Deep cycle <span class="highlight">battery</span>

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Indeed SSB do allow their AGM's to be placed Under the bonnet, and still maintain warranty.

They speak of...."State-Of-The-Art Thermal Management System - Keeps battery cool during charging & general use making it better suited to hotter climates (like Australia’s top end) and under bonnet use."
I would love to know how they achieve that.

Each battery thoroughly polished with Snake Oil, Allan, before they leave the factory?

Bob

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There's gotta be a catch!!

OK to place battery under bonnet.... just don't start the engine?

I have had 2 SSB batteries in the engine bay of our Nissan Patrol for 3 years - one for starting and one for accessories. They are controlled by a system purchased and installed by ARB 10 years ago. A button in the cabin allows me to use both batteries to start the vehicle to ensure that the second battery is used a bit when we are not on a trip etc. I had them tested recently and they are both fine - the accessories battery was slightly more healthy than the starter one. I will replace them with the same batteries when I need to.
nats.

I, like Allan, are puzzled as to where the SSB battery Thermal Management System is. You buy one of their batteries, it looks like a battery, feels like a battery, works like a battery and is in fact a battery, That battery placed in an underbonnet location gets the same heating as any battery will receive in that location. SO, unless there is a physical insulation system and appropriate airflow the battery will get just as hot.
Many stop/start batteries do have insulation and some are at rear of engine bay too and still get engine bay heat, but may be protected slightly from direct radiant heat which will total any battery.
If said batteries are located at front of engine bay, then they are largely removed from the bay heat by having airflow almost directly to them before the engine bay. They must then run cooler. Usually people don't state WHERE the in the bay the batteries they have success with, actually are. Position makes a BIG difference to battery life. No one to my knowledge has taken battery temp readings of various UB locations and ambient temps to determine anything definite regarding battery life. So many variables, a simple recommendation from one person may be the battery killer for the one reading and asking for info because their fitting is an entirely different heat location..
Can the battery get cooled? Is it in the turbo radiant heat side? Is it insulated from direct radiant heat? Is it cushioned from vibration?, most are not.

Maybe the external battery shell is of a different type of material. All batteries look like, feel like and act like batteries....yet internally (where we cannot see) they can be completely different. I know many of people have had good success with optima under the bonnet. Century/Yuasa also advertise an under bonnet agm. These under bonnet batteries are made from a different polypropylene material (normal batteries are ABS). Yuasa/Century are high quality, reliable batteries. The more heat resistant the outer casing the cooler the internals.

Maybe technology has caught up and agm can be used like any battery.

HEAT CAN KILL ANY BATTERY. I know plenty of people in top end who only get a couple of years out of batteries...others many years.

Nats, you’ve had what I would consider a reasonable life out of those batteries. And they’re still going.
I know we would all love to get 5,6,7 or 8 years out of our batteries. But reality is most don’t. I’ve had long life out of some , and bloody short out of others. It’s a lottery.
I was told ( while I was in the retail industry) that batteries, are a grudge purchase. As in most people hate having to replace them . It’s true isn’t it?
But look at it like this in say three years , how many dollars worth of fuel , tyres etc do you put thru a vehicle . At the end of the day it’s a small part of the running cost.
I had this with farmers that would winge and complain about batteries. When they would be spending 50 to 100 grand on fuel, and a hell of a lot more on fertilisers and pesticide and herbicides. Their battery bill was pretty small in comparison!
It all about perception!
Cheers All

SSB warrant their AGM’s for 3 years and they say the batteries are designed to be used under the bonnet.

How they do it from a technical perspective, I don’t know.

I have had mine for 20 months and it seems to perform better than the marine deep cycle batteries that I have used in the past.

Time will of course tell.

I've had a Fullriver 120Ah AGMbattery at the front under the bonnet of my 80 Series Toyota for 8 years next month, it is just showing its age now.

Lloyd Mac

"The more heat resistant the outer casing the cooler the internals."

The casing may be heat resistant but that doesn't mean it offers good insulation properties to the internals, ie the plastic encapsulating semi conductors is virtually melt proof, heat it up it with a soldering iron it does not melt, however also has very good heat transfer properties heat up one end while holding the other and you will be quickly burnt by the heat transfer through the plastic.

I have recently installed a battery monitor to a Lithium dropin I have installed under bonnet, the temperature sensor is attached to the battery terminal so should give a reasonable picture of the internal battery temperature as the battery has a 3C current rating therefore a reasonable amount of copper connecting the post to the internals. Looking at the temperature of the battery through the day with the car garaged shows the ambient temperature. Monitoring the battery during a test drive showed thebattery to get hotter than the environment but to be honest can't recall what it got up to. It was cooler than the engine bay but hotter than the environment. In my case the battery is mounted behind the headlight in a cool air stream away from heat sources apart from the radiator so for highway driving one would expect it to be cooler than the engine bay. For stop start driving eventually the battery will get to under bonnet temperatures, how long this takes will be more dependent on the mass of the internals than any likely insulation properties of a solid plastic case.

Bottom line is you would need a thick layer of insulation to stop heat getting into the battery, I have never seen any battery with internal insultation of any sort. Having a lot of lead inside the battery will slow the heat rise but eventually the internals will be the same temperature as the ambient or hotter.

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Bigfish,

Certainly, premium batteries such as Optima are more durable but no battery enjoys heat. The cooler they are kept, the longer they will last.

On the subject of heat resistant battery cases I agree that some casing material would be more durable than others. However no insulation closely wrapped around a battery (or any other object for that matter) will keep it cooler unless cooling air is circulated between the insulation and the battery. All insulation will do is slow the transfer of heat through the insulation but with time the internals will reach the same temperature as the embracing environment.
Actually, in the case of a working battery, adding close insulation, whether it be casing or wrap, will increase the battery temperature because heat is being generated within the battery and needs to dissipate out to the environment to keep the battery temperature from rising.

Insulation can be used to shield engine heat provided that cooling air is circulated past the battery, as in my Troopy as per the photo below. Note that since that photo, the AGM battery has been relocated to the cabin. The heat shield remains to improve the environment for the cranking battery.

I have recently replaced a still working 9 year old 120Ah Fullriver HGL standby battery that I have been using as a crank in the OKA.
I replaced it with an "unknown brand" AGM of similar size.
It is NOT under the bonnet.
Previous wet cell cranks in the same spot have lasted under 3 years. Killed by corrugations.
Cheers,
Peter
OKA196 motorhome

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Peter, 9 year battery life? Wow! There is no doubt that Fullriver are good.
I believe that corrugations have contributed greatly to the demise of my various under-bonnet batteries, both flooded cranking and AGM. The batteries were directly above the front wheel and the Troopy is not well known for a soft suspension! Heat was managed with the shield in the Followup above.
The AGM is now with its mate in the cabin approximately halfway between front and back axles so hopefully more comfortable. Simple physics now dictate half the shock intensity but double the frequency. Time will tell.

Just a further point about my 2 three and a half year old SSB batteries : they have not had an easy life. We travel on the Len Beadell tracks every year and have done the Canning as well. The corrugations on those tracks are magnificent examples of their kind. We have no heat shield and the accessories battery is not far from the turbo. We run our Engel 40ltr. on freeze and store food in the Two Zone that sits atop the Engel so the second battery gets a belting. From my experience I don’t know what all the fuss is about having AGM batteries in the engine bay.
nats.

I always paint mine white before I install them for heat reflection.
Dave.

Peter

Fullrivers are good batteries but prone to heat damage; I suspect your particular placement and the exposure to heat in your OKA has a lot to do with it;

My Fullriver lasted 2.5 years under the bonnet of my 200 LC before it ballooned.
CJ

CSeaJay...I dont think fullriver are any more prone to heat than the vast majority of batteries on the market. In actual fact they may be more tolerant.....reason I say this is because they are normally heavier (more lead on the internals) than most batteries advertised at the same or near amperage..

Heat versus batteries is an 'argument' of the likes of Toyota vs Nissan , BFG vs Coopers ..... Wifes Jeep , 2005 Turbo Diesel , hot as hell under bonnet , factory fitted Optima Red Top ,15 YEARS still going strong [yep heat kills batteries ] .... 90 amp hr Fullriver AGM bought August 2002 as an AUX , has been in 3 different vehicles 'under bonnet' , all turbo diesels [ no extra shielding done] , still going strong , part and parcel is to keep it 'simple' , no fancy expensive charging 'system' , a plain old smart solenoid and heavy thick wire .....

You have been lucky...nothing more to it. For every story of a battery lasting 7-10 years there are dozens more telling of short life. Its ok for you as you drive a vehicle 15 years old...technology has come a long way. Smart systems are totally different to just chucking heavy gauge wire on and a simple solenoid. Obviously you dont agree with the fact that heat is a batteries greatest enemy...as acknowledged by virtually every battery manufacturer, battery forum and the vast majority of off road forums. A lot also depends on what amperage and how often you are cycling the battery. So many variables between users. Heat versus batteries is absolutely nothing like ford vs holden. I,ve never seen anyone state that heat doesnt affect batteries...up until now!!!!

Bigfish , perhaps you need to read up on the history of AGM batteries , originally designed for use in spacecraft , where extremes of HEAT followed by extreme COLD ......yes technology moves on , tell me why my old Nokia 101 mobile phone battery lasts 3x longer than my new beaut Apple ........

Well Alloy I did look at the history and just as I thought you are wrong!!again!

"History

The first lead-acid gel battery was invented by Elektrotechnische Fabrik Sonneberg in 1934.[6] The modern gel or VRLA battery was invented by Otto Jache of Sonnenschein in 1957.[7] The first AGM cell was the Cyclon, patented by Gates Rubber Corporation in 1972 and now produced by EnerSys.[8] The cyclon is a spiral-wound cell with thin lead foil electrodes. A number of manufacturers seized on the technology to implement it in cells with conventional flat plates. In the mid-1980s two UK companies, Chloride and Tungstone, simultaneously introduced 10 year life AGM batteries in capacities up to 400 Ah, stimulated by a British Telecom specification for batteries for support of new digital exchanges. In the same period, Gates acquired another UK company, Varley, specialising in aircraft and military batteries. Varley adapted the Cyclon lead foil technology to produce flat plate batteries with exceptional high rate output. These gained approval for a variety of aircraft including the BAe 125 and 146 business jets, the Harrier and its derivative the AV8B, and some F16 variants as the first alternatives to then standard nickel-cadmium (NiCd) batteries.

Every battery manufacturer also gives out the temperature range its batteries should operate at for longevity. All of them do not like heat!!

CUT AND PASTE FROM A RESPECTED BATTERY FORUM....
'Heat is a killer of all batteries, but high temperatures cannot always be avoided. This is the case with a battery inside a laptop, a starter battery under the hood of a car and stationary batteries in a tin shelter under the hot sun. As a guideline, each 8°C (15°F) rise in temperature cuts the life of a sealed lead acid battery in half. This means that a VRLA battery for stationary applications specified to last for 10 years at 25°C (77°F) would only live 5 years if continuously exposed to 33°C (92°F) and 30 months if kept at a constant desert temperature of 41°C (106°F). Once the battery is damaged by heat, the capacity cannot be restored.

According to the 2010 BCI Failure Mode Study, starter batteries have become more heat-resistant. In the 2000 study, a rise in temperature of 7°C (12°F) affected battery life by roughly one year; in 2010 the heat tolerance has been widened to 12°C (22°F). Other statistics reveal that in 1962, a starter battery lasted 34 months; technical improvements increased the life expectancy in 2000 to 41 months. In 2010, BCI reported an average age of 55 months for starter batteries, with the cooler North attaining 59 months and the warmer South 47 months. Colloquial evidence in 2015 revealed that a battery kept in the trunk of a car lasted one year longer than if positioned in the engine compartment.

Why does your Nokia last 3 times longer? BECAUSE IT DOESN'T EVEN HAVE THE CAPABILITY TO DO 5% OF WHAT THE I-PHONE DOES!!

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Alloy, lead-acid AGM batteries in "spacecraft"? I really don't think so mate.
Those things needed to actually lift-off the launcher.

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Exactly Dave. No point in getting 'hot & bothered' about it, is there.