Possible way to improve inverters ability to start large loads ? Car stereo big capacitor.

[32 volt boater]

In the car stereo world they put large capacitors on the DC side for when the bass hits.

These big capacitors store electricity as instant power available for your amplifier. If the amplifier draws more current than is available from the electrical system directly, the capacitor covers the difference up to its stored capacity. The battery is not overloaded and the car voltage remains steady.

4.0 Farad Power Capacitor LED Voltage Display Power Cap Car Audio Amplifier Capacitor Car Accessories for systems up to 2000W​

I think that maybe inverters often fail to start big AC motor loads is because the voltage on the DC side drops too much. I don't know what would happen big capacitor on the DC side of an inverter. Might work awesome, do nothing or might fry it. Don't know.

Speakers and AC electric motors, both got coils of wire to make magnetic forces.

 

[Bobert]

Soft starts are used for rv roof ac units. Recently they released a whole rv version that plugs into the shore power pedestal.

 

[32 volt boater]

Soft starts are used for rv roof ac units. Recently they released a whole rv version that plugs into the shore power pedestal.

Here is how they work, very very detailed article https://sound-au.com/articles/soft-start.htm (The circuits and techniques described here require experience with mains wiring. Do not attempt construction unless experienced and capable.) OK,

Photo of inside one,



Capacitors seem to play a large role.

I am out the door, I am going to read the link above tonight.

 

[toms]

As you can see, on the right hand side of my auxiliary install is a maxwell supercap.

What a supercap does is reduce the current draw on the LiFePO4 during inductive load startup. It does also eliminate AC ripple when AC based charging occurs.

What it doesn’t change is the inverter size required to cover the startup surge.

 

[cs1234]

As you can see, on the right hand side of my auxiliary install is a maxwell supercap.

What a supercap does is reduce the current draw on the LiFePO4 during inductive load startup. It does also eliminate AC ripple when AC based charging occurs.

What it doesn’t change is the inverter size required to cover the startup surge.

Where did you get the Maxwells?

 

[32 volt boater]

As you can see, on the right hand side of my auxiliary install is a maxwell supercap.

What a supercap does is reduce the current draw on the LiFePO4 during inductive load startup. It does also eliminate AC ripple when AC based charging occurs.

What it doesn’t change is the inverter size required to cover the startup surge.

I can never think of anything first !

 

[toms]

Where did you get the Maxwells?

An Australian distributor of second hand units. FPV-Power.

 

[cs1234]

An Australian distributor of second hand units. FPV-Power.

Yeah, I've seen them also. Can't imagine the cost trying to get them to ship to the states though.

 

[toms]

Yeah, I've seen them also. Can't imagine the cost trying to get them to ship to the states though.

These originally come from the USA, so there must be someone selling them there.

 

[time2roll]

Has someone documented this issue for LFP battery?
Seems like it would be more suited to limitations of FLA.

 

[Lilikoi_Heavy_Industries]

I don't have voltage drop issues anymore, but I would consider adding capacitors if I saw high dc ripple warnings, possibly.

I don't use redflow batteries (exotic chemistry?), but otherwise here's an example of how to add additional DC capacitors to my inverter. It doesn't look expensive and there are no PCBs like what is linked earlier in the thread.

https://redflow.zendesk.com/hc/en-us/articles/360039311291-Additional-DC-Capacitors-required-for-MultiPlus-II-product-series-when-used-with-Redflow-ZBM2-ZCell-batteries

It sounds like the modification is designed to put a MultiplusII on par with the previous version Multiplus charger/inverter DC caps.

