Frequently Asked Questions [FAQ]

One lead acid battery, a hydrometer, EDTA in its storage container with a bowl of mixed solution and a pipette and a ‘bag’ of EDTA as supplied.

One lead acid battery, a hydrometer, EDTA in its storage container with a bowl of mixed solution and a pipette and a ‘bag’ of EDTA as supplied.

A very good source of information is

This section is in the process of formation and will be based on questions asked by people who have either purchased a kit or made enquiries.

Can I leave the pulser attached to the battery?

Yes and no. The devices consume between 40-95mA and thus will eventually drain the battery. Thus they should be used in conjunction with a trickle charger.

They can be used without but you will need to monitor the battery voltage to ensure it doesn't drop below 10.5V.

** I know this may seem basic, and to some quite obvious, but...... When you use a battery charger with a battery you attach the charger leads to the battery prior to powering the battery charger up. Doing it the other way around won't harm the battery or charger but the spark created at the point of contact may ignite highly flammable hydrogen gas in badly ventilated spaces.

Following on from this piece of advice do not attach the pulser to a powered up charger directly. The pulser can be attached to the battery undergoing treatment as follows:-

Attach pulser directly to battery terminals (observing suitable precautions against sparks as noted on the Pulser page), check for signs of correct operation then apply the charger clips to the battery or

Connect the pulser to a battery already undergoing charge or about to be charged.

The point I wish to make is that the pulser should not be powered up by a charger independently of a battery, they don't like it (believe me). The peak voltage out of an 'unloaded' battery charger is likely to be in the region of 20V this will challenge the 15V Zener 'protecting' the 555

Can I connect the pulser using crocodile clips?

Yes you can however you will not gain the full advantage of the pulses generated.

All connections in this circuit should be fully soldered (not crimped) and by far the best connection to the battery is by a proper battery terminal clamp. This gives a much larger surface contact area.

Will the pulser work on every battery I try?

In a word NO.

If the battery to be treated is suffering mechanical damage, has been left outside to freeze in winter, refuses point blank to take a charge **, displays less than 10volts then recovery is unlikely.

Ideal candidate batteries are those in irregular use in boats, caravans and occasionally or infrequently used vehicles. Here a steady deterioration in battery performance will be usually be noticed unless a very rigid battery charging regime is followed or a pulser is used.

** I need to expand on this point and the instructions now supplied with these units will make things clearer.

If you put a battery on charge and it continues to charge at a high rate after 24 hours then, broadly speaking, it is not 'taking' a charge. A simple load test will show that all this charging has amounted to nothing.

Such batteries are not candidates for pulser treatment as the cause of the high charge rate is likely to be mechanical damage or severe sulphation which has already shorted two plates.

Thus the pulser will be operating in to a dead short and they are not designed to do this anymore than other bits of electronic equipment are.

I do not wish to sell devices to people where they believe the device will cure their problem when it won't.

How long will it take?

A general rule of thumb would be one day for each lb that the battery weighs.

How do I now when a battery is 'done'

A good question is this. Generally when you see no further increase in the battery terminal voltage and/ or the rise in electrolyte SG ceases or the peak detector reading steadies out.

Be aware that having a trickle charger attached will give a false reading so disconnect this first. I generally walk away for 10 minutes with the pulser left attached and then take a voltage reading.

Another way is to build a 'peak detector' circuit (see the BB for more details). I have now released a version of the pulser with this facility fitted, however the inclusion of an integral LCD display will mean this option costing at least another £12 or thereabouts.

Do I need the 'high power' version?

Again a hard question to answer, patience is a virtue that not all of us are blessed with (believe me I should know).

More knowledgeable people than me have determined that there would appear to be a limit to the effectiveness of the pulsing as volts/ amps go up. At one point people were going for parallel MOSFET's, inductors ranging from 5-10A.

This was believed to simply blast large lumps of sulphate off the plates and not allowing it to go back in to solution, effectively doing what EDTA does I suppose.

You could say that a basic pulser is OK for the patient type with a pretty good battery which they wish to maintain in a good condition over say the winter period.

If, however, you are beset with a well sulphated battery and want reasonably quick results or have a number of such batteries then the 'high power' version is probably for you.

I’ve heard about dendriting / mossing but what is it?

This was a new one to me and I’m simply passing on my understanding here.

Batteries subject to long term low level charging will sulphate, a likely consequence of this is that eventually a cell will become shorted.

Using a pulser should prevent this from happening.

The PIC pulser referred to elsewhere on this site will automatically generate a ‘short’ across the battery to help prevent this occurring.

If you have a battery which you suspect already has this problem you may like to try the following (at your own risk).

If you have a battery load tester or can get access to one, stick it on the battery a couple of times (allowing it to cool between times). This may ‘blast’ the short away. As you can imagine this is less likely to succeed the longer the problem has been developing.


This page to be expanded as time goes on.

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