Richard Daugird Posted October 19, 2022 Share Posted October 19, 2022 Ryobi has 150 watt inverters that run on a cordless tool battery. Could you run, say, an Emerson 29646 on one of these? https://www.amazon.com/150-Watt-Inverter-Generator-RYi150BG-Included/dp/B07S2TLY1J Quote Link to comment Share on other sites More sharing options...
David Allen Posted October 19, 2022 Share Posted October 19, 2022 Very likely that inverter will do very poorly powering a fan. These cheap inverters almost never produce a sine-wave AC waveform and work very poorly for any type of induction motor. Look for the terms "pure sine wave" or similar. Anything about "modified sine wave" or no markings at all will be a form of square-wave chopped DC output. Quote Link to comment Share on other sites More sharing options...
Arjun Saini Posted October 19, 2022 Share Posted October 19, 2022 Tried that running an 80s lasko, didn’t even try to power it it started and stopped, these inverters can’t produce enough juice! Quote Link to comment Share on other sites More sharing options...
Richard Daugird Posted October 19, 2022 Author Share Posted October 19, 2022 Yes it is square wave chopped, doesn't have enough watts anyway. I guess I really need to get a hot air fan to take with me to car shows! Quote Link to comment Share on other sites More sharing options...
Jim Kovar Posted October 20, 2022 Share Posted October 20, 2022 22 hours ago, David Allen said: These cheap inverters [modified sine wave]... work very poorly for any type of induction motor. Hi, David. I'd guess a universal (series) motor would be able to digest a modified sine wave better than an induction motor. Full wave rectified modified sine wave,... even better yet. Let's get Mikey... He won't eat it,... he hates everything. He likes it!, hey Mikey. Quote Link to comment Share on other sites More sharing options...
John Smalley Posted October 20, 2022 Share Posted October 20, 2022 Milwaukee makes a battery powered fan model # 0886-20 Quote Link to comment Share on other sites More sharing options...
Arjun Saini Posted October 20, 2022 Share Posted October 20, 2022 19 hours ago, Richard Daugird said: Yes it is square wave chopped, doesn't have enough watts anyway. I guess I really need to get a hot air fan to take with me to car shows! I got an idea, gas powered fan anyone? Quote Link to comment Share on other sites More sharing options...
David Yurko Posted October 20, 2022 Share Posted October 20, 2022 Get a 32 volt fan and a vintage delco light plant Quote Link to comment Share on other sites More sharing options...
Arjun Saini Posted October 20, 2022 Share Posted October 20, 2022 19 hours ago, Richard Daugird said: Yes it is square wave chopped, doesn't have enough watts anyway. I guess I really need to get a hot air fan to take with me to car shows! Richard, you got a small block Chevy? And a whole house fan with no motor? combine that into the hot rod shop fan 1 Quote Link to comment Share on other sites More sharing options...
David Allen Posted October 23, 2022 Share Posted October 23, 2022 If you want to run a fan from battery, something such as this would be ideal. https://gpelectric.com/products/1500-watt-industrial-pure-sine-wave-inverter/ It will follow the normal rules of any transformer-like device. With 12V input and 120V output, it has a 10:1 ratio. In other words, the voltage is multiplied by 10 as viewed going from the battery to the load; and the current is multiplied by 10 as viewed from the load to the battery. Watts of real-power will remain the same, minus the 5% efficiency loss. So, a resistive load such as a light bulb which draws 1 amp at 120V from the inverter will cause the inverter to draw 10 amps at 12V from the battery; plus efficiency losses. A 10 amp resistive load such as a coffee maker requires 100 amps from the battery, plus efficiency losses. AC Motor loads (even series / universal motors) have an inductive nature which can damage cheap inverters, but works well with pure-sine inverters. To predict the battery current demand for a motor through an inverter, you need to know the watts of power demand for the motor. Then use the formula:([Motor Power] / [battery Volts]) / [Inverter efficiency] = [Battery Amps] Motor Power is Watts as measured by a watt-meter which is aware of power factor; such as a Kill-A-Watt meter. This is not amps nor VA; and one cannot measure volts and amps separately to calculate this with an AC motor of any type. Inverter Efficiency is per-unit efficiency. If the inverter claims a 95% efficiency that is 0.95 per-unit. Per-unit (PU) is simply percent divided by 100. PU is "per one" whereas percent is "per 100." PU a common unit of measurement with electrical parameters. Most of the vintage tabletop fans use less than 100W, often a lot less. If your fan uses 40W of power, and your inverter is powered by a 12V battery, you can use the formula as follows: 40 W Power (measured with Kill-A-Watt) 0.95 Efficiency (from inverter documentation) 12V Battery (nominal battery voltage) (40/12)/0.95=3.51 Therefore, to run a fan requiring 40W from a 95% efficient inverter from a 12V battery, the battery will have to supply about 3.5 amps. For a 100W fan, you would be using about 8.8 A from the battery. If you have a fully charged 100AH 12V deep-cycle battery, it can supply 5A for 20 hours, based on the normal way they are rated. The higher the rate of discharge the less of the energy you recover from the battery, but if you stay within the current range for a 10 to 20 hour discharge, they reasonably hold true to the following formula: Run Time = (battery capacity) divided by (battery current) For the two examples of fans above, the 100AH 12V battery would support the fan as follows... 100 AH battery 40W fan 12V battery 95% efficient inverter100/((40/12)/0.95)=28 hours 100 AH battery 100W fan 12V battery 95% efficient inverter100/((100/12)/0.95)=11 hours (or slightly less because this is a higher rate of discharge than the 20 hour rate upon which the battery is rated) These numbers are just approximations, but they are probably "in the ballpark" for for not having actual equipment to test. Hope y'all found this interesting! 🙂 2 2 Quote Link to comment Share on other sites More sharing options...
Richard Daugird Posted October 25, 2022 Author Share Posted October 25, 2022 A battery such as this? https://www.batterysharks.com/12-Volt-100-Amp-Deep-Cycle-Battery-p/12v-100ah-dc_b12-100.htm?gclid=Cj0KCQjwkt6aBhDKARIsAAyeLJ21cQKDm1MXAHPrbgqhdYMqMEmiuTjMsq_qc5716urDBmtX78gB6eUaAowzEALw_wcB Quote Link to comment Share on other sites More sharing options...
David Allen Posted October 25, 2022 Share Posted October 25, 2022 3 hours ago, Richard Daugird said: A battery such as this? https://www.batterysharks.com/12-Volt-100-Amp-Deep-Cycle-Battery-p/12v-100ah-dc_b12-100.htm?gclid=Cj0KCQjwkt6aBhDKARIsAAyeLJ21cQKDm1MXAHPrbgqhdYMqMEmiuTjMsq_qc5716urDBmtX78gB6eUaAowzEALw_wcB Yep! That is exactly what I was thinking when making that previous post. 1 Quote Link to comment Share on other sites More sharing options...
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