LEARNING, and fine tuning my system-HELP!

[joerossjr]

Ok, here's my first post:

https://www.solarpaneltalk.com/forum...he-gear-i-have

So I have added an EXIDE 31MDC 115AH 12V Battery and removed all the old UPS batteries. I have it wired as 12V right now, I think I am going to try to find another one and get it up to 24V. (This is an FLA battery?) I do understand that I am pretty under powered right now, I'll address that in the near future.

I am thinking if I get all the DC power supply electronics, I can step down the voltage to whatever I need, and only use the inverter for the AC items I require (right now that's just a Slow-cooker.) I should be able to juggle the AC device usage until I decide how the setup needs improved.


Here are my questions:

Will a 24V 500W inverter be a good starter? 260W was the largest load I anticipate before I do some real testing and get real world usage. Any recommendations on a 24V 500W inverter? I can't seem to find a decent affordable model.

I planned to use step-down power supplies for all the phone, tablets, and laptops? What do I need to know about these? Any recommendations?

[Logan005]

I use two similar battery for my backup system, wired in series with a Samlex 2415 smart charger. and two 24 to 12 step downs for about 110 watts of security equipment. Cameras and DVR's can run for several hours of grid fail. I have not fully cycled it yet. just for a few min's at a time when grid lapses. A 500 watt inverter at 24 volts is ideal, especially if you only use half of it. There are many step down converters on E-bay, some for golf carts, Marine applications and some for hobbyist. However I have found all of them allow for 22 volts or lower LVD, this is too low, and should be set for 24 volts, to keep batteries healthy. You will need a separate LVD to prevent over discharge. I was able to find step down converters for all of my devices, 24 to 19 @ 3.74 amp for my big screen TV and my laptop. When you finally upgrade to 48 volts, you will just need to buy 48 volt converters, I kept all of mine for future use. I would not use an electric slow cooker, .Coleman makes a propane slow cooker and another company makes a slow cooker, you heat on the gas stove for a few min's. and then set aside to finish w/o any additional heat. Coffee should also be made on a gas stove or wood stove in season. I have a friend who uses battery to power his electric drip coffee, but he uses an insulated crafe not the heating element that has been disconnected.

[joerossjr]

I use two similar battery for my backup system, wired in series with a Samlex 2415 smart charger.

Charger? I intend on using Solar panels, I doubt that will make too much difference once I get the component sizing correct. (1 night with no outage is a good start!!) Did you have a model or brand suggestion for a 24V DC inverter? I am not finding one. Is 24V/500W an uncommon size?

There are many step down converters on E-bay

Are they stable enough to power a laptop @ 160W (19V*8A?) I have seen them at 19V/8A, but are they reliable? Some have Ameters, Voltmeters, POT adjustments... is there anything I should look for or avoid when looking for step-downs?

I would not use an electric slow cooker, .Coleman makes a propane slow cooker and another company makes a slow cooker, you heat on the gas stove for a few min's. and then set aside to finish w/o any additional heat. Coffee should also be made on a gas stove or wood stove in season.

I planned to look into DC versions of appliances... Thanks! I used a crockpot since it was handy and provided a pretty constant load.

[Logan005]

DC appliances have to be selected carefully. heating elements are not good to use with battery. You will want propane or wood cooking stove for cooking, toasting. boiling water. even a small microwave can use enough power to leave you in the dark. If you depend on the power from two of these excide batteries you will need to be much more careful, than to be running heating elements and microwave oven. You need to do a load to needs analysis, this involves learning to live off grid first, reduce your load and expectations. .less is more when it comes to battery replacement cost if you heavy cycle these two batteries, I doubt they last a year. You will also need to check the water and have distilled water to replace. These are not the best batteries for solar, but if you have a generator and charge then when solar fails, you will get best out of them. as far as step down converters, I like the Sealed fixed output units, no adjustment self cooling and easy to integrate. I have used a few others, careful choosing amps, make sure your Power Supply provides at least the appliance amp rating. no less! If you want microwave, drip coffee and crock pot, you will need bigger and better batteries.