The short answer: the ALPHA 3 MINI packs 314Ah into a case about 40% smaller than the full-size ALPHA 3, so it is the one to buy when space is the problem. The full-size ALPHA 3 is the one to buy when current is the problem: it is rated for 300A continuous against the MINI's 200A. The ALPHA 6 MINI is the answer when you want more than 400Ah in one box. It holds 460Ah and, by Rich Solar's figures, takes 42% less space than two ALPHA 2 200Ah batteries.
Side by side
| ALPHA 3 MINI | ALPHA 3 | ALPHA 3 PRO | ALPHA 6 MINI | |
|---|---|---|---|---|
| Capacity | 12V 314Ah | 12V 300Ah | 12V 314Ah | 12V 460Ah |
| Rated energy | 4,019Wh | 3,840Wh | 4,019Wh | 5,888Wh |
| Size (L x W x H) | 15.1 x 7.6 x 9.9 in | 20.6 x 10.6 x 8.7 in | 20.5 x 10.6 x 8.7 in | 20.6 x 9.4 x 8.6 in |
| Weight | 61.7 lb | 71.7 lb | 71.7 lb | 88.2 lb |
| Max continuous current | 200A | 300A | 200A | 200A |
| Cycle rating | 5,000+ | 5,000+ | 8,000+ | 5,000+ |
| Heater / Bluetooth | Yes (100W) / Yes | Yes / Yes | Yes / Yes | Yes (100W) / Yes |
| Ingress protection | IP65 | IP65 | IP65 | IP65 |
| Warranty | 5 years | 5 years | 10 years | 5 years |
All specifications are Rich Solar's, from the product pages we list. All four charge between 32 and 131°F, warm themselves with an internal heater for cold-weather charging, and can be paralleled up to four units.
Space: where the MINI earns its name
Multiply out the dimensions and the ALPHA 3 MINI is about 1,136 cubic inches against about 1,900 for the ALPHA 3 and ALPHA 3 PRO, which is 40% smaller and in line with Rich Solar's own claim. Its footprint is about 115 square inches against about 218 for the full-size battery, so it can stand in a space roughly half the floor area. The trade is height: the MINI is 9.9 in tall against 8.7 in. Measure the height under your bench or step before you order.
The ALPHA 6 MINI is the same length as a full-size ALPHA 3 but narrower, at 9.4 in wide against 10.6 in, and it holds 460Ah instead of 300Ah. Against two ALPHA 2 200Ah batteries side by side (each 20.9 x 8.1 x 8.5 in), it works out to about 42% less volume, matching Rich Solar's figure, and you lose the interconnect cables and a second set of terminals.
Weight: the MINIs carry more energy per pound
Dividing rated energy by weight, the ALPHA 3 MINI carries about 65Wh per pound and the ALPHA 6 MINI about 67Wh per pound. The full-size ALPHA 3 carries about 54Wh per pound and an ALPHA 2 about 48Wh per pound. On a trailer close to its cargo limit, the MINI saves 10 lb over the ALPHA 3 while holding more energy.
Current: where the full-size ALPHA 3 wins
This is the number to check if you run a big inverter. A rough rule for a 12V inverter is AC watts ÷ 12 ÷ 0.9. A 2,000W inverter at full load pulls about 185A, and a 3,000W inverter about 280A.
- The ALPHA 3 MINI, ALPHA 3 PRO and ALPHA 6 MINI are rated for 200A continuous: enough for a 2,000W inverter on its own.
- The ALPHA 3 is rated for 300A continuous: enough for a 3,000W inverter on its own.
If you want the MINI's size and a 3,000W inverter, plan on two batteries in parallel, which share the current. Our NOVA inverter guide covers matching inverter to battery.
How long will each one last?
We plan on 90% of rated energy as usable. That gives about 3,600Wh for the 314Ah MINI and PRO, about 3,450Wh for the ALPHA 3, and about 5,300Wh for the ALPHA 6 MINI. A boondocker using 1,500Wh a day, a common figure for a compressor fridge, Starlink, a laptop, lights and a furnace fan, gets a little over two days from a 314Ah battery and about three and a half days from the ALPHA 6 MINI before solar or driving puts anything back. Your number will differ; measure it with a battery monitor such as Rich Solar's 500A monitor with shunt.
Which one should you buy?
ALPHA 3 MINI
Van builds, truck campers and trailers where the battery has to go under a seat or into an existing compartment. It gives you the full 314Ah in the smallest 314Ah case of the Rich Solar batteries we carry, with the heater and Bluetooth.
ALPHA 3
Rigs with the room for a full-size case that want one battery to run a 3,000W inverter. Its 300A rating ties with the ALPHA 3 LITE as the highest of any 12V ALPHA we stock.
ALPHA 3 PRO
Full-timers who cycle the battery daily and want the 8,000+ cycle rating and 10-year warranty. It is the same 314Ah as the MINI in a full-size case.
ALPHA 6 MINI
Anyone who would otherwise buy two 200Ah batteries. One 460Ah box saves space, cabling and a parallel connection. At 88.2 lb, plan for two people to lift it.
FAQ
Is the ALPHA 3 MINI the same battery as the ALPHA 3 PRO, just smaller?
Both are 314Ah and 4,019Wh with a 200A rating, but Rich Solar rates the MINI for 5,000+ cycles with a 5-year warranty and the PRO for 8,000+ cycles with a 10-year warranty. The PRO is also UL 1973 certified; the MINI lists UN38.3.
Can I parallel MINI batteries?
Yes, up to four units, per Rich Solar. Use identical batteries of the same age, and fuse the bank as a whole.
Will a MINI charge in freezing weather?
Yes. Both MINIs have a 100W internal heater, so they can warm themselves to charge. Charging itself happens between 32 and 131°F.
Where do they ship from?
From our warehouse in Upland, California, to the lower 48 states only. Compare the whole lineup in ALPHA LITE vs ALPHA vs PRO or browse the Rich Solar collection.