Best 300Ah Lithium Battery (LiFePO4)

Today on Off Grid Power Geek, we’re checking out the best 300Ah Lithium battery UK.

The advent of the Lithium Iron Phosphate (LiFePO4) type of Lithium batteries has changed the whole market. They’re really safe, even safer than lead-acid batteries, deliver far more power and last a lot longer. It’s no surprise, then, that they cost more than lead-acid batteries. But price has really come down a lot in the last year to 18 months.

Our No.1 is the Renogy 300Ah batteries. No.2 is the Eco Worthy 280Ah Lithium battery. No.3 is a left-field option (and cheapest option) – connecting 3 100Ah Kepworth Lithium batteries in parallel! The 4th best option is the LiGen 12V 300Ah Lithium Leisure Battery.

To be clear: all batteries on this list are the modern LiFePO4 (Lithium Iron Phosphate) batteries. We may refer to them as Lithium or Lithium Ion at times, throughout the article.

best overall leisure battery charger

Renogy 300Ah

  • Voltage: 12V
  • Battery Capacity: 300Ah
  • Dimensions: 522L x 240W x 219H mm (20.55 x 9.45 x 8.62 in)
  • Weight: 31.3kg
best value lifepo4 300ah

Eco Worthy Lithium Battery 280Ah

  • Voltage: 12V
  • Battery Capacity: 280Ah
  • Dimensions: 53.3L x 24.1W x 22.4H cm
  • Weight: 29.0kg
lowest cost solution for 300ah battery

Kepworth Lithium Battery 100Ah (x3)

  • Voltage: 12V
  • Battery Capacity: 100Ah
  • Dimensions: Each one: 332 x 176 x 220 mm
  • Weight: 11kg each (so 33kg for 3)
longest guarantee of 300ah battery

LiGen Lithium Leisure Battery 300Ah

  • Voltage: 12V
  • Battery Capacity: 300Ah
  • Dimensions: 520 x 267 x 228mm (including terminals)
  • Weight: 13.1kg

We’ve tested at ton of 100Ah Lithium batteries at this point, and 300Ah Lithium batteries aren’t too different. They just have more Lithium cells and have higher capacity.

We used this data to select the top 300Ah Lithium leisure batteries.

Here are the factors we based our decision on:

  • Power that can be achieved
  • Consistency of power delivery
  • Quality of Lithium cells
  • Build quality of internal components and battery casing
  • Extent of cycle life
  • Longevity

In this review, we’ll also talk about how to maximise the lifespan of your Lithium battery.

Finally, we’ll discuss how to choose which 300Ah LiFePO4 battery option is the best for your specific needs.

Best 300Ah Lithium Leisure Battery Choices

best 300Ah Lithium battery
battery buying guide

As we give information, tips and advice on car batteries and accessories, naturally our content may contain affiliate links, from which we earn, but there’s no extra cost to you. This helps us to continue to make content, which hopefully you enjoy and gain value from.

300Ah Lithium Leisure Battery Reviews

Let’s check out the pros and cons of each 300Ah battery option.

best overall leisure battery charger

Renogy 300Ah LiFePO4 Battery

Pros and who needs this :

It’s Renogy
According to our testing of, at this point, a veritable smorgasbord of LiFePO4 batteries, as well as our analysis of end user feedback to distributors, Renogy have the best quality Lithium Iron Phosphate (LiFePO4) batteries on the market.

They combine well with solar panels, inverters etc.
We found that Renogy batteries work well with various inputs and outputs. Ideally that would be other Renogy products, but as long as the solar panels are good quality, it will work well in combination. That doesn’t mean they combine well with other makes of batteries, no matter whether in parallel or series. No manufacturer recommends combining their batteries with other brands – this is not them being annoying, it’s just not good practice.

Actually pretty good value, for Renogy (who make the highest quality battery)
Still an investment, for sure. But consider that to buy 3 100Ah Renogy batteries will cost well north of £1000, then you have to buy connection equipment (and don’t forget there are some energy losses when you connect several batteries together in parallel!). Given the quality of these batteries, it’s a pretty good price.

Greater safety
Here’s why: the excellent Renogy BMS. The BMSs of most modern LiFePO4 batteries will work well 95% of the time, and won’t actually need to spring into action if you follow the guidelines regarding charging (for example, not trying to charge when it’s too cold). But the Renogy BMS is one that we’d trust most in a pinch. With this one you’re certainly maximising safety and minimising risk of being stuck somewhere without power.

Shelf mode means it’ll keep
It’ll keep, we say. By which we mean, if you’re not going to use it for a while, you can activate shelf mode. That drops self-discharge down from low (as is the case with modern LiFePO4 batteries anyway) to really, wonderfully low. It really will keep.

