Inverter Batteries R.I.P.

Handling 110 VAC wrong? Uncomfortable to the touch. Handling 220 VAC wrong? BIG BOOM ; like rcrapps said, never, ever, let the two hot leads touch, and especially don't be their conductor.

I'm not the real experienced one here but here are a few basic's: your hot water heater draws probably not more than about 10amps because the voltage is higher around 115V AC. Your inverter amp draw is in DC and can be a much higher number since it is much less voltage, i.e. 12 volts. The batteries that supply the inverter are rated often in CCA 'cold cranking amps' which starts ordinarily at 500+ for the small batt's.

This “Rule of Thumb” is intended as a general guide for estimating the DC amps required operating a DC to AC inverter. Since the calculations yield approximate values, an appropriate safety factor should be considered when designing and specifying system components, for example: wire, size, and length. This basicly is legalese for "oversise your system"

12 Volt DC Systems

Formula: 12 volt inverters require approximately ten (10) amps DC input for each 100 watts output power used to operate an AC load.

Example: How many DC amps will a 12-volt inverter require to operate three 500-watt quartz lights, or a 1500-watt electric heater?

Answer:

1) Total watts = 1500
2) 1500 watts/100 (from formula) = 15
3) 15 X 10 amps (from formula) = 150 amps.
This is the DC current the inverter will use to operate the 1500-watt load. Note; If these 150 amps are drawn from the battery for one hour, 150 amp hours of battery power will be used.

To support 150 amp hours of battery power 300 amps of battery capacity should be used for maximum battery life and performance.

That's dc from the battery.A Water heater draws about seventeen amps. You Never want to put a water heater on the inverter. If it's on there it was not done correctly and needs to be removed.

Would need a really big capacity inverter to start putting out 20 amps plus of ac.
My 240 V at 15 amps draws close to 90 amps of dc at 32 v

You never want a water heater or battery charger or stove/ovan on the inverter.

I have used my micro wave and two batt chargers on my inverter, so, what's the issue ??. past 10 yrs with no issues here.
What's your source ?

First: What are we talking about. Using inverter systems to condition shore power, or to generate AC from a DC battery bank?

Running battery chargers of an inverter drawing energy from a battery bank has not necessarily the desired effect.

Water heaters and ovens are high power devices.
The "generic" inverter installation is quite small, esp. the battery bank part of it.

The more obvious part is the sizing of the inverter itself (and it's cabling!).
The less obvious part is that a water heater or oven is very well able to drain a battery bank in short order.

Using an electric kettle to boil water, or a microwave to heat a meal is less of a problem since it's only a small a small amount of time.

(Using the divide by 10 rule of tumb which includes inverter losses.)

Boiling 1 liter (roughly 1 quart) of water needs ~0.1 kWh or 100Wh -> ~10Ah
Reheating something in a 900W microwave for 90 seconds. ~0.022kWh or 22Wh -> 2.2 Ah


So that is not so much of a problem.

Our 11-gallon water heater is rated at 15 amps (AC). The 6-gallon version from the same company is also rated at 15 amps.

-Chris

Hi,

The current draw (Amps) will be entirely dependent upon the voltage supplying the element.

The element will have a rating in watts and the same wattage element can be used in different size heaters, the 11gal heater will take longer to heat from cold if using the same size and number of elements.

Years of experience . These items will not damage the inverter. It is senseless to have them running on it. They drain the batteries way too fast with no big advantage. Especially battery chargers. Inverters are about 89% efficient. Why would you want to drain one battery bank to charge another and loose 11% in the process. A good install will separate circuits in the AC panel so that can't happen. A little time consuming but worth it. I've always told my customers to use the inverter for lite loads and start the gen for cooking and heating water. That way you get what you want, don't drain your inverter batteries in the process and even charge them while you are doing it. Inverters are wonderful and trouble free if installed right and used right.

analytic systems 240 V 2500 watt pure sine wave, LV protection, 32v dc source, used mostly when underway , can charge two 12v batteries etc with no problems, monitored use is the key as well as good equipment.

Don't believe that. The gen should never turn off because the inverter kicks into float charge when the batteries are charged. It is always putting a small charge into the batteries.