ET-312 Battery

Has anyone replaced the battery on their 312? I have not opened mine up yet to see if the battery is soldered to a board, etc. Would like to know if it is a DYI project before jumping in to it. Thanks for any info...

I have had an ET 312B for years, but I'm still on the original battery.

Does the battery maintain its charge throughout an entire session or do you find you are having to rely the power adapter during the sessions?

Battery should hold for many sessions. If you think you have a problem PM me for who to contact.

The battery on an ET-312 is a high capacity sealed lead-acid battery which should happily charge over 1,000 times. The electronics will not let it over charge. If you are having problems put it on continuous charge for 24 hours and all should be well.

Hmm, my 312 works perfectly fine and last for (what seems like) hours without having to charge it 😃

To change the battery which should be available locally, The two or four screws in the bottom of the unit must be removed. then the face plate must be removed by pulling out the off/on button. It does pull straight out and off. Then pull the knobs off. You should then be able to split the case. be careful and gentle. the battery which is in the rear of the unit is held in place by a metal strap remove that andd disconnect the battery. Be gentle when reassembling the face.

Thank you for that information. The battery on our ET312B has certainly seen better days.

Our ET312B is real workhorse.

I've replaced the battery in mine. It's a bit tricky getting the box apart. The top and bottom halves both have attached components that protrude out the front panel, so the front panel winds up trapping the 2 halves together. Here's a YouTube video that shows how to get them apart. (It's in German, but you don't need to understand it to see how).

https://www.youtube.com/watch?v=y7SyuX9bXEE

And here's a discussion about it at SmartStim...

http://www.smartstim.com/forum/viewtopic.php?f=19&t=25964&st=0&sk=t&sd=a&hilit=et312+battery+replacement

The battery in these is a sealed lead-acid battery, same as ones used in security lighting systems and other battery powered emergency equipment. Consequently, like a car battery you have to keep it regularly topped off or it will sulfate and stop accepting a charge. I let mine sit untouched for about a year and a half and it killed the battery, which is why I wound up having to replace it.

If you need a new battery, you only need to get the old one out, take it to a Batteries Plus type store and they can cross-reference it, or you can do your homework and order one online yourself. They're not expensive. Getting one the exact same size is important or it won't fit the clamp inside.

If you're someone who uses it a lot, then you're probably charging it a lot, and you won't have to worry about this for a long time!

That's a great demonstration.

Thank you.

Yes, the video is really good, since you see exactly what you need to do, and what the inside looks like, so you know what movements to avoid. For example, the top half of the case is attached by a wide flat multi-channel electric cable, and has to be tipped forward -- not pulled straight upward when you've got it free from all the buttons and the control panel. Even the instructions don't make that clear, but the video shows you how to deftly do this.

It is a bit tricky getting the two halves free from the buttons. A thin plastic knife-like tool can help GENTLY lever the control panel away from the protruding buttons. Wiggling it a bit helps too. GENTLY.

If your battery seems to have stopped working, take my advice: check to see if your recharger is still working. Maybe the problem is not the battery, but the charger. If that's the case, buying a new battery will be a waste of a lot of money and time, since your old recharger won't be able to recharge the new battery either. Yes, they actually can go bad -- as I learned the hard way (and now I have an extra new battery that I didn't need).

I'm not sure what is the best way to test your recharger. One way would be to take your unit to a place that sells rechargers (and has the exact one needed). If they will let you try charging your unit for a short time, you could see whether the unit is then being charged -- and if so then there is nothing really wrong with the battery; it's the recharger that needs replacing. Just attempt to let it recharge for a short while, and then test if the unit has recharged enough to indicate an increase in the power available, or that you can actually turn it on, get a good reading, and see (feel) whether you are getting the usual signal output. If that's so, then it's that new recharger that you need to buy -- not the battery.

ErosTek sells both new batteries and/or rechargers.