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By belvedere502
#200092
I have an older TENS unit and need a battery. Std. battery is a BL-4C 720mah 3.7vdc LI-ion rechargeable. The batt leads are soldered into the unit's board. It is a very small battery. I cannot find a direct replacement.
I can find larger batteries with leads (will require a custom external mounting), but all have larger mah ratings. How much larger can I go before I burn up the hardware or my test subject?
Dr Fronkensteen
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By DanV
#200106
It's extremely unlikely that a larger capacity battery would affect your device - it will only consume what it needs.
By belvedere502
#200118
Thank you. I reasoned that this would be the case. But, I am an ME, so I thought that I should check with the ET's in the web.
By Valen
#200170
belvedere502 wrote: Tue Aug 21, 2018 3:11 pm I have an older TENS unit and need a battery. Std. battery is a BL-4C 720mah 3.7vdc LI-ion rechargeable. The batt leads are soldered into the unit's board. It is a very small battery. I cannot find a direct replacement....
Googled for "BL-4C Ebay" and got a cell-phone battery as a first hit. Are you sure you can't solder leads to the contacts on the side? True, you should be carefull not to heat them up too much. Or
to be totally safe Mcgyver some thin press-on pin-contacts in the case perhaps?

https://www.ebay.com/itm/Original-Genui ... 0675876950

And I'm no EE either (schooled as ME, IT-guy now). As long as the battery chemistry and battery voltage match a larger capacity will only enhance the endurance of your device.