Update March 2024: new version of this Renogy 300Ah Lithium ion battery – connectivity is now excellent
The previous version allowed no series connections at all. But now you can join 4 in series and 4 in parallel, giving you a mammoth 61.44kWh battery system

Cons and why this model is not for you:

No Bluetooth connection for this model
Why, Renogy? Why? For this price, we’d love to have access and ability to use an App to check and track the operation ability, charge status and health of the battery on the App.

Where can you get it?

Here’s where to check this Renogy battery out, on Amazon.

best value lifepo4 300ah

Eco Worthy 280Ah Battery

Pros and who needs this :

Good cyclic durability
The Eco Worthy Lithium battery performed very well in our tests of cyclic durability. You can discharge this battery right down to 90-95% and maybe even a little more. And it won’t be harmed. That’s a testament to the quality of the Lithium cells and the inner components. That said, if you really want to maximise lifespan, we’d recommend not discharging completely (to 100%) too often, taking it to 80-90% can mean it’ll last an extra few years.

Fast charging
A full charge in under 2 hours, they said. And sure enough, it did just that, achieving 100% charge in less than 2 hours. The LiGen battery is also fast charging, taking just over 2 hours, but the Eco Worthy LiFePO4 took the win on this metric.

Likely to last a really long time
It’s speculative, of course, but given Eco Worthy quality and the excellent cyclic durability we observed, we’d certainly be expecting a minimum of 10 years and likely to be beyond even that. You’d probably take 10 years, no? By the way, Eco Worthy are saying even 20 years is possible (presumably as a maximum). Now, we’ll say that’s *extremely* speculative, but if you even get close…

Cons and why this model is not for you:

Provides around 250Wh less than the Renogy battery
The inevitable consequence of including a 280Ah LiFePO4 battery in an article about 300Ah batteries: it obviously provides less power. The power is 3584Wh, compared to Renogy’s 3840Wh, a difference of 256Wh. Only you can decide if you want the extra buffer of that additional power.

Slightly less established brand, compared to Renogy
Renogy are more well known, with a very good reputation for their solar products, with good reputation for their quality and longevity. Eco Worthy aren’t quite so established, but their quality is very good all the same.

Where can you get it?

Check out the lowest cost place to get it, right here.

lowest cost solution for 300ah battery

Kepworth Lithium Ion Battery 100Ah

Pros and who needs this Lithium leisure battery:

It’s the full package – high energy density Lithium cells and high quality BMS
We’ve tested Kepworth batteries a lot, and gotten plenty of feedback in the market about them. Their power consistency is excellent, and the BMS is one of the best on the market. We rate it as perhaps the safest and most reliable LiFePO4 battery on the market.

Even more combination options than Renogy and Eco Worthy
You can connect up to 5 batteries in series (that’d be a 51.2V system) and an unlimited amount in parallel. So no matter the size of battery bank you want, you can keep connecting more Kepworth batteries with no problems.

It works out cheaper
Even buying three of these batteries works out a lot cheaper than buying a single Renogy, Eco Worthy or Ligen 300Ah Lithium battery. Why?? It comes down to simple competition. The 100Ah Lithium leisure battery market is a dogfight, and prices have come down a lot in 2022. The 300Ah is not so competitive, and so prices remain relatively high.

Cons and why this model is not for you:

It’ll take up more space
Having 3 batteries connected in parallel is inevitably going to take up more space than one single 300Ah battery. If space is a concern, you’re certainly better off going for one of the other 300Ah battery options on this list.

The 3 x 100Ah Kepworth battery bank will be heavier
Again, as you may have expected, this will be heavier than having a single battery. But at a combined 33kg, it’s not that much more than the 29.0kg of the Eco Worthy battery, for example.

It’s a bit more hassle and less tidy to have a battery bank
Connecting the batteries in parallel isn’t that difficult at all, it won’t take long. But it’s bit of added inconvenience if you ever need to move them, and perhaps need to disconnect them and reconnect them. And with the wires going between them, this could get in the way and be troublesome, depending in where you’re going to be keeping the batteries..

Where can you get it?

Your cheapest option by far to get it is on Amazon, here.

longest guarantee of 300ah battery

LiGen 300Ah Lithium Leisure Battery

Pros and who needs this :

It’s super lightweight, a third the weight of a lead-acid battery
That makes it far more convenient to install, and to move it around if you ever need to do that. If you’re buying the Lithium battery for a campervan or motorhome, then the weight saving can save you petrol costs. It’s a small amount that adds up to quite a lot over a period of many years.

