But be aware that NiMH may have different slightly different charge characteristics then a NiCad and may be less tolerant of trickle charge current.NiMH would also do the job and are likely to have more power for their size and have the added bonus of not having the NiCad "memory effect"
They will work perfectly.hi
My spouse has an elec broom that needs batteries and all i can find are ni-cd 1.2v 1600mah and the ones that came with it are ni-cd 1.2v 1700mah, is there any reason the 1600mah shouldn't work and charge ok ?
Probably not correct: NI-MH will not tolerate the sustained charge current most chargers send into the Ni-CDs. It will kill them over time.so i can replace the ni-cd 1.2v 1700mah with NiMH 1.2v 1700mah and not have to change the fuse or the charging system at all ?
I guarantee that type has a lot of continuous charge current. Not for NI-MH.thank you all
but until i'm more comfortable with the charging system of the broom quick and dirty fix is to just use the ni-cd batteries.
although in the future changing it to NI-MH, i'm going to check into.
the charging board is three diodes one resistor and an led and an 12v wall-wart plugs into 110v and then into the broom.
i'm going to draw out the circuit maybe i will understand it more.
If that's all the circuitry the charger has then it apparently just charges the batteries with a continuous charge current and doesn't drop to a trickle charge after the batteries are charged. NiCds can tolerate that (with reduced life) but NiMH cells generally can't............................
the charging board is three diodes one resistor and an led and an 12v wall-wart plugs into 110v and then into the broom.
i'm going to draw out the circuit maybe i will understand it more.
Could you please explain your reasoning behind thinking it's using a constant current source? What are you thinking the circuit looks like?If that's all the circuitry the charger has then it apparently just charges the batteries with a continuous charge current and doesn't drop to a trickle charge after the batteries are charged. NiCds can tolerate that (with reduced life) but NiMH cells generally can't.
Energizer and a Japanese Ni-MH battery manufacturer also recommend that a trickle charge should not exceed C/40.When we worked with Gates, their rule was the sustained charge current for NI-MH should not exceed c/40. Most Ni-Cds easily tolerate sustained charge of C/5.
Energizer (American) and a Japanese Ni-MH battery manufacturer also recommend that a trickle charge should not exceed C/40.When we worked with Gates, their rule was the sustained charge current for NI-MH should not exceed c/40. Most Ni-Cds easily tolerate sustained charge of C/5.
A sub-C battery cell is physically shorter than a normal C cell so it won't fit. Also it has less "stuff" inside so it won't have the higher capacity.i ordered the wrong ones.
If the batteries have the same Ah capacity and they will fit, then they should work.ok i got the batteries, hum i ordered the wrong ones i was more intent on getting the same 1600mah than the correct size of the battery.
so i needed c's and i ordered sc's (sub c's) will they still work in moms broom.
With such few parts, all it can have is a rectifier to convert the AC to DC and a resistor to determine the (fixed) charge rate. There apparently is no circuitry to reduce the charge rate after the battery is charged.Could you please explain your reasoning behind thinking it's using a constant current source? What are you thinking the circuit looks like?