8.4V (9V form factor) mercury battery substitution

[alanrockwood]

Hi,

I have a flash meter that uses a E146X battery. This is a 8.4V mercury battery that is no longer available. It looks like a regular 9V transistor radio battery, but it is only 1.75 inches tall (44.5mm), which is a little shorter than a regular 9V battery. I am looking for a substitute. There are some 8.4V batteries out there, but they are the size of a regular 9V battery, not the sllightly smaller E146X battery. Does anyone know of of a substitute battery?

Thanks.

 

[Johnkpap]

First answer buy a new flash meter

Next option modify the meter so a standard 9v fits and solder in a diode

Minolta makes/did make a number of nice flash meters

Johnkpap

 

[alanrockwood]

First answer buy a new flash meter

Next option modify the meter so a standard 9v fits and solder in a diode

Minolta makes/did make a number of nice flash meters

Johnkpap

Yes, I think a new flash meter is the best option.

Modifying a standard 9V using a diode won't work in this case because a regular 9V battery is too long to fit in the meter. It needs to be about 3.3mm shorter than a regular 9V battery in order to fit.

 

[bernard_L]

Assuming you won't be using your flashmeter during a hike or in a similar situation, the solution need not be totally compact.

• Easiest: use a wall-plug 9V DC supply, and wire it to the battery terminals through a small hole in the battery compartment door. Obviously for studio or other indoor situations.
• Small 12V battery, for garage door remote, A23 or A27, plus a voltage regulator (e.g.: LM317). You may have to accept that this power source is dangling at the end of short wire outside the case of your flashmeter.
  
• Stack three 3V button cell batteries CR2032 or similar in a DIY holder, to provide 9V; I don't believe that the difference between 9V and 8.4 matters at all.

 

[AgX]

I would consider making a battery myself by either stacking 1.3V Zn/air cells or by stacking 1.5V cells. In the latter case you even couls insert a voltage dropping diode.
Another approach would be soldering a 9V clip w. cable to the contacts inside the meter and attach a 9V battery to the meter underside, by doublesided adhesive tape.


By the way, first time I hear of a such 8.4 battery in the shape of a 9V battery. Unknown over here.

 

[John Koehrer]

Since you have 8.4V batteries available why not use the hole (post #4) and wire it in? 9V connectors
are simple to find.

 

[Dan Fromm]

Funny, I just looked at Energizer's specs for their E146x Mercury battery (8.4v) and their 522 Alcaline battery (9v). They're identical.

 

[shutterfinger]

Pay attention to the amp hour rating as a lower rated battery may not power the meter or require frequent replacement.