but these have even smaller batteries.

So track down the setup post, and see if that makes sense. Hopefully in the next week or so I'll post pictures of my setup.

[kkb]

Ok....I am so sorry but I have read and re-read trying to figure out exactly what I need. I was one that was without power due to Irma and unfortunately had to sleep (for lack of a better term...not much "sleep" to be had). I want to be prepared in the event of another power failure. Can someone tell me in plain English what I need as far as a battery backup?

There are several paths. First of all, since you have a ResMed you should get the DC/DC converter, about $85, that allows you to run directly from a 12 volt battery. The battery I like for home backup use is a 35 Amp hour battery that weighs 24 pounds. This should run your pump for 4-5 nights; larger batteries could go longer. You need a battery charger plus a few extra cables. This is all described earlier in this thread, in a post titled "My Battery Backup Setup."

There are other approaches, such as a jump starter, but these usually come with a smaller battery that would only run for several nights. Or a Uninterruptible Power Supply, but these have even smaller batteries.

So track down the setup post, and see if that makes sense. Hopefully in the next week or so I'll post pictures of my setup.

Thank you Capn Loki....I honestly consider myself a smart person but all of this was like Greek to me. I will see if I can track down the setup post.

[cleve]

Here are links to my setup with the carrying case that I can easily take along camping, etc. Weight is probably short of 32 lbs all included.

DC adapter
https://tinyurl.com/yboxej38

35 amp AGM battery
https://tinyurl.com/ybvsgps4

AGM battery charger
https://tinyurl.com/y7mld7bu

Battery Case
https://tinyurl.com/y76juvvj

[kkb]

Here are links to my setup with the carrying case that I can easily take along camping, etc. Weight is probably short of 32 lbs all included.

DC adapter
https://tinyurl.com/yboxej38

35 amp AGM battery
https://tinyurl.com/ybvsgps4

AGM battery charger
https://tinyurl.com/y7mld7bu

Battery Case
https://tinyurl.com/y76juvvj

Thank you Cleve...this is helpful!

[davecpap]

This older thread seems to have a pretty nice parts list/instructions for building a safe battery backup solution.

viewtopic.php?f=1&t=89123

Anyone know of any improvements or similar (newer) instructions? This thread has smilier info, but the above thread is very explicit about what to buy and how to put it together.

[cleve]

The post I made above features a battery box with carrying handle and a button on the exterior you press to check the charge in the battery. I think that's an option worth the added cost. Total for the entire setup was >$260.

[davecpap]

The post I made above features a battery box with carrying handle and a button on the exterior you press to check the charge in the battery. I think that's an option worth the added cost. Total for the entire setup was >$260.

Is there a way to secure U1 size battery inside the Minn Kota power center intended for Group 24/27 batteries? The Minn Kota is attractive, but not sure I want to carry a 50lbs battery. I see you specified a smaller U1 battery on your shipping list.

Thanks!

[cleve]

I chose the larger box b/c it has handle and enough room for a charger and the AC adaptor in case I have to make a hurried dash to the storm cellar outside. I also like the two 12V auto DC ports on the outside. I have a 12V to USB adapter I can plug in to one to charge my cell phone.

[ColinP]

This older thread seems to have a pretty nice parts list/instructions for building a safe battery backup solution.

viewtopic.php?f=1&t=89123

Anyone know of any improvements or similar (newer) instructions? This thread has smilier info, but the above thread is very explicit about what to buy and how to put it together.

That thread is a great find, and covers it very well.

[CapnLoki]

This older thread seems to have a pretty nice parts list/instructions for building a safe battery backup solution.

viewtopic.php?f=1&t=89123

Anyone know of any improvements or similar (newer) instructions? This thread has smilier info, but the above thread is very explicit about what to buy and how to put it together.

John's thread was the inspiration for much of my work - John's concepts and writeup are wonderful and I encourage those who are interested to study his design.

However ...

I started looking into smaller, simpler setups because a number of people posted that this is too complicated and anything that required drilling holes and soldering wires was beyond their capabilities. I realized that as nice as John's setup was, much of it was unnecessary. In fact, all that is really needed is a battery, two bolts to attach a cable, a BatteryTender which comes with most of the cables, a "cigarette socket" (which is a standard BatteryTender accessory), a box, and the appropriate DC adapter for the pump. The only technical part of the assembly is bolting on the color-coded connectors. This setup is within the abilities of a much wider group of users.

I have nothing against John's design - in fact I've implemented all of it, and much more, on my boat - six batteries, five solar panels, two alternators plus a genset, 4 inverters, Amp-hour meters and volt meters, and on and on... All nice, but not necessary to power one device.

I would point out that there are those on the other side of this issue, that feel that "all-in-one" jumpstarters or UPS's are a better solution. They have a place, but have various limitations. I decided to focus on choosing the right size and type of battery since that would serve a lot of users. Anyone desiring a fancier solution would still have to start with a battery and a charger - I didn't want to discourage folks by adding too much "fluff."