Batteries for SANTI Heating Systems

Batteries for SANTI Heating Systems

In this comprehensive review, we look at batteries for SANTI heating systems, comparing them for functionality, depth, burn times, weight and size to help you decide on which battery to choose for the type of diving you'll be doing and the heating layers you'll be using.
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Updated 10 December 2023

With technological improvements over the past years, we’ve seen several new batteries for SANTI heating systems coming out on the market. By that, we mean batteries that can be used with these heating systems, whether or not manufactured by SANTI. 

From size to weight and power, there are significant differences between these batteries (commonly referred to as Accu) and what they can power up and for how long.

One must also consider the size, weight, and relevant flight restrictions. 

We often get asked questions about batteries for SANTI heating systems, mostly about their burn times, what combinations of heating elements they can support, and whether they can be used with light heads simultaneously.

Without confusing, the power equation is quite simple: All things being equal, the lower the Ah (Amp Hours) of a battery, the less runtime it will have – to the extent that it may not feasibly support a component requiring more power than on offer. Then again, this also means a lower profile and lighter weight if it meets your needs.

Take the smallest and lightest SANTI Diving 6Ah battery, for instance. While it can provide a generous 2 hours of power for SANTI heated gloves, it won’t do much (if anything!) for a SANTI heated undersuit. But you likely already know that…

Looking at batteries for SANTI heating systems at the time of this review (now updated to include the new Santi Blue Power 9Ah Battery), we can list three readily available “types” that can be purchased from DirDirect, given that we’re a leading SANTI and AMMONITE dealer with large stock.

Our batteries for SANTI Heating Systems are:

SANTI 6Ah / 24Ah Batteries

SANTI 9Ah / 14Ah / 28Ah “Blue Power” Batteries

AMMONITE Systems 14Ah / 24Ah & 24Ah-Special “Accu Thermo”

Batteries for diving heating systems

SANTI or AMMONITE batteries?

That question has much to do with what power you need, what element you’ll connect the battery, how long burntime you need (whether for single or multiple dives), what depths you'll be diving to and, of course, your budget.

Firstly though, we need to note that SANTI manufactures its unique brand of SANTI batteries produced explicitly for use on SANTI heating systems. As a diver, you would be purchasing the heating layer components as well as their power supply from the same manufacturer.

The most significant advantage is that in the unlikely event of something going wrong, wherever you are in the world, you’d also be dealing with the same manufacturer able to inspect, test, repair, or replace all the system components, whether in or out of warranty.

With that said, AMMONITE Systems is an equally reliable manufacturer also based in Poland, renowned for its innovative, robust and high-quality lighting systems and batteries. We're always well stocked up with AMMONITE as well as SANTI.

In the UK, we can arrange for both brands to be serviced simultaneously, but it’s worth mentioning and keeping in mind when deciding on a brand or mixing and matching.

Ammonite Systems Dive Light Heads

Which battery can be used with light heads?

While it may be true that you can use almost any power source with a light head, provided the power and connections match that head, real-life usage is different.

This time we’ll start by excluding what batteries are not made to be used on or with a light head, and these are the SANTI 9Ah Blue Power Battery, the  SANTI 14Ah Blue Power Battery, the SANTI 28Ah Blue Power battery that are solely made to be used with heating systems.

This leaves us the SANTI 6Ah & 24Ah batteries and the AMMONITE 14Ah, 24Ah and 24Ah-Special Accu Thermo. (We'll discard the 6Ah battery, given its power).

The SANTI 24Ah battery can be used with compatible e/o cord connection light heads - i.e. the Halcyon Focus 2.0 or the Halcyon Flare EXP as well as the Ammonite heads.

The AMMONITE 14Ah, 24Ah and 24Ah-Special Accu Thermo batteries are great with AMMONITE's own range of light heads that cover all diving conditions. 

The big difference between the listed SANTI and AMMONITE batteries is that the SANTI battery has a single on-off switch on the canister, which controls only one power-out setting. 

This means that even when using a Y-Connector to spread that output to two, every time you switch a light head on and off, your heating system will be switched on and off too – or vice versa.

SANTI Heating system battery switch

On the other hand, the Ammonite 14Ah, 24Ah and 24Ah-Special Accu Thermo batteries have two power outputs from the canister and one switch with three power-on settings, controlling each function individually.

This means you can use either light or heating or both together at any given time during a dive without any conflict.

