"Portable" battery box

[paul_ottawa]

Hello,


Somewhat off topic for RV, but involves a bunch of the same principles.


I got to thinking about battery backups and generators when we lost power here for 4 days from a tornado that hit us in Ottawa (thankfully, we only had minimal damage to our house and even though a number of houses here were completely destroyed, no deaths and only a small number of injuries).


I was lucky to have a neighbour who got a generator in less than 24 hours, and was able to plug in my fridge and freezers so I did not lose much in the way of food, and to plug my router in to give me access to the internet (mobile internet was atrocious during the outage).


One of my friend's cousins had made up a box that had a 12V deep cycle battery in the bottom, then on top it had a 12V plug, voltage monitor with 2 USB chargers and an inverter. I thought this was a great setup for some "portable" power (as portable as a ~50lb battery in a box is), but then I got to thinking of the venting of the battery (specifically, how there was none).


I was thinking of making a similar setup, and came up with the following questions:


Battery venting: Is this only an issue while the battery is charging? Is there a chance for it to have to vent while discharging? I currently have a Kirkland deep cycle/marine battery for the trailer, would this be OK to use? Would an AGM battery be better for not venting, or would it be similar?


Battery charger: I only have a cheap Black and Decker trickle charger, which I used on the battery over the winter (and my battery had a bad cell the second year, so I don't know if that is related). I'm thinking having a better battery charger that can do both trickle charging (so I can leave it on all the time, preferably on a timer) and a full charge (so I can take the battery to somewhere that does have power and charge it up, or charge it up using a generator for nighttime usage). Any suggestions on a good charger? Would something like this: http://a.co/d/5ncrsUj (amazon.ca link) be good? This one http://a.co/d/94RE7L3 @ 4 amps would be slower to charge than the 5A one, correct? Are the NOCO ones any good: http://a.co/d/ajwnwRR ? The amperage ratings on them (4A, 5A, etc), I assume that is how "fast" they can charge, so that would be 4A/h, so a 100Ah battery would take 25hrs to charge (if it were fully depleted, which I know is dangerous for the battery).


Solar charging: I have 3x40W Coleman panels that I used to top up my battery when we camped without power (and to recharge my battery while powering my router with an inverter before the generator showed up). I'm assuming if I were using these (with the proper charge controller), I would probably want the battery vented.


Thanks,

Paul

[Vicr]

I'm an electrician. Why don't you just get a generator and have an electrician install a transfer switch instead of trying to invent something using the internet?

[Snapchen]

Paul;
You are correct, an AGM battery does not vent. Some can be mounted in any position such as the Optima batteries. Optima makes a good battery charger that works with all chemistries and will sometimes recover otherwise marginal batteries. If you are intent on creating a power source you might also consider an inverter with the 12 volt battery. It will allow you to plug in 120 volt appliances as well as the 12 volt powered devices.

[SloPoke]

Originally Posted by Vicr

I'm an electrician. Why don't you just get a generator and have an electrician install a transfer switch instead of trying to invent something using the internet?

^ ^ ^ ^ +2

The only thing that is going to last 4 days in a situation like that - is a backup generator and sufficient fuel.

[jimp]

Minn kota sells a plastic battery box with vents and a 12v dc charging port. Been available for years.

[ALJO]

x2 on Vicr. Yes on: install a transfer Switch.

Here we have once and a while power outage also, just recently of a wet snowstorm. it went out a couple of times, one time at least 4 hours. On a 3000 watt generator/Inverter, I run the furnace, Fridge, small deep freeze, and TV and Internet. All through a transfer switch. The Generator I just park it in the doorway of the garage with the exhaust towards the outside. Never use a generator indoors.

Do it the legal way, you don't want to send power back on the line, because then you are legal responsible for injuries or dead.