Regen Battery -To Pack Or Not To Pack

AG1500S ReGen Battery

“Do I need a battery pack to go with my ReGenerator?” is a commonly asked question. Well the answer depends upon what you’re trying to achieve. The ReGen battery allows the AG1500S to continue to provide power in the event of a mains power outage. In some circumstances this is essential and in others not so. First you need to understand how a ReGenerator operates.

Under The Hood


The essence of the AG1500S is based on the very latest in Uninterruptible Power Supply (UPS) technology. More exactly it is based on what is termed online double conversion or VFI technology.

Schema diagram for AG1500S ReGen

The incoming AC power feeds a charger which charges and keeps the batteries maintained (if they are fitted). It also generates the DC Bus via an AC Boost Circuit. In between the AC Boost Circuit and the source is a “Backfeed Relay”. We’ll learn more about this later.

The DC bus is a high voltage positive and negative internal power supply rail that the inverter uses to create the AC output power waveform.

The microprocessor controls everything (including the inverter but this isn’t shown for clarity). It constantly monitors the incoming AC power waveform and should it find the power to go out of tolerance it will instantly transfer power from the AC Boost, to the DC Boost and open the back feed relay. Power is then drawn from the battery via the DC Boost circuit. The net result is that the inverter sees no change of any note in the DC Bus and continues to provide power as normal. There is no break, or change as far as the output power is concerned.

What if I don’t have the ReGen Battery Fitted?

In the event of an out of tolerance input power (note out of tolerance means too high, too low, or non-existent voltage, or frequency) the ReGen will switch over from AC source to DC source (the battery). It will do this extremely quickly and will not revert back to AC Power until several seconds after the source is back in tolerance.

If no battery is connected, then the ReGen will detect a low battery condition and simply switch off. Since low battery is classed as an alarm, you may hear the ReGen emit a “dying” tone.

There are power problems which are known as a micro-outages or voltage sags. These are very momentary dips or breaks in power that may not be overly noticeable, but the AG1500S will detect them and transfer to battery to prevent any loss of power. Since the unit will not revert back to AC power until several seconds after the AC power source is restored, the unit will detect low battery and switch off. In such instances it looks like the ReGen has simply switched off for no reason. But there is a reason, and that reason is that there is a power anomaly that the ReGen is designed to prevent getting through to your load. It won’t allow any break or variance from the pure waveform it is intended to deliver.

When the ReGen Battery is fitted, the unit will seamlessly transfer from AC power to the DC power and continue to power your load without any interruption at all. If it isn’t fitted, then the ReGen will switch off when the power is out of tolerance, regardless of how short that power anomaly may be.

Backfeed Relay

You might wonder why I wanted to mention the backfeed relay. This component is in the circuit primarily for safety. What is does is physically disconnect the input power conductors from the unit. This is to prevent the possibility of the output power appearing on the pins of a mains plug should you pull it from the socket – ouch!

Backfeed Relay

In normal operation the relay is closed, connecting Live and Neutral to the ReGen circuits. Should the AC power fail the unit opens the relay contacts from both the live and neutral conductors. This isolates the output from the input.

Some say, this is great for audio applications! But, sorry there is a but, it requires running the unit for prolonged period on battery. There are two issues regarding this. Firstly, if the power consumption is quite high, the length of time the batteries would last is quite reduced. For example if you had a fairly low powered system of say, 50W , you could run this for over 6 hours! However a 500W system would last just over half an hour. Perhaps not long enough!

Secondly, if you were planning on doing this regularly, then you should note that lead acid batteries as used in the ReGen Battery only have a finite number of charge and discharge cycles of 200-300, which means you could be replacing the battery pack each year. If the batteries are not fully discharged, then you will get a lot longer – typically between 3 and 5 years.


The AG1500S will work without the ReGen Battery pack. It will provide a pure stable output power waveform at all times. However, if the power should fail even momentarily the AG1500 switches off.

So if you need the in-built UPS capability of the AG1500S, or want to run your system truly isolated from the “real world”, then you should consider the ReGen Battery. Available on our online store.

New AC Power ReGenerator – AG1500S

AG1500S LCD Display

The AG1500S ReGenerator- What’s in a letter?