Ammonite Systems Battery - Thermo Accu

The only restriction is the lower run time when using the two together, which is why some divers will double up with low-profile battery canisters, using one for light and the other for heating.

What's the burntime difference?

There is a significant difference in burntime between heating system batteries depending on the power they supply. 

The 6Ah Accu in our range of batteries for SANTI heating systems is the most affordable, smallest, and lightest battery in the whole range.

Its size and price point make it a popular choice for recreational and technical divers, with enough power for a heated vest for one or two dives, heated gloves for a couple or more dives, or a combination of the two for a single dive.

Even though the SANTI 6Ah battery has enough power to cover most diving conditions and can be doubled up side-by-side on a waist harness due to its low profile, those seeking longer burn times or to power up more than just gloves and a heated vest would benefit from either of the three other SANTI batteries or any one of the AMMONITE Accu Thermo batteries.

With that said, if you can do with just a heated vest or vest+gloves combination, the 6Ah battery is powerful enough to cover your needs.

As you’ll see in the comparison table below, a 14Ah battery can provide 1:20 to 1:30 hours of power for a heated undersuit and around an hour of heating for an undersuit and gloves. In contrast, the 24Ah batteries would support an undersuit for over 2 hours and a combination with gloves for just under 2 hours.

The 14Ah battery, whether SANTI or AMMONITE, gives reasonable burntime and is lighter and less bulky than what we’d call the “Expedition Level” 28Ah battery, covering some serious diving.

At any rate, the 14Ah and 24Ah batteries will provide for many hours of warm diving when used only with the heated vest or vest and glove combination, covering anything from the deepest and longest dives to a whole weekend diving.

Burntimes of batteries for SANTI Heating Systems:

Santi Heating System Batteries Compared

Why the SANTI 28Ah Blue Power battery?

The most powerful heating system battery in our arsenal is the 2023 28Ah SANTI Blue Power Battery, but it’s not for everyone.

For one, it is heavier than the other batteries available. When we say heavy, we mean heavy at 2.8 kilos (6.2 pounds), a whole kilo more than the SANTI or AMMONITE 24Ah batteries, as you’ll have noticed in the table above.

And its overall size is also significant, the combination reminiscent of the older lead acid battery canisters we used to dive with before the much-welcome technological revolution.

With a height of 33.8 cm (13.3 inches) and a diameter of 8.7 cm (3.42 inches), this Blue Power battery is the biggest and most powerful Accu in our line-up of batteries for SANTI heating systems.

The SANTI 28Ah Blue Power battery is an expedition-level battery that will meet the needs of underwater explorers in demanding conditions, whether in caves, mines or deep ocean, with the most extended runtimes available for their warmth.  

What's with the depth rating?

The maximum depth rating of the batteries for SANTI heating systems we provide is 100 metres except for the AMMONITE 14Ah Accu Thermo, rated at 150m, and the 24Ah Special Accu Thermo battery, depth-rated at 200m.

In other words, if you’re regularly diving to depths of 100 metres plus, as some do, the AMMONITE 14Ah and 24Ah Special battery are for you.

This means the rest of the lot will meet the needs and demands of most technical divers who restrict their depth to shallower than 100m.


Overall, regarding batteries for SANTI heating systems, what matters most is what you will power up with them, for how long and at what depths.

The battery which suits you best is determined by several factors such as:

- The type of diving you do; 

- Water temperatures where you dive
- The length of your regular underwater exposure; 
- What your heating layers consist of; 

- How warm or cold you feel on dives;
- Whether you regularly exceed depths of 100m 

As mentioned, most recreational and technical divers in the 40-60m range will find the SANTI 6Ah or 14Ah batteries will do the job. 

They are relatively light with low-profile and avoid the additional weight and bulk of the SANTI 24Ah Battery or the Ammonite 24Ah Thermo Accu.

With this in mind, the 24Ah and 28Ah batteries could be preferred as a long-term option for more demanding underwater exploration, whether in the sea, mines or caves, who need more runtime warmth to cover longer dives, colder environments and extended decompression.

This article on batteries for SANTI heating systems will hopefully help you decide which one is best for you. As always, if you have any further questions, please let us know.

As you’ll know, we have a range of these batteries in store at Underwater Explorers, where you can visit us and handle them before making any purchase. 

And yes, here online, we have a 28-day no-fuss return policy, so long as anything you’ve purchased from us hasn’t been used and is returned as new.

Wishing you all safe and warm dives!

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