Under Bonnet Lithium Batteries

**DiscoDB** · 3rd December 2025, 03:49 PM

Starting to see more 12v lithium batteries which are claimed to be suitable for under bonnet and now even cranking duty use.

One is the Invicta Hybrid Starter, which comes with an 80ah nominal capacity, 800amp max discharge current, and 1400CCA. Claims to be good for 100% DoD 2000 cycle life, which would translate to a long life.

SSB also have lithium cranking batteries warranted for under bonnet use. And Optima have a smaller OrangeTop QH6 lithium cranking battery which is similar size to the Yellowtop D34.

Whilst we also know iTech has the under bonnet secondary battery which Tombie I believe is using. I believe the iTech range is growing as well.

They all look to be using lithium cells developed for EV or Hybrid applications.

Interested to hear if anyone has experience with any of these “under bonnet” use lithium batteries.

**PhilipA** · 3rd December 2025, 04:22 PM

Alloffroad has experience! DCS Lithium LiFePo4 Under Bonnet Update: I went back to Lead Acid (under bonnet) 2023
This is pretty famous .
Regards PhilipA

**DiscoDB** · 3rd December 2025, 04:50 PM

For balance good to also publish the DCS statement and leave it at that.

DCS Statement Regarding Outcome of Court Decision

So let’s not go down the potential defamation path.

**p38arover** · 4th December 2025, 09:01 AM

Originally Posted by DiscoDB

So let’s not go down the potential deformation path.

Nor defamation path.

**DiscoDB** · 4th December 2025, 10:27 AM

Hopefully Tombie can give an update on his under bonnet lithium battery.

One of the concerns I would have is the BMS over temp cut out. Many are set around the 80 degree Celsius mark. I see over 70 degrees at the battery in summer and this in Melbourne.

I feel they really need some form of forced cooling.

**Captain_Rightfoot** · 4th December 2025, 11:03 AM

Do the lithium cranking batteries use a capacitor to generate the amps?

**DiscoDB** · 4th December 2025, 11:39 AM

No - most likely use A123 pouch cells for cranking battery use. These are rated for high continuous discharge current and high peak currents. Often used in mild hybrids (in the 48v configuration).

**oka374** · 5th December 2025, 06:54 AM

Don't even think about it I've just lost a vehicle after the one week old Lithium starting battery set it on fire when it shorted internally
I'll provide more info once the insurance is sorted.

**Captain_Rightfoot** · 5th December 2025, 05:15 PM

Originally Posted by oka374

Don't even think about it I've just lost a vehicle after the one week old Lithium starting battery set it on fire when it shorted internally
I'll provide more info once the insurance is sorted.

That''s horrible!

Custom lithium made a battery for my camper. When asked they said "if there is an internal short the mosfets blow and that isolates the cells". Some must be made differently.

**DiscoDB** · 5th December 2025, 05:53 PM

Not good at all oka374. Hope everyone was OK.

Do post details or start a new thread. I am sure it would be a concern for many with 12v lithium batteries.

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