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NiMH vs. NiCad Batteries
- Thread starter ohmygato
- Start date
JamesBondaka
Active member
ohmygato said:
I have never really measured it exactly but Im going to say a couple of hours....I use my detector speaker alot and that uses more power. I can say this too....Nimh is faster charging and you dont have to drain them all the way down like ni cads.
Well don't tell my modified Whites holders I cannot use NiMH and use their standard charger. Both NiMH and NiCad are 1.2v batteries. I have been using the Whites standard charger on my modified Whites packs with NiMH batteries for years now. I use Energizer 2300mAh NiMH batteries and the standard Whites charger on overnight; 11.35 volts when I take them off and get a full day's run out of them.
I modify the Whites battery holders (P/N 802-7150) which can be used in the V Series, DFX, XLT, Quantum and Classics. These hold eight 1.2 v AA NiMH (2300mAh rechargeable-available at WalMarts and other stores). With a slight modification I use the standard Whites charger (P/N 509-0022) to charge the rechargeable NiMH batteries. The diode (1N4003) and the plug on the end of the charger can be matched at any electronics shop. The set up gives you the versatility to have rechargeable packs but still use alkaline as backup if necessary.
I modify the Whites battery holders (P/N 802-7150) which can be used in the V Series, DFX, XLT, Quantum and Classics. These hold eight 1.2 v AA NiMH (2300mAh rechargeable-available at WalMarts and other stores). With a slight modification I use the standard Whites charger (P/N 509-0022) to charge the rechargeable NiMH batteries. The diode (1N4003) and the plug on the end of the charger can be matched at any electronics shop. The set up gives you the versatility to have rechargeable packs but still use alkaline as backup if necessary.
Whites uses a thermistor to stop the charging when the correct charge is obtained for the NIMH packs. With this system no diode is used and they don't need ovenight charging. I never used the NICAD charger.
The answer to this question depends on the type of NiCd charger. Depending on the type of NiCd charger you have, the older NiCd charger may undercharge NiMH batteries (most likely), it may overcharge them (less likely), or it may charge NiMH batteries properly (but it's not likely to do so automatically and could take a very long time). Let's take a look at the three cases.
Many of the older NiCd chargers are the simple timed type charger which will charge batteries for a fixed amount of time and then shut off. Unfortunately, since NiCd batteries have a much lower capacity than NiMH batteries, the timer is likely to shut off long before the NiMH batteries are fully charged. This won't harm the batteries, but the NiMH batteries won't be fully charged since the timer will have stopped the charge cycle too soon.
Also common among older NiCd chargers are the so called "overnight" chargers which charge batteries at a low rate as long as the charger is plugged in. This type of charger can fully charge NiMH batteries, but it might take a very long time to do so. It's possible that an old NiCd charger could take as long as 48 hours to fully charge new high capacity NiMH batteries! This type of charger is not likely to damage NiMH batteries unless the batteries are left in the charger for weeks at a time, but it may not be very convenient to use. If you have this type of charger you can get an idea of how long you'll need to charge your batteries by using the calculator found above.
The final possibility is that the older NiCd charger is a rapid charger that will charge NiMH batteries but will not have the necessary circuitry to stop the charge cycle once the NiMH batteries are fully charged. If the NiCd charger is designed to charge batteries in less than two hours it may be this type. In this case the risk is that the older charger will overcharge NiMH batteries. This will be apparent if the batteries get very hot during the charge cycle. (It is normal for NiMH batteries to get warm as they become fully charged, especially in a rapid charger). If the NiMH batteries get too hot to handle and stay that way for more than 20 or 30 minutes, then the NiCd charger is most likely overcharging the NiMH batteries and may shorten their life. You would be most likely to encounter this type of charger if the charger was designed for rapid charging radio control (RC) vehicle batteries. We would recommend that you not use an NiCD rapid charger to charge NiMH batteries.
Glad yours work for you.
The answer to this question depends on the type of NiCd charger. Depending on the type of NiCd charger you have, the older NiCd charger may undercharge NiMH batteries (most likely), it may overcharge them (less likely), or it may charge NiMH batteries properly (but it's not likely to do so automatically and could take a very long time). Let's take a look at the three cases.
Many of the older NiCd chargers are the simple timed type charger which will charge batteries for a fixed amount of time and then shut off. Unfortunately, since NiCd batteries have a much lower capacity than NiMH batteries, the timer is likely to shut off long before the NiMH batteries are fully charged. This won't harm the batteries, but the NiMH batteries won't be fully charged since the timer will have stopped the charge cycle too soon.
Also common among older NiCd chargers are the so called "overnight" chargers which charge batteries at a low rate as long as the charger is plugged in. This type of charger can fully charge NiMH batteries, but it might take a very long time to do so. It's possible that an old NiCd charger could take as long as 48 hours to fully charge new high capacity NiMH batteries! This type of charger is not likely to damage NiMH batteries unless the batteries are left in the charger for weeks at a time, but it may not be very convenient to use. If you have this type of charger you can get an idea of how long you'll need to charge your batteries by using the calculator found above.
The final possibility is that the older NiCd charger is a rapid charger that will charge NiMH batteries but will not have the necessary circuitry to stop the charge cycle once the NiMH batteries are fully charged. If the NiCd charger is designed to charge batteries in less than two hours it may be this type. In this case the risk is that the older charger will overcharge NiMH batteries. This will be apparent if the batteries get very hot during the charge cycle. (It is normal for NiMH batteries to get warm as they become fully charged, especially in a rapid charger). If the NiMH batteries get too hot to handle and stay that way for more than 20 or 30 minutes, then the NiCd charger is most likely overcharging the NiMH batteries and may shorten their life. You would be most likely to encounter this type of charger if the charger was designed for rapid charging radio control (RC) vehicle batteries. We would recommend that you not use an NiCD rapid charger to charge NiMH batteries.
Glad yours work for you.
Larry (IL)
Well-known member
Do what you want as long as you are happy Explorer but my guess is that your system ( NiMH batteries with NiCad charger) is severely undercharging the capacity of the battery. You say you get a full day's hunt from an overnight charge when properly charged, you probably should be getting 4 full days of hunting. The manufactures are pretty smart and if they say to use the right charger for the batteries, I tend to believe them.
I did not suggest using an RC car fast charger; I stated to use the SLOW / OVERNIGHT setting (85mAh) on the Whites charger.
It is true that Whites uses a thermistor in the new NiMH packs and a third center pin in the charger circuit. I tested my charger and pack that came with my V3i. The unit does NOT turn the charger off but shifts from fast charge (high current-green led on) to a trickle charge (low current-no green led) mode when the thermistor senses the batteries are warming up. I use mine to slow charge older packs. If you want to test this---take a Whites battery holders (P/N 802-7150) loaded with NiMH batteries, you must file the tab on the battery holder's lid narrower to fully drop into the charger and make contact with two outer charge pins. Drop it in the charger---since no center contact the green charge light WILL NOT COME ON but by morning the battery pack will be fully charged.
It is true that Whites uses a thermistor in the new NiMH packs and a third center pin in the charger circuit. I tested my charger and pack that came with my V3i. The unit does NOT turn the charger off but shifts from fast charge (high current-green led on) to a trickle charge (low current-no green led) mode when the thermistor senses the batteries are warming up. I use mine to slow charge older packs. If you want to test this---take a Whites battery holders (P/N 802-7150) loaded with NiMH batteries, you must file the tab on the battery holder's lid narrower to fully drop into the charger and make contact with two outer charge pins. Drop it in the charger---since no center contact the green charge light WILL NOT COME ON but by morning the battery pack will be fully charged.