Thinking about adding an inverter to H33
- Thread starter Juice6576
- Start date
I use one of those small plug in style inverters. It works well. The only caveat is that they eat a lot of juice. To remedy that problem I installed a separate battery (and charger) dedicated to the inverter and the back up bilge pump. Kill two birds....
It has enough AC power to watch a little TV before bed too.
It has enough AC power to watch a little TV before bed too.
The amount of power usage depends on the load. If you are looking for an inexpensive setup you might consider a 750 Watt unit. Northern Tools has one on sale for $56. Anything over 400 W needs to be hardwired and fused. The 12V plug in units do under perform because of the loose connection. These inexpensive units are OK as long as they are installed in a dry place. They do need to be close to the batteries to minimize the wire lengths and voltage drop. The 120v circuit can be efficiently extended to provide power at the desired location with the use of extension cords. I would install a buss 150A fuse in the (+) wire and an On/Off battery switch to disconnect power when unattended. For around $100 you can have the full installation with adequate usable ac power. These inverters will usually have an inefficiency factor of around 15% so it plus the load will account for most power usage.
I would want to know how much the CPAP machine draws before I went and bought a too small inverter. It should have a data plate near the AC power cord indicating the watts or AC 120 volt amps needed to run it. if it lists the amps then (P=IV) the watts would be amps times 120 volts.
Cheap
Those small cheap inverters generate lots of heat and can melt
the wiring and the unit it also depending on the draw and ask why I know.
Nick
Those small cheap inverters generate lots of heat and can melt the wiring and the unit it also depending on the draw and ask why I know.
Nick
On our H33 we use a 300W AIMS pure sine inverter as a plugin, and have also hard wired a 2000W Samlex pure sine inverter, primarily to run the microwave when anchored.
With inverters you have to be concerned with the no-load current of the inverter generally the bigger the inverter capacity, the larger the no load input current willl be. The No-load current of the Samlex is specified at less than 0.9 amps which isn't too bad but it senses "no load" and therefore is probably lower than "idle with" a small load. The 300W unit is around 0.5a with no load.
The Samlex comes with a remote panel which displays the input dc voltage and the load power in watts, its only fault, is its load controlled fan, which when it turns on, sounds like a large vacuum cleaner! Luckily a microwave is only used for a short time, but it cycles on-off even with a laptop as its only load ~60W.
Also you must size the the inverter for more than the rated watts of the load, Samulex specifies 2:1 for a microwave, 3:1 for electric motors, 5:1 for an air conditioner. TV's, lighting, and coffee makers are probably 1:1.
For charging phones and tablets I prefer to use 12v USB plugin adapters.
Interestingly the touch screens on my tablet and phones don't work well when plugged in to the 300W inverter. My laptop works well when plugged in though.
The annoyance of the 300W unit is it starts beeping its low voltage warning when batteries drop below 12.1 volts! Much too soon, I believe it its spec is 11.0 volts +or - .5v, it used to work better, but....
To sum up from my experience one size does not fit all, unless idle current is low enough, also operation under full load should be quiet. Another plus would be sealed unit but the H33 environment is fairly benign under the starboard setee. I use only pure sine wave inverters and have no experience with modified sine or square wave units.
Any questions?
Not sure if it's relevant, but we hooked up a big diesel truck 12V battery to a 20 watt(ish) solar panel during the Haiti earthquake relief efforts with a small Cobra Marine DC/AC converter for CPAPS folks. I remember the brand because I had an old Cobra chart plotter and inverter in my old boat. I think we had about 4/5 extension cords going out to the machines to the folks (sleeping on the ground outside the US Embassy). No problems for a week.... long term, no idea....
Be careful with the quality of the inverter. In most modern inverters, you have two main options, which largely dictate price; pure sine wave, or a "modified" / "square stepped" sine wave inverter. If you're running sensitive (or expensive) electronics, you'll want an inverter with a pure sine wave. This is the quality and same type of power delivered to your home.
Cheaper inverters almost always have stepped sine wave power, which will power most things, but will very likely fry items like laptop power supplies, cordless battery chargers, and possibly microwaves/tv's - pretty much anything that uses a circuit board. It may not immediately damage them, but you can expect a greatly shortened service life of electronics plugged into stepped sine wave inverters.
On my 326, I had a Magnum 2,000 watt inverter/charger installed last season, upgrading the house bank to a single 8D battery. It's more than enough to power the stock microwave. I've been very pleased by the setup.
Cheaper inverters almost always have stepped sine wave power, which will power most things, but will very likely fry items like laptop power supplies, cordless battery chargers, and possibly microwaves/tv's - pretty much anything that uses a circuit board. It may not immediately damage them, but you can expect a greatly shortened service life of electronics plugged into stepped sine wave inverters.
On my 326, I had a Magnum 2,000 watt inverter/charger installed last season, upgrading the house bank to a single 8D battery. It's more than enough to power the stock microwave. I've been very pleased by the setup.
I bought a 12 volt power cord for my inverter. Had to pay $80 no insurance coverage, but much cheaper than an inverter.