ExpertPower EXP12330 12V 33Ah Deep Cycle AGM Battery

ExpertPower EXP12330 is a very popular BCI Group U1 battery, featuring a nominal voltage of 12 volts and a nominal capacity of 34.4 Ah and 10h capacity of 33 Ah - hence the label EXP12330.

ExpertPower EXP12330 is a maintenance-free, spill-proof Absorbent Glass Mat (AGM), Sealed Lead-Acid (SLA) battery, commonly used in standby and float applications and even as starting battery for smaller gas engines.

Published: June 23, 2020.

ExpertPower EXP12330 Features and Specifications

ExpertPower EXP12330 AGM battery comes in two main versions, differing only in terminal type:

- T3 Terminal Posts: M5 Nut&Bolt,

- B2 Terminal Posts: M6 Bolt.

Note: Unless otherwise stated, all information in this article is given for the ExpertPower EXP12330 with B2 terminal posts (M6 bolt) - although differences among these two models (except terminals) are practically negligible.

Physical dimensions of the ExpertPower EXP12330 are (L x W x H) 7.72 x 5.16 x 6.34/7.09 inches (~19.6 x 13.1 x 16.1/18 cm) and it weighs 23.81 pounds (~10.8 kg).

ExpertPower EXP12330 is a very popular BCI Group U1 battery, featuring a rather balanced design and offering very good performances at an acceptable price.

ExpertPower EXP12330 is a general-purpose valve-regulated AGM battery, primarily intended for standby and deep discharge applications.

As a standby battery, it has designed float life of up to 5 years, which is excellent for the battery in its class.

Note: float life depends very much on the battery temperature and the battery charger/maintainer during the standby period.

As a deep discharge battery, the capacity of the ExpertPower EXP12330 battery depends on the discharge current:

- 20 hours (1.72 Amps, down to 10.8 volts): 34.4 Ah,

- 10 hours (3.30 Amps, down to 10.8 volts): 33.0 Ah,

- 5 hours (6.30 Amps, down to 10.5 volts): 31.5 Ah,

- 1 hour (21.09 Amps, down to 10.5 volts): 21.09 Ah.

Note: 1h capacity of the ExpertPower EXP12330 is ~61.5% of its 20h capacity, which is good for general purpose battery (it usually ranges between 55 and 65% for general-purpose batteries and up to 70-73% for high-end, dual-purpose batteries).

Also, the number of charging/discharging cycles depends on the Depth of Discharge percentage (DoD%):

- when the battery is being discharged down to 100% DoD, it can withstand ~190 cycles with the capacity loss down to 80% of nominal capacity and ~210 cycles with the capacity loss down to 60% of nominal capacity,

- when the battery is being discharged down to 50% DoD, it can withstand ~380 cycles with the capacity loss down to 80% of nominal capacity and ~460 cycles with the capacity loss down to 60% of nominal capacity,

- when the battery is being discharged down to 30% DoD, it can withstand ~850 cycles with the capacity loss down to 80% of nominal capacity and ~1100 cycles with the capacity loss down to 60% of nominal capacity.

Of course, the number of cycles depends on the battery temperature and charging/discharging currents, quality of the battery charger, and similar.

Maximum charging voltage depends on the battery use, and should be (at 77°F, 25°C):

- Cycle use: 14.4 - 14.7 volts (-30 mV/°C),

- Float use: 13.5 - 13.8 volts (-20 mV/°C).

The maximum allowed charging current is 8.25 Amps. In order to prolong the operating life of the battery, it is highly recommended to charge it with a current that is in the 4-6 Amps range - such current can fully recharge the ExpertPower EXP12330 battery discharged down to 50% DoD in less than 4 hours.

One of the very important features of ExpertPower EXP12330 AGM battery is a low self-discharge rate, which depends on the battery temperature:

- at 104°F (40°C): battery will self-discharge down to 80% in slightly longer than 1 month and down to 60% after slightly longer than 3 months,

- at 86°F (30°C): battery will self-discharge down to 80% in slightly less than 2 months and down to 60% after approximately 6 months,

- at 77°F (25°C): battery will self-discharge down to 80% in slightly less than 3 months and down to 60% after approximately 10 months,

- at 41°F (5°C): battery will self-discharge down to 80% in approximately 10 months.

