BCM Community

So I need some advice on running batteries to an inverter I have a couple floresent lights a coffee maker a 800 watt micro wave ,tv dvd and a stereo system Ive got a AIMS 5000/10000 watt inverter Im running 2 new bus batteries to it, should I run more these are not hooked to the bus batteries any advice  Im also looking at the honda 3000ie generator not sure if it will run my single ac ??? Thanks for your time JPULLEN

amps X volts = watt    a typical roof top will pull close to 15 amps  X 120 volts + 1600 watt continious  operation. plus surge for start up. Could run but would not be for very long maybe 1 hr. Sean can put math to it mine is only ruff guestimate.    was talking about inverter.        Gen set is like BW said a differant subject as to time of operation. Should have a peak rating and a continious rateing do your addition and select as to your needs.

I have the Yamaha 3000, it'll run a roof air no sweat. It'll run two if you put it through a Trace 4024, with a few amps to spare.

happy coaching!
buswarrior

If you have two "bus batteries" I'm going to assume you have two 230 AH batteries.  If the AIM, which is a large MSW inverter, is running from the batteries not connected to the bus, then you have 460 AH of capacity at 12 volt nominal, or 230 AH at 24 volt nominal (which I highly recommend to lower the DC current requirement) of which you should plan to never use more than 50% or risk damaging the batteries.  Your load is looking like this - constant load of the lights, TV, DVD, Stereo will add up to about 250 - 300 watts or so (do the math for your actual stuff).  The intermittent load will be the coffee maker at 1000 watts and the microwave at 800 watts, again check your stuff for actual numbers. 

What you do is this:  You have 230 AH at 24 volts, which can be said to be 5520 watt-hours.  The inverter will be about 90% efficient, so you have around 4950 watt-hours after you turn it into 120VAC.  You have access to half that, or 2475 watt-hours.  Your constant load is around 300 watts, so you can run the lights, the stereo, the TV and the DVD player all at the same time for around 8 hours and 15 minutes before you drain your batteries to 50%.  On the intermittent loads, running the coffee maker for 15 minutes to brew a pot of coffee (do NOT leave the hot plate on, use a thermos) will use up 250 watts of your 2475 total, and using the microwave for 2 minutes to make popcorn or heat up your cup of coffee will use up around 30 watts.

Your microwave may object to running from the MSW inverter, they don't like them.  Everything else you mention will be fine, they don't really care.  If you decide to run your rooftop AC unit from the inverter and the batteries, it will draw around 1800 watts per hour, so your batteries will last around an hour and 20 minutes if nothing else is running.  Also, the AC unit motors don't like MSW power either, they will run hotter and be less efficient, and wear out faster.  Keep in mind that the AIMS inverter will draw the batteries down below 12 volts before it quits trying with a low voltage alarm, and that is considered bad for the batteries.  50% state of charge under a moderate load is usually thought of as around 12.1 volts.

I hope this helps.  If you can run the inverter from your bus alternator, that would let you run the stuff, including the rooftop AC, for as long as the bus engine is running.  I run my inverter (Samlex 3000 watt pure sine) from a 230AH 24 volt battery bank, and from the bus alternator while the engine is running, and I run almost the same loads as you do, including the rooftop AC when the bus is running.  I've had no issues at all with the setup.

Brian

Wow I need to do some research I have a red wire and a  black wire and a inverter Did nt know there was different ways to make these things work Anyone have a diagram ???? Thanks for your time JAY