Electric toothbrush - Leave on charger or just when depleted?

[Muse]

This one uses NiCads, an Oral B, bought a few months ago. The instructions say to charge for 16 hours, so I assume it's a trickle charger, i.e. low current, and I believe it's not going to overcharge the cells if the unit is left on the charger. However, if you do that it never runs down. The instructions say to let run down at least once every 6 months to extend the life of the batteries. However, I'm thinking that the batteries might last longer (i.e. they die at a later date) if I only put the unit on the charger when I detect that the batteries are low, then charge for at least 16 hours and then not charge again until the cells are evidently low again. What do you think?

 

[eldorado99]

This one uses NiCads, an Oral B, bought a few months ago. The instructions say to charge for 16 hours, so I assume it's a trickle charger, i.e. low current, and I believe it's not going to overcharge the cells if the unit is left on the charger. However, if you do that it never runs down. The instructions say to let run down at least once every 6 months to extend the life of the batteries. However, I'm thinking that the batteries might last longer (i.e. they die at a later date) if I only put the unit on the charger when I detect that the batteries are low, then charge for at least 16 hours and then not charge again until the cells are evidently low again. What do you think?

Correct.

 

[Muse]

Correct.

Well, maybe one thing to consider is that I have 2 other electric toothbrushes (Sonicare) and I don't use the Oral B all that much, just occasionally, maybe once or twice a week. Might not matter, but the effect is that it doesn't get charged nearly as often as if it were being used daily. The instructions say it will run for about 20 minutes on a charge. That would mean I'd be charging it about every 10 days if I used it daily. I think I'm charging it maybe every 45 days, just guessing. I suppose that's OK.

 

[lxskllr]

I always kept NiCads topped up, and that gave the best battery life. You may want to vary it a bit(every brush/every other brush...), but deep cycling them all the time seems to reduce life.

 

[caddlad]

I only charge my Braun when I notice diminished power. Every 45 days, or so, of daily use.

 

[Suspicious-Teach8788]

NiCads have memory effect. I would run charge down before recharging.

Li-Ions are the ones you shouldn't deep cycle all the time. Only deep cycle once every 6 months or something (your phones, iPods, laptops) to calibrate the battery meter properly.... Maybe 3 months, but not everyday.

 

[lxskllr]

NiCads have memory effect. I would run charge down before recharging.

Memory effect is a bit of a myth. You only run into it under very specific circumstances. You have to discharge the battery to the exact level each time to run into the problem. Example, if you had a voltage sensor start battery charging at exactly 25% of capacity every time, that would create a bottom end at the 25% mark. Normal variances with human use won't cause a memory effect.

 

[boomhower]

I leave mine on the charger. It's just simpler. Longest I would ever travel is a few days so the most run time I would ever need is 30 minutes. I bet the motor dies out before the batteries run down lower than I need. I have the same brush as the OP.

 

[Muse]

NiCads have memory effect. I would run charge down before recharging.

Li-Ions are the ones you shouldn't deep cycle all the time. Only deep cycle once every 6 months or something (your phones, iPods, laptops) to calibrate the battery meter properly.... Maybe 3 months, but not everyday.

I think that NiMH don't benefit from deep cycling, to my knowledge. Just top up when desired. Li-Ions freak me out because they deteriorate faster at certain charge levels.

 

[Muse]

I leave mine on the charger. It's just simpler. Longest I would ever travel is a few days so the most run time I would ever need is 30 minutes. I bet the motor dies out before the batteries run down lower than I need. I have the same brush as the OP.

Motor? You think there's a motor in there?