AG1500S AC Power ReGenerator

Due to be released in June the new AG1500S AC ReGenerator has built upon the success of the previous AG1500 model with some major upgrades. So what difference does that extra letter make?

Selectable Voltage

AG1500S LCD DisplayPrevious ReGenerator units have had a fixed output voltage and frequency. For those travelling to places which operated on a 60Hz frequency this required a factory adjustment. The unit was suitable for either 50 or 60Hz but not both.

The new AG1500S auto detects the frequency and adjusts itself automagically, allowing for the unit to be operated in any area.

As well as the frequency improvement, the output voltage can now be adjusted. The AG1500S can be set to output 208V, 220V, 230V or 240V, via the LCD panel, depending upon your requirements. Note as with the previous model the output voltage is fixed and unwavering.


Sine Wave

The earlier models were sine wave too of course with a Total Harmonic Distortion (THD) of under 3% and typically 2%. THD is simply a measure of how far away the output is from a pure sine wave, the lower the number the better. Anything lower than 8% can be called sine-wave.

The AG1500S has a THD of 2% and typically is 1%. This may seem a small change but it registers a substantial improvement in power quality. So much so, that our beta testers have said they thought the AG1500 was good, but the AG1500S is so much better.

Smart Fan Speed

fans spinning on ag1500s ac regeneratorFan speed is problematic of course as it generates noise. The standard way for fan speed control is to have the fan speed controlled by the amount of load the unit is delivering. However this leads to unnecessary increase in fan noise especially in audio environments where the load is not constant but rather has sharp peaks of demand. This is why we introduced a control mechanism in the original AG units, allowing you to set the fan speed depending upon your own set up and requirements. However, this can lead to the unit overheating and tripping out if set too low.

We’ve devised a novel way of controlling the fan speed with the speed adjusted automagically to the unit needs. If it’s getting hot the fans will speed up and slow down again when it cools. This way your ReGen won’t unexpectedly cut out and scream at you. Another feature we put in is that on power up the fans will ramp up to full speed for a few seconds and then revert to the appropriate setting. This way you can be confident that the fan circuitry is in good order – and if it isn’t the fans are defaulted to run at full speed so the unit can be used until a service can be arranged.

Super Cool

What’s more the unit efficiency has been improved to a remarkable 93% peak – which means the unit doesn’t generate as much heat in any case. In our lab tests, even running at a constant full load the fan noise was minimal. This high efficiency means the unit costs less to run as well as not pumping as much hot air into what may be an already warm environment.


AG1500S REar Panel


A big change from the AG1500 is the changeover to IEC socket outlets. Some liked the national socket outlet on the AG1500 but others found that this required the use of extension blocks as one socket wasn’t enough. So we’ve now got six of the IEC 10A socket outlets and one of the high current 16A outlets. The unit comes with a rewireable 16A plug allowing you to rewire your main cable. This of course means that there are no fuses in the output stages which we know is of importance to some users.

There’s also now a much smaller battery connection port to allow the connection of a separate battery pack. For those of you with existing ReGen battery packs please note the battery voltage is different and so they can not be interchanged (plus you would need to get a different cable adaptor).


We’re delighted with the performance of the AG1500S ReGenerator in our lab bench tests. The unit functionality, performance and robustness have all been put to the test and has come out with flying colours. We’ve had the unit out on test with a number of eager audiophiles who have reported extremely positive results using the AG1500S:

  •  “Overall it is a very well conceived unit and one that I certainly would recommend“,
  • This unit has made a significant difference, please put me on the list for a new one when released“,
  • So far I am confident the new unit is an improvement, it sounds cleaner at both ends of the spectrum, more dynamic and with a wider and deeper soundstage. The HF are smoother and more extended, the bass extends lower too and is tighter. Compared to my TX it is relatively close

We’ve currently got the demo unit out on review with a well known HiFi mag, so we’ll keep you updated with the results of that when it’s in.

Incidentally, the last comment above refers to our TX unit. Now this is not a ReGen but one of our isolated UPS Systems. The reviewer of the AG1500S said the TX was an improvement over the AG1500, but the AG1500S was close. Now the TX series is not quiet and not suitable for anything other than professional AV applications with a separate equipment room, so if you’re in this market the TX series may be an alternative for you.

