100Ah lithium battery: same capacity, three very different boxes
We research products from makers' specs, manuals and safety agencies; we do not run hands-on tests. Links to Amazon may earn us a commission at no cost to you. How this works.
Quick answer
A 12 V 100Ah LiFePO4 battery stores about 1,280 Wh (12.8 V times 100 Ah), whichever brand you buy. What changes is the box around it. Redodo's Ultra-Mini fits that energy in a Group 22NF case weighing 19.8 lb. Power Queen's Group 24 Smart is larger at 22.16 lb and lists 280 A for 5 seconds. Redodo's Self-Heating model is the biggest at 13 in long and 23.32 lb, but it warms itself so it can charge in the cold. At the 20 A charge current all three recommend, a full charge takes about 5 hours.
What 100 Ah means in usable energy
All three batteries here are 12 V class lithium iron phosphate (LiFePO4) packs with a 12.8 V nominal voltage. Multiply voltage by capacity to get stored energy: 12.8 V x 100 Ah = 1,280 Wh. The makers also list the same ceiling on output: 100 A continuous, or 100 x 12.8 = 1,280 W.
Redodo gives a real-world example: one full charge runs a 30 W fish finder for about 42 hours. That checks out, since 1,280 Wh divided by 30 W is 42.7 hours. A 100 W load would run for about 12.8 hours by the same math, before any losses from an inverter or wiring, so plan on less in practice.
Same energy, three case sizes
| Battery | Case | Size (L x W x H) | Weight |
|---|---|---|---|
| Redodo 12V 100Ah Ultra-Mini Bluetooth | Group 22NF | 9.02 x 5.43 x 8.19 in | 19.8 lb |
| Power Queen 12V 100Ah Group 24 Smart | BCI Group 24 | 10.24 x 6.61 x 8.27 in | 22.16 lb |
| Redodo 12V 100Ah Self-Heating | Not stated as a group | 13 x 6.77 x 8.43 in | 23.32 lb |
By box volume the Ultra-Mini takes about 401 cubic inches, the Group 24 about 560 and the self-heating model about 742, so the Group 24 box is roughly 1.4 times the Ultra-Mini's for the same 1,280 Wh. The weight gap is smaller: 3.52 lb between lightest and heaviest. Measure your battery tray or compartment before choosing; Power Queen says its Group 24 also suits trays built for Group 24, 27 and 31 packs.
Charging time and settings
All three list a recommended charge current of 20 A (0.2C). At that rate, 100 Ah divided by 20 A is about 5 hours from empty, which is the figure Power Queen and Redodo both give. Settings to match on your charger, solar controller or DC to DC charger:
- Charge voltage: Redodo lists 14.4 V plus or minus 0.2 V for both its models. Power Queen's spec table says the same, while its product description recommends 14.6 V, the top of that range.
- Charger type: Redodo notes that equipment used with old lead-acid batteries must support the LiFePO4 charging mode before you switch.
- Maximum current: each lists 100 A continuous charge and discharge, so a 20 A charger is well within limits.
Cold weather: protection versus heating
Each maker blocks charging below freezing through the battery management system (BMS), but they handle the cold differently:
- Redodo Ultra-Mini and Power Queen Group 24: charging stops below 32°F (0°C) and resumes above 41°F (5°C); discharging stops below -4°F (-20°C). These batteries protect themselves, but they will not take a charge in a freezing space until they warm up.
- Redodo Self-Heating: 100 W of heating pads switch on below 32°F and off at 41°F, after which charging resumes. That is why its spec table lists a charging range starting at -4°F while its description says charging pauses below 32°F: the heater warms the cells first.
If your battery lives in an unheated shed, trailer or boat over winter and you need to recharge there, the heated model is the one designed for it.
Monitoring, expansion and what not to use it for
- Bluetooth: both Bluetooth models show state of charge and voltage in an app; Redodo adds cycles and temperature, Power Queen adds current and power.
- Building a bank: Redodo and Power Queen allow up to 16 batteries (4 in series by 4 in parallel), or 16 x 1.28 kWh = 20.48 kWh. Power Queen warns its Smart Group 24 is incompatible with its Premium and Mini batteries, so do not mix models in one bank.
- Not a starter battery: Power Queen and Redodo both say these are not for engine starting, golf carts or high-power loads such as water pumps, jacks, lifts, pool vacuums or mowers.
- Cycle claims: both brands list 4,000 or more cycles at 100% depth of discharge; Power Queen adds 6,000+ at 80% and 15,000+ at 60%. Redodo's Ultra-Mini and the Power Queen list a 5-year warranty.
What to look for when you buy
Smallest case example: Redodo 12V 100Ah Ultra-Mini Bluetooth
Best for: Tight compartments, kayaks and setups where one person lifts the battery
Redodo lists 1,280 Wh in a Group 22NF case (9.02 x 5.43 x 8.19 in) at 19.8 lb, Bluetooth monitoring, IP65, a 100A BMS and low-temperature charge protection.
Watch out: No heater: it will not charge below 32°F until it warms above 41°F.
See options on Amazon (opens Amazon in a new tab)Standard Group 24 example: Power Queen 12V 100Ah Group 24 Smart
Best for: Replacing a Group 24 lead-acid battery in an RV or boat tray
Power Queen lists a BCI Group 24 case at 22.16 lb, Bluetooth with current and power readings, 100 A continuous, 280 A for 5 seconds, IP65 and about 5 hours to full at 20 A.
Watch out: Do not mix it with Power Queen's Premium or Mini batteries in one bank; not for starting engines.
See options on Amazon (opens Amazon in a new tab)Cold-storage example: Redodo 12V 100Ah Self-Heating
Best for: Batteries that must recharge in unheated sheds, trailers or boats
Redodo lists 100 W heating pads that run below 32°F and stop at 41°F so charging can resume, plus a 100A BMS, 500 A surge and IP65.
Watch out: Largest and heaviest of the three at 13 x 6.77 x 8.43 in and 23.32 lb; no Bluetooth is listed on its product page.
See options on Amazon (opens Amazon in a new tab)Questions people ask
- How many watt-hours is a 100Ah lithium battery?
- About 1,280 Wh for a 12.8 V LiFePO4 battery: 12.8 V times 100 Ah.
- How long does a 100Ah lithium battery take to charge?
- About 5 hours from empty at the 20 A current these makers recommend (100 Ah divided by 20 A). A smaller charger takes proportionally longer.
- How long will a 100Ah lithium battery last?
- Divide 1,280 Wh by the load in watts. Redodo cites about 42 hours on a 30 W fish finder; expect less through an inverter.
- Can I charge a 100Ah lithium battery below freezing?
- Not without a heater. Standard models stop charging below 32°F; Redodo's self-heating model warms its cells to 41°F first, then charges.