GU1 TD42T cooking 2nd batteries

Hello,

I installed on of these last year and have just cooked my 2nd, 2nd battery.

I have been told that it was heat both times and do not have much spare cash laying around to keep this up.

I really want to keep the battery there, if possible as maximizing space in the wagon is a priority (it's a long drive to woolies :)).

Any ideas for protecting my 2nd battery from under bonnet temps?

I have seen discussions suggesting foil blankets , electric fans and even a bonnet scoop. It's a pretty tight squeeze to get the bare battery into the tray and the least mucking around would be better.

Even if I do manage to protect the battery better, have we come to a consensus about which type/brand/model of battery would stand a chance againgst my under bