Battery inside vehicle.

[Cuppa]

If you intend fully charging it you will regret putting it inside the car! It will gas & stink the car out (smells like rotten eggs), & is an explosion risk. Just needs one little spark in the right conditions. You will of course make your own decision, but for your sake & for others reading this thread I strongly advise against putting it inside the car!
A battery box is unlikely to contain an explosion, & in fact is possibly more likely to result in one (concentrates the gas in a small area). To safely ventilate the battery you need to have it sealed from the interior with an external vent which allows a good air flow. Are you planning a vented door cut in the side of the vehicle with the battery inside a gas tight cabinet accessible from outside on very heavy duty slide outs? If not - for your own safety & comfort - please don’t do it!

IMO the only safe way to carry that battery inside the car without the sealed/vented cabinet is if it is A) very securely fastened down, so you know it won’t go anywhere in the event of an accident/roll over situation and B) that it is NOT ever charged inside the vehicle.

From http://www.hse.gov.uk/pubns/indg139.pdf

12 Hydrogen and oxygen are usually produced inside a battery when it is beingcharged. A source of ignition – for example, a flame, a spark, a cigarette or any hotobject, electrical equipment, a mobile phone – will often cause mixtures of thesegases to ignite and explode. The explosion is often so violent that it shatters thebattery and produces a highly dangerous shower of fragments and corrosivechemicals.

13 Hydrogen and oxygen are produced more quickly as the battery gets close to being fully charged. If you continue charging after the battery is fully charged, a lotof gas will be produced, greatly increasing the risk from explosion.


14 During charging, gas bubbles often become trapped inside the battery. Themixture of two parts hydrogen to one part oxygen produced is perfect for anexplosion. When a vented battery is moved, the trapped gases are released intothe air around the battery. A tiny spark is all that is needed to ignite the gases. Ifthis happens in a confined space (eg inside the battery, or in an enclosure or apoorly ventilated battery room), a violent explosion is likely.


15 The gases that come out of a vented lead/acid battery during charging oftencontain a fine mist of sulphuric acid. Take care to avoid breathing these fumes, andwear suitable eye protection.


16 Valve-regulated (‘maintenance-free’) batteries are much less likely to releasehydrogen than vented batteries. However, it is still important to take care whencharging them. Gas pressure may build up inside the battery if it is charged tooquickly or for too long. If this happens, the pressure relief valves in the battery mayopen and let the gases escape. An explosion is likely if this happens close to anignition source.