Would a large capacitor assist battery bank/inverter?

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supermanotorious

supermanotorious

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I've been wondering for a while now, adding a large capacitor next to the inverter, would that help when appliances start up and require momentary high wattage? Batteries are designed to release steady over time, caps give quick large bursts.


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All RV appliances are designed for "standard" RV battery systems,, why would you need "quick large bursts"<>>>Dan ( Evan DC current travels at the speed of light)
 
Don't think it would make any difference unless your appliance is drawing more than the rated output of the battery for that few milliseconds.

Lead acid batteries recover fairly quickly to heavy draws. 

utahclaimjumper - any time you turn on a motor or electric heater (like those used in RV fridges), there is about a 15% overdraw (over the rated draw) from the appliance.    It's not that you need "quick large burst", but rather the appliances are drawing quick large burst when they start up.

 
utahclaimjumper said:
All RV appliances are designed for "standard" RV battery systems,, why would you need "quick large bursts"<>>>Dan ( Evan DC current travels at the speed of light)
Click to expand...

If I remember correctly, he has a residential fridge running off of an inverter.
 
The capacitor would have to be mounted as close as possible to the inverter 12 V input terminals with large wire to be effective.  This might help to make the inverter operate with smaller input wire. Placing it at the battery end wouldn't make much or any difference. I would want to be able to return it if it doesn't work. The 10 Farad capacitor would be the one to start with. I would change the input wire to at least #4 although I have better confidence with #0 before I would try the capacitor.
 
When I had to send my Prosine in under warranty they told me that on power up it sucks BIG time power.  If only to make sure the batteries can provide.

THey told me to tape the positive and negative wires side by side to cut down on the effercts of inductance.. I did, and well, over a decade later I'm back in failure modes (The original failure took less than a year) So I'm basically pleased.

Why do I point this out.

A great big multi-farad "hardenind capicator" right at the inverter.... can't hurt.  May help. 

THat said I won't make a recommendation,  IF you choose to try it, let us know how it works out.
 
If the battery capacity is marginal for the loads, I guess a capacitor might help, but wouldn't it make more sense to just make sure the battery can handle the peak load? When you probably are going to want the capacity anyway for longer run times?  If we were talking about a/c compressors I can see the point, but for a fridge?

An alternative to a capacitor would be to use automotive-type batteries or marine/RV batteries, both of which ARE designed for brief bursts of high amps moreso than sustained power. After all, a battery is essentially a capacitor. The difference between deep cycle and automotive batteries is basically just the amount of plate surface and the spacing.
 
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