Building a power pack. Need a battery recommendation. T

[Reisender]

Hi folks. I’m building a portable power pack. I’m looking for recommendations on a 40 to 60 amp hour battery. Something around the size of a group 24 ish sized battery or smaller. Part of the project is a 500 watt sine wave inverter. It will be moved from time to time so I would consider a Lithium (probably lifepo4) although an AGM would probably be fine. (Good exercise). Indoor use. Probably using a group 27 or 31 box as the project box. I would appreciate any suggestions on the battery. I did this years ago with a blue top battery and it’s still working well. But things have changed a lot in the battery world, especially with lithium and AGM and I know there are people here who are more current than I am.

I should probably get suggestions on a small charger as well in the case of lithium. In the last one I built I used a small 3.5 amp NOCO charger and mounted it right in the box. Any suggestions are welcome on any newer chargers. I’m open to anything.

Thanks all. Happy New Year.

[Reisender]

time2roll wrote:

Reisender wrote:
It actually started the fridge but didn't like it...which is fine as we won't use it for that.

Consider heavier copper on the 12v connection to improve surge performance. #6 wire should be plenty, keep it short and neat.

Yah probably. But the fridge is the job of the big one. The little power pack is for other uses. I was just curious what it would do.

[time2roll]

Reisender wrote:
It actually started the fridge but didn't like it...which is fine as we won't use it for that.

Consider heavier copper on the 12v connection to improve surge performance. #6 wire should be plenty, keep it short and neat.

[Reisender]

Well, we decided to make a couple mods to the unit I built a few years ago along with an improvement on our home UPS which I'll get to in a minute.

So here are a couple pics. I forgot to get one of the inside but suffice to say it contains an Optima Blue Top battery, various cables to connect to and be charged from a portable solar panel as well as a vehicle 12 volt power point and a 3.5 amp 12 volt NOCO charger. On the outside is a 400 watt sine wave inverter attached to the lid. There is an LED light and various power points as well as a meter for current and voltage. Good enough. Its heavy but the optima is apparently a 54 amp hour job so it did quite well as a portable power supply for our TV and charging requirements of things like phones etc. It actually started the fridge but didn't like it...which is fine as we won't use it for that.







But as I mentioned earlier, to solve the original problem, having additional backup capacity to run the fridge and TV in emergency situations we went with adding a second group 31 to our house emergency critical load backup. The only critical load is the fridge and a small TV to be able to watch the news in an extended power outage. We don't get a ton of outages here but weather or car accidents involving poles seems to have caused us more issues this year than in previous years and some have dragged on over a day...or more. So we wanted a little more capacity and a neater set up. We have used this system for a couple years but with half th capacity and not set up as neatly and out of the way. Anyway, we now call it our MYWANNABETESLAPOWERWALL 🙂 And here it is.

A 2 KW Samlex inverter with pass through transfer switch and 100 amp DC 4 stage battery charger. We limit it to 60 amps as it is plugged in to a standard 15 amp 120 volt outlet.

2 X Group 31 105 amp hour AGM batteries.

250 amp catastrophic fuse.

Breakered input and output power bars.

We ran separate lines to the fridge and entertainment centre so we wouldn't have to screw around in a power outage, and if we are away the fridge keeps running because of the auto transfer switch in the inverter/charger.

That and some Bricks, some wood and my wifes artistic lightning bolt mnaking skills...which I'm fairly certain give it more power. They're lightning bolts right. Not to mention it has Tesla in the name soooooo..... 🙂 (I'm a Tesla freak so...

I should note, during a power outage we do our cooking on a propane coleman stove, our lights come from a bunch of Ryobi LED lanterns and a bunch more Ryobi 18 volt 4 and 6 amp batteries and the house heat comes from a natural gas fireplace with a pilot light. Woohoo. Like camping at home. 🙂

Enjoy.

[Reisender]

TurnThePage wrote:
This has been on my todo list for a long time. I'm following. 🙂

I’ll keep you informed. Chasing down a few options. Deciding soon. I need a project.

