Myoguide Power:  Alkaline Versus NiMH Rechargeable Batteries

Myoguide Battery Comparison

Even though the NiMH rechargeable batteries have a lower specified capacity (2300mAH) and lower voltage (1.2V) compared to a typical Duracell ProCell Alkaline AA battery (2850mAH, 1.5V), they tend to provide more capacity in a higher current draw situation. The following article covers Myoguide Battery Strategies to get the longest battery life.

NiMH rechargeable batteries provide a steadier discharge than an alkaline battery.  i.e. Alkaline batteries have a steeper discharge curve as the load current requirements increase.

The downside to using a NiMH rechargeable in the Myoguide is that the battery display icon is calibrated for a 1.5V (Alkaline) battery and hence when using NiMH rechargeables, the battery icon will only display ¾ full when the NiMH are at full charge and will show empty when batteries are 50% discharged.  i.e. The unit will run for quite a considerable time when the battery icon shows empty.

Myoguide Battery Low

Note: Due to the fact that battery discharge is not linear, but rather is logarithmic.  The battery detection circuit is designed to linearly display the current battery voltage; hence, the display is not a truly accurate rendition of the state of charge.  i.e. when the display shows one bar, there still may be considerable battery capacity remaining.  The batteries should be replaced when the display indicates “ Battery Low!”. This is one of the best Myoguide Battery Strategies.

Battery Test Comparison

Test 1:

80% EMG mode with 200Hz, 1mVp-p signal in, Vol:4.  20% Stimulation @ 1mA, 500uS pulse width, 1 Hz frequency into a 10 KΩ load

Alkaline batteries (Duracell MN1500): 8 Hr. 20 min.

Alkaline batteries (Duracell ProCell PC1500): 8 Hr. 10 min.

NiMH Rechargeable (Energizer NH15): 14 Hr. 39 min.

Test 2:

Constant Stimulation @ 4mA, 500uS pulse width, 1 Hz frequency into a 10 KΩ load

Alkaline batteries (Duracell MN1500): 3 Hr. 5 min.

Alkaline batteries (Duracell ProCell PC1500): 2 Hr. 15 min

NiMH Rechargeable (Energizer NH15): 4 Hr. 35 min

Test 3:

Constant Stimulation @ 1mA, 500uS pulse width, 1 Hz frequency into a 10 KΩ load

Alkaline batteries (Duracell MN1500): 3 Hr. 33 min

Alkaline batteries (Duracell ProCell PC1500): 3 Hr. 6 min

NiMH Rechargeable (Energizer NH15): 5 Hr. 17 min

Test 4:

80% EMG mode with 200Hz, 1mVp-p signal in, Vol:4.

20% Stimulation @ 4mA, 500uS pulse width, 1 Hz frequency into a 10 KΩ load

Alkaline batteries (Duracell MN1500): 7 Hr. 47 min.

Alkaline batteries (Duracell ProCell PC1500):  7 Hr. 35min.

NiMH Rechargeable (Energizer NH15): 9 Hr. 33 min.

Conclusion:

NiMh rechargeable battery use in the Myoguide unit provides considerably more run time compared to disposable alkaline batteries.  This is especially true when the unit heavily used in Stimulation Mode.

NiMH Rechargeable Batteries have the longest Myoguide battery life!

You can visit the Myoguide page for more product details, features, benefits, and specifications if you wish to learn more.

You may purchase your Myoguide EMG/ESTIM BoNT injection guidance system, accessories, and electrodes, directly from the Myoguide Store!  Credit card payments and quotations can be accommodated directly from our website, for your convenience.

Take advantage of current SALE prices on Myoguide and Electrodes before the end of 2022!

Please have a look at our line of excellent Technomed hypodermic needle electrodes and surface electrodes, available on the Myoguide Store . Technomed electrodes have the best performance to price ratio on the market! Save more when you buy using a subscription. Contact us to find out more!

Follow me on LinkedIn