Long-lasting and with consistent power delivery
With the LiGen 300Ah Lithium battery, you’re very likely to get at least 10 years lifespan and perhaps more. In our testing, it also maintained power very well throughout usage, without dips or losses of power. It kept this high voltage right up until the battery was almost completely used up. That’s vastly different to lead-acid batteries, which drop fairly sharply in voltage, and can experience major dips as charge gets low.

Extremely safe, excellent quality BMS
A Lithium battery is only as good and as safe as its BMS, it’s the brains of the operation. In the case of this LiGen battery, we found the BMS to be of high quality. It monitored the cells for over-voltage, made sure the operating temperature was safe, checked for over-discharge and over-current. It performed each of these tasks to a satisfactory level. And therefore, we conclude that this is as safe a battery as there is on the market.

High power capabilities
Continuous current output of 200A is the most we’ve seen in a battery of this size. We were impressed by the power offered by the LiGen battery in all states of charge, and it coped well with powering devices that need a high current to operate. So it’ll provide a huge power of 2560W continuously. And the absolute Peak current of 400A for 10 seconds is greatly superior to our No.2 model which has Peak current of 300A for 3 seconds. Overall, LiGen are one of highest quality high-powered Lithium battery makers in the world; they also topped our review of the best 24V 200Ah Lithium batteries.

It has the most combination options (to form a battery bank) we’ve seen
Allowing for 4 batteries to be connected in parallel AND 4 batteries to be connected in series is highly impressive. Again, it’s something we’ve not seen before in a battery of this size. It speaks for the build quality of these batteries and the sophistication of the BMS that you can combine these batteries for larger power banks, according to your needs; be it higher voltage (connected in series) or higher Amperage (connected in parallel).

Cons and why this model is not for you:

There’s no shelf mode
Some Lithium batteries have a shelf mode, which acts effectively as an off switch. It means that when the battery is not being used, you can change to shelf mode, and the self-discharge drops to a minuscule level. This LiGen battery has very low self-discharge by battery standards, at 3.5% per month. A battery with shelf mode can achieve that level of self-discharge across 6 months or even a year. Admittedly, we’re yet to see a 300Ah battery on the market which has shelf mode, so far we’ve only seen 100Ah Lithium batteries with this mode.

It’s not cheap
It’s certainly not cheap. But you do have to consider that 300Ah is a lot of power. And it’s very realistic to get 10-15 years of usage from a Lithium battery of this quality. Bear that in mind when you consider if the investment is worth it.

Where can you get it?

Here’s the lowest priced seller, check it out.

How to choose the right 300Ah Lithium battery for you?

Here’s how to make your decision.

A single 300Ah battery or 3 x 100Ah battery bank?

One of the key decisions is do you get a single battery or a battery bank.

A single 300Ah Lithium battery has the following advantages:

  • Takes up less space (potentially a lot less space)
  • Easier to install and move around
  • Less wiring causing untidiness and hassle to deal with
  • Lighter (though perhaps not a huge difference)

A 3 x 100Ah battery bank has the following advantages:

  • At current price levels, it can work out much cheaper
  • Safety/backup. As they’re wired in parallel, if one battery fails, the other 2 will still provide power. Lithium batteries are very reliable, but it’s still a good thing to know.

If you choose the 100Ah option, here’s a full review of the Kepworth LiFePO4 battery.

LiGen vs. Beyond Batteries

If you’ve decided on a single 300Ah battery, those are the 2 best batteries on the market of that size.

The LiGen provides more power, and we deem its BMS to be one of the market leaders. LiGen are a highly respected maker as well. The Beyond Batteries Lithium battery is really solid in all respects, with good BMS quality and Lithium cells quality as well. Its power delivery isn’t quite as good as the LiGen battery.

Should I even get a Lithium battery?

Frankly, the LiFePO4 Lithium (the type of Lithium used in each battery on this list) is better than lead-acid batteries in every single way. It’s more reliable, delivers more power, can be discharged to 80-90% at least (compared to 50% for lead-acid batteries), lasts for 2 to 3 times longer (how long do lead-acid leisure batteries last), and is even safer.

Here’s the best analysis of what Lithium leisure batteries offer.

Thinking of another size of Lithium battery?

Here are the best 100Ah 24V Lithium batteries in the UK.

300Ah Lithium Battery Summary

That’s it for our analysis of the best 300Ah Lithium leisure batteries.

We checked out the best options on the market, and we detailed our testing and feedback to come to our decision. The No.1 is the Renogy 300Ah battery At No.2 is the Eco Worthy 280Ah battery. And at no.3 is the option of connecting 3 x 100Ah Kepworth Lithium batteries in parallel. At no.4 is the LiGen 300Ah Lithium battery,

We discussed the merits of each option, giving you the pros and cons in terms of operation, longevity and power delivery.

Best of luck with your decision!