[TurnThePage]

This has been on my todo list for a long time. I'm following. 🙂

[Reisender]

pianotuna wrote:

Reisender wrote:

pianotuna wrote:

Reisender wrote:
in the case of lithium.

The best bank for the buck for a 100 amp-hour (which are about the size of a group 27 jar) is $400 Cdn for Li. That include a BMS, of course.

https://ablithium.com/

As I'm certain you know I can't use Li.

Hi Don. Thanks for the link. I ended up at a KOYAMA battery site. Info is kind of sketchy. What brand of charger would you charge those with.

Hi,

With expensive batteries, I would follow the makers directions "to the letter" and if at all possible buy a charger from them that is "tweaked" to charge their product.

Thanks Don.

[pianotuna]

Reisender wrote:

pianotuna wrote:

Reisender wrote:
in the case of lithium.

The best bank for the buck for a 100 amp-hour (which are about the size of a group 27 jar) is $400 Cdn for Li. That include a BMS, of course.

https://ablithium.com/

As I'm certain you know I can't use Li.

Hi Don. Thanks for the link. I ended up at a KOYAMA battery site. Info is kind of sketchy. What brand of charger would you charge those with.

Hi,

With expensive batteries, I would follow the makers directions "to the letter" and if at all possible buy a charger from them that is "tweaked" to charge their product.

[Reisender]

wa8yxm wrote:
For the application I would suggest Lithium as they are lighter in weight and have some amazing "Features" Two companies who's products you should Check out are Battle Born and Bioenno power (Link on last below)

DO check with the company to insure they are what you want.

An aquantance of mine who does a podcast (Gordon West/Ham Nation) brags on Bioenno power... Claims they hold their output voltage fairly constant till they are all but dead. This is important for your use. also though I can not state for a fact I think you can run 'em rather far down (more so than a Lead Acid) so 50 amp hour of LI would be better than 75AH of Lead Acid (About a group 24)

bioennopower.com/

Thanks for the suggestion. I’ll check it out.

[wa8yxm]

For the application I would suggest Lithium as they are lighter in weight and have some amazing "Features" Two companies who's products you should Check out are Battle Born and Bioenno power (Link on last below)

DO check with the company to insure they are what you want.

An aquantance of mine who does a podcast (Gordon West/Ham Nation) brags on Bioenno power... Claims they hold their output voltage fairly constant till they are all but dead. This is important for your use. also though I can not state for a fact I think you can run 'em rather far down (more so than a Lead Acid) so 50 amp hour of LI would be better than 75AH of Lead Acid (About a group 24)

bioennopower.com/

[Reisender]

pianotuna wrote:

Reisender wrote:
in the case of lithium.

The best bank for the buck for a 100 amp-hour (which are about the size of a group 27 jar) is $400 Cdn for Li. That include a BMS, of course.

https://ablithium.com/

As I'm certain you know I can't use Li.

Hi Don. Thanks for the link. I ended up at a KOYAMA battery site. Info is kind of sketchy. What brand of charger would you charge those with.

[pianotuna]

Reisender wrote:
in the case of lithium.

The best bank for the buck for a 100 amp-hour (which are about the size of a group 27 jar) is $400 Cdn for Li. That include a BMS, of course.

https://ablithium.com/

As I'm certain you know I can't use Li.

[Reisender]

BFL13 wrote:
How long do you need to run how big of a load before you recharge the battery?

How much time do you have to recharge the battery before you need to use it again?

So the answer is, it varies. As low as 45 watts and as high as 225 watts. So does the duration it has to stay on. I think my blue top is around 38 amp hours. I would like to add a little extra capacity so 50 - 55 amp hours would work. I’m comfortable with AGM’s but I know Lithium have kind of become mainstream and they are soooo much lighter. And once we get into lithium all my past knowledge of chargers go’s out the window.

Heads up. I have the inverter picked out. 700 sine wave Gopower.

Thanks.

[BFL13]

How long do you need to run how big of a load before you recharge the battery?

How much time do you have to recharge the battery before you need to use it again?

[Lwiddis]

No experience with 40 to 60 amp hour batteries. Not sure many RVers do.