The new AG1500S will have a retail price of £599 including VAT, delivered. I’ll let you into a secret though, since we’re 10 years old this year we’ve a promotion running  – get 10% off the AG1500S by using the discount code “10years” when asked in the order process. The code is valid until the end of August. Click for the AG1500S Webstore Page or to download the brochure.

AC ReGenerator Input Vs Output

What a great question received into technical support today:

Can you show the difference between the input and output voltage waveforms on the AC ReGenerator?

We have a bit of bespoke in-house test equipment that we use for looking at the quality of the mains supply. It allows us to view both normal and common mode noise levels, as well as viewing an AC power waveform. We can connect it to the output of the ReGenerator and show you a nice clean output waveform. We can also connect it to the input and show you another apparently clean input and output waveform, or a distorted waveform, or a clean high voltage waveform. The point is, the output of the ReGenerator is the same, regardless of the input waveform. If the input waveform is good, then this isn’t really showing us anything.

So what we have done is to create a secondary piece of test equipment that provides a distorted power waveform to the ReGenerator:

Distorted AC power waveform

This oscilloscope trace shows a pretty messed up AC power waveform, with a high Total Harmonic Distortion. Such a power waveform will cause untold problems with electronic systems, and with any inductive devices such as those containing transformers or motors. Any system requiring a quiet noise floor will be sadly disappointed as the noise levels will be remarkably high on the line to neutral. Any standard filter devices will redirect this to the earth resulting in common mode noise issues as well. Clearly not good for Audio Visual applications!


When we feed this power waveform into an AG500 ReGenerator, we get this at it’s output:

Power Inspired AG500 ReGenerator Output Waveform

See the harmonic distortion is eliminated! Not only protecting the inductive elements but ensuring that noise levels have improved dramatically. Exactly the sort of environment your AV equipment wants to see. This is the main difference between ReGenerators and filters. The ReGenerator recreates a new AC power waveform. A filter can only try to remove what shouldn’t be there.

Read more about the Power Inspired AG Series ReGenerators.

Buy online.

AC ReGenerator Fan Speed Control

Fan speed Control

When we first developed the ReGenerators, we knew that fan noise had to be kept to an absolute minimum. We went through countless tests with a variety of fans to compare sonic performance against the required airflow. After we found our perfect fan we needed to be able to control the speed – and hence the noise output. 

Fan press button fan speed controlAfter contemplating automatic fan speed control methods, all of which had some pro’s and con’s we finally we thought why not let the user adjust the fan speed to a setting they can live with? After all, music listening is very individual and if the ReGen gets too hot it does have a safety shut down device.

We incorporated this into the ReGens and allowed the user to adjust the speed potentiometer through a well positioned hole in the back plate. After a few instances of people mashing the POT by using a knife or something similar we included a jewellers screwdriver to do this adjustment.

This was still a bit fiddly and so we modified the mechanical design and included a spindle on the potentiometer. This made it much easier to adjust and this system worked well.

However, we like to keep developing new concepts and wanted a more elegant adjustment solution. We’ve now come up with a push button design and it works like this:

When the ReGen is powered up, the fans will spin at full speed for around 5 seconds and then slow down to the last setting used. It’s kind of like a start up test so you can observe the fan speed circuit is working correctly. If the last setting was full speed then the fan will stay at full speed. If the button is pressed momentarily, the fan speed will increase slightly with every press. If we press and hold the button the fan will increase to maximum speed and stay there until the button is released.

Now the fan’s at full speed if we now press the button momentarily the fan speed will decrease with every press. If we press and hold the button then the fan speed will decrease to minimum speed.

Once minimum speed is reached, if we keep the button pressed for over 2 seconds, then the unit will be set to 50% fan speed.

We think that it makes fan speed easier to adjust as all is needed is a button press. It’s also a very simple way of getting the unit to 50% fan speed which allows for consistency if the speed is regularly adjusted.

We’re always interested in hearing your opinions so please let me know if you have a view on this (or anything else you’d like to see for that matter).