 

[meetyg]

Battery Hookup has these 48v Super Caps:

48v 18x 2.7v 3000F 3.038wh Nesscap Ultra-Capacitors 1,000,000 Cycles

When you want to let people know that you don't mess around, you need this ultra-capacitor module. It has 18 Nesscap 2.7v 3000F 3.038wh cells already welded in series for a 48v battery. You could also convert these into 6s or 5s modules for car audio. Usually these capacitors are $50 each brand...

batteryhookup.com

 

[JBertok]

I ran a 90 Farad automotive supercapacitor with my Trace SW2512 for years before decommissioning that inverter earlier this year. It legitimately reduced the rapid pulsation of charge/discharge to and from the battery as the inverter created the AC waveform. Without the supercapacitor, a permanent magnet held in your hand between the 4/0 positive and negative battery cables would actually dance from vibrating so hard. The capacitor smoothed that right out and it had to be better for battery health and efficiency overall. The supercapacitor was connected to the DC bus very close to the inverter, and during operation at full load would even become very warm from all the work it was doing.
These things are available on Amazon and Ebay but be aware they are only rated for 15V. They have an internal disconnect switch that's used in making the initial electrical connection, and I used that switch to disconnect it during an equalization cycle. (I have that thing on my Tahoe now and when charged is strong enough to crank and start a 454 without the battery at all.)

 

[JBertok]

Battery Hookup has these 48v Super Caps:

48v 18x 2.7v 3000F 3.038wh Nesscap Ultra-Capacitors 1,000,000 Cycles

When you want to let people know that you don't mess around, you need this ultra-capacitor module. It has 18 Nesscap 2.7v 3000F 3.038wh cells already welded in series for a 48v battery. You could also convert these into 6s or 5s modules for car audio. Usually these capacitors are $50 each brand...

batteryhookup.com

That is awesome. Wish they'd make it in a 24-cap version for 48V DC nominal systems. Looks like rated voltage is 48.6V with surge up to 51.3V for the pack. My system is hitting 59V daily and 62 during equalize. Would be comfortable manually disconnecting it with a breaker during equalize, but not running it every day at those specs. Really needs 24 ultracaps (64.8V) in series to safely avoid overvolt. I suppose at that price it would be worthwhile to buy two units and make one bigger.

 

[chess-equality]

As you can see, on the right hand side of my auxiliary install is a maxwell supercap.

What a supercap does is reduce the current draw on the LiFePO4 during inductive load startup. It does also eliminate AC ripple when AC based charging occurs.

What it doesn’t change is the inverter size required to cover the startup surge.

Would you have some wiring diagram links that you can share? Thanks.

I have a 12v battery with a finicky BMS that doesn't particularly like the startup surge when I turn on my PC.

I have been checking below but it looks scary, looks bigger than a battery

American MAXWELL Super Farah Capacitor Module 48V165F Hybrid Electric Vehicle | Lazada PH

Ats Automatic Transfer Switch for Generator: Motors, lithium battery, power heats, etc. Ats Automatic Transfer Switch for Solar: Solar, micro charge, polyvinyl chloride, etc. Kroak Super Capacitor Jump Starter 400F: Rated; voltage: 48v 1616. Electrical Tools and Equipment All Set: Includes...

www.lazada.com.ph

 

[toms]

Would you have some wiring diagram links that you can share? Thanks.

I have a 12v battery with a finicky BMS that doesn't particularly like the startup surge when I turn on my PC.

I have been checking below but it looks scary, looks bigger than a battery

American MAXWELL Super Farah Capacitor Module 48V165F Hybrid Electric Vehicle | Lazada PH

Ats Automatic Transfer Switch for Generator: Motors, lithium battery, power heats, etc. Ats Automatic Transfer Switch for Solar: Solar, micro charge, polyvinyl chloride, etc. Kroak Super Capacitor Jump Starter 400F: Rated; voltage: 48v 1616. Electrical Tools and Equipment All Set: Includes...

www.lazada.com.ph

For a 12V system you need a 16V supercap (if you look at my system there is a 48V and 16V in series).

Wiring is system dependent. It basically goes in parallel with the battery, but you need over current protection between the two in case they disconnect and then the fully discharged supercap is reconnected.

 

[JBertok]

Pulled the trigger on x24 2.7V 3500F Nesscap supercapacitors. Will be building a custom box or something to hold them, and connecting to PDP DC bus through a 250A Schneider breaker, and a charge/discharge resistor circuit. Should be here the third week of September. Will report back.