So, when storing the battery, it is very important to keep it in a cool place, preferably above the freezing temperature. Also, attaching an intelligent AGM battery charger/maintainer can prolong the battery's shelf life for a very long time.

ExpertPower EXP12330 AGM Battery Discharge Charts

The following chart shows ExpertPower EXP12330 battery constant current discharge rates (at 77°F, 25°C - given in Amps):

Cell End Voltage	Battery End Voltage	5 min	10 min	15 min	30 min	1 hour	2 hours	3 hours	4 hours	5 hours	6 hours	10 hours	20 hours
1.85 V	11.1 V	115.09	67.94	53.40	34.81	20.32	11.74	9.02	7.41	6.07	4.95	3.24	1.69
1.80 V	10.8 V	117.29	69.24	54.42	35.47	20.70	11.97	9.19	7.55	6.18	5.04	3.30	1.72
1.75 V	10.5 V	119.49	70.54	55.44	36.14	21.09	12.19	9.36	7.69	6.30	5.14	3.37	1.75
1.70 V	10.2 V	130.25	74.77	58.77	37.58	21.46	12.41	9.53	7.82	6.41	5.23	3.43	1.78
1.67 V	10.02 V	143.39	81.12	63.76	39.68	21.69	12.54	9.63	7.91	6.48	5.28	3.46	1.80

New, fully charged ExpertPower EXP12330 is able to provide (at 77°F, 25°C) 143.39 Amps for 5 minutes with the battery's end voltage of 10.02 volts (1.67 volts per cell).

After discharging the battery, it is highly recommended to charge it as soon as possible.

ExpertPower EXP12330 features ~8.5 mΩ internal resistance, and although it is not intended as a starting battery, it can be used as a cranking battery for small internal combustion engines not requiring more than ~140-150 Amps - power generators, lawn tractors, small boat engines, etc.

The following chart shows ExpertPower EXP12330 battery constant power discharge rates (at 77°F, 25°C - given in Watts):

Cell End Voltage	Battery End Voltage	5 min	10 min	15 min	30 min	1 hour	2 hours	3 hours	4 hours	5 hours	6 hours	10 hours	20 hours
1.85 V	11.1 V	1346.58	794.94	624.78	407.28	237.66	137.4	105.48	86.64	70.98	57.9	37.92	19.74
1.80 V	10.8 V	1372.32	810.12	636.72	415.02	242.22	140.04	107.52	88.32	72.36	58.98	38.64	20.1
1.75 V	10.5 V	1398.06	825.3	648.66	422.82	246.78	142.62	109.56	89.94	73.68	60.12	39.36	20.46
1.70 V	10.2 V	1523.88	874.8	687.54	439.68	251.1	145.14	111.48	91.56	75	61.14	40.08	20.82
1.67 V	10.02 V	1677.66	949.08	745.92	464.28	253.8	146.7	112.68	92.52	75.84	61.8	40.5	21.06

New, fully charged ExpertPower EXP12330 is able to provide (at 77°F, 25°C), for example, 246.78 watts for 60 minutes with the battery's end voltage of 10.5 volts (1.75 volts per cell).

As the battery gets older, its discharging features degrade - typically for all similar AGM SLA batteries.

ExpertPower EXP12330 as a Wheelchair Battery

ExpertPower EXP12330 is commonly used as a wheelchair battery - a pair of ExpertPower EXP12330 may power 2x250 watts motors for up to 1 hour continuously.

Since wheelchairs are rarely used at full power for such long periods, the runtime of the pair of ExpertPower EXP12330 may be much longer.

Smaller wheelchairs are usually powered by a single battery - one ExpertPower EXP12330 may power 2x150 watts wheelchair for up to 40 minutes, at full power, with some energy left in the battery in order to prolong its operating life.

ExpertPower EXP12330 vs Other BCI Group U1 Batteries

Because of all its features and affordable price, ExpertPower EXP12330 is a very popular BCI Group U1 battery.

The following comparison chart lists some of the most popular BCI Group U1 batteries and their features:

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Long Story Short: ExpertPower EXP12330 offers very good performances at an affordable price and is commonly used as a general-purpose 12V 33Ah battery in standby/float and cycle applications in medical and security applications, in electric vehicles and scooters, as wheelchair battery and similar.

If You are looking for a new BCI Battery U1 Group battery, consider this model.

For more reviews and recommendations, feel free to check ExpertPower EXP12330 Amazon link.