Working principle of Ni-MH battery  
The active material of the positive electrode is nickel hydroxide and the negative electrode is hydrogen storage alloy. The electro-chemical process of the battery during charging and discharging can be described as follows:  

 The reaction of positive electrode The reaction of negative pole
 ( negative pole) ( positive pole)
Charging Ni(OH)2 +OH?NiOOH+H2O+e Cd(OH)2+2e?Cd+2OH
Over charging 4OH-?2H2O + O2 + 4e 2Cd+O2+2H2O+4e?2Cd(OH)2
Discharging NiOOH+H2O +e?Ni(OH)2+OH Cd+2OH?Cd(OH)2+2e
After discharging Cd(OH)2+2e?Cd+2OH H2+2OH?2H2O +2e
 2H2O+2e?H2+2OH 
  
Overall reaction:  
2Ni ( OH )2 + Cd ( OH )2 ?2 NiOOH + Cd + 2H2O ± Q  

Size	Model No	Nominal	Nominal	Dimension with tube		Stand Charge		Rapid Charge		Weight
		Voltage	Capacity							Approx.
		(V)	(mAh)	Diameter (mm)	Height	Current	Time	Current	Time	(g)
					(mm)	(mA)	(h)	(mA)	(h)
4A	H-38AAAA270	1.2	270	8.7	38	27	27	270	1.2	7
	H-51AAAA400	1.2	400	8.7	51	40	16	400	1.2	9
	H-66AAAA550	1.2	550	8.7	66	55	16	550	1.2	12
3A	H-1/4AAA80	1.2	80	10.5	11.5	8	15	80	1.2	5
	H-1/3AAA120	1.2	120	10.5	14.5	12	15	120	1.2	6
	H-2/3AAA350	1.2	350	10.5	29	35	15	350	1.2	9
	H-3/5AAA450	1.2	450	10.5	35	45	15	450	1.2	10
	H-4/5AAA500	1.2	500	10.5	38	50	15	500	1.2	11
	H-AAA600A/B	1.2	600	10.5	44.5	60	15	600	1.2	12
	H-AAA700A/B	1.2	700	10.5	44.5	70	15	700	1.2	13
	H-AAA800A/B	1.2	800	10.5	44.5	80	15	800	1.2	14
	H-5/3AAA1000	1.2	1000	10.5	66.5	100	15	1000	1.2	18
2A	H-1/2AA550	1.2	550	14.5	24	55	15	550	1.2	13
	H-2/3AA600	1.2	600	14.5	29	60	15	600	1.2	14
	H-2/3AA700	1.2	700	14.5	29	70	15	700	1.2	15
	H-4/5AA1200	1.2	1200	14.5	43	120	15	1200	1.2	23
	H-AA600A/B	1.2	600	14.5	50.5	60	15	600	1.2	18
	H-AA1200A/B/H	1.2	1200	14.5	50.5	120	15	1200	1.2	25
	H-AA1500A/B	1.2	1500	14.5	50.5	150	15	1500	1.2	28
	H-AA1800A/B	1.2	1800	14.5	50.5	180	15	1800	1.2	29
	H-AA2000A/B	1.2	2000	14.5	50.5	200	15	2000	1.2	29
	H-AA2100A/B	1.2	2100	14.5	50.5	210	15	2100	1.2	30
	H-AA2200A/B	1.2	2200	14.5	50.5	220	15	2200	1.2	30
A	H-2/3A1100	1.2	1100	17	28	110	15	1100	1.2	21
	H-4/5A1900	1.2	1900	17	43	190	15	1900	1.2	32
	H-A2300	1.2	2300	17	50	230	15	2300	1.2	35
	H-4/3A3500	1.2	3500	17	67	350	15	3500	1.2	49
N	H-N350	1.2	350	12	30	35	15	350	1.2	10
	H-1/3N120	1.2	120	12	16.5	12	15	120	1.2	6
9V	H-9V 160	9	120	17.5(T)*26.5(W):*48.5(H)		16	15	120	1.2	42
	H-9V 200	9	160	17.5(T)*26.5(W):*48.5(H)		20	15	160	1.2	43
SC	H-4/5SC1800P	1.2	1800	23	34	180	15	1800	1.2	43
	H-SC2500H	1.2	2500	23	43	250	15	2500	1.2	58
	H-SC3000A/B	1.2	3000	23	43	300	15	3000	1.2	60
	H-SC3500A/B	1.2	3500	23	43	350	15	3500	1.2	62
C	H-C1500A/B	1.2	1500	25.8	51	150	15	1500	1.2	42
	H-C4500A/B	1.2	4500	25.8	50	450	15	4500	1.2	82
D	H-D1500A/B	1.2	1500	33	61.8	150	15	1500	1.2	75
	H-D2200A/B	1.2	2200	33	61.8	220	15	2200	1.2	76
Power	H-D5000A/B	1.2	5000	33	61.8	500	15	5000	1.2	125
Battery	H-D9000A/B	1.2	9000	33	60.5	900	15	9000	1.2	170
	H-18670	1.2	3800	18	67	380	15	3800	1.2	60
	H-18670	1.2	4000	18	67	400	15	4000	1.2	66
	H-F12000	1.2	12000	33	90	1200	15	12000	1.2	220
Ni-MH BUTTON CELLS TECHNICAL DATA

Models	Nominal	Nominal	Diameter	Height	ChargeCurrent	Charge Time	Weight
	Voltage	Capacity	(mm)	(mm)	(mA)	(H)	(g)
	(V)	(mAh)
B20H	1.2	20	11.6	3.1	2	14	1.7
B40H	1.2	40	11.6	5.4	4	14	2
B70H	1.2	70	15.2	6.1	7	14	4
B80H	1.2	80	15.2	6.1	8	14	4
B160H	1.2	160	25.6*4.1	5.7	16	14	5.8
B250H	1.2	250	25.2	6.4	25	14	10
B280H	1.2	280	25.2	8.8	28	14	15
B350H	1.2	350	25.2	8.8	35	14	15
B450H	1.2	450	34.1*24.1	5.6	45	14	13
9V-160H	1.2	16	26.7*48.7	43	16	14	43
NIMH PRASMATICAL BATTERY

Size	Model NO	Nominal	Nominal	Dimension with tube		Stand Charge		Rapid Charge		Weight
		Voltage	Capacity							Approx.
		(V)	(mAh)	Diameter	Height	Current	Time	Current	Time	(g)
				(mm)	(mm)	(mA)	(h)	(mA)	(h)
PRASMATIC	29F4-400	1.2	400	16.8×6.1	29.5	40	16	400	1.2	11
	35F5-500	1.2	500	16.8×6.1	35.5	50	16	500	1.2	13
	35JF5-700	1.2	700	16.8×8.3	35.5	70	16	700	1.2	17
	39JF5-850	1.2	850	16.8×8.3	39.5	85	16	850	1.2	19
	48F6-750	1.2	750	16.8×6.1	48.5	75	16	750	1.2	18
	48F6-800	1.2	800	16.8×6.1	48.5	80	16	800	1.2	19
	67F8-1100	1.2	1100	16.8×6.1	67.5	110	16	1100	1.2	23
	67F8-1200	1.2	1200	16.8×6.1	67.5	120	16	1200	1.2	24
	67F8-1300	1.2	1300	16.8×6.1	67.5	130	16	1300	1.2	25
	67F8-1400	1.2	1400	16.8×6.1	67.5	140	16	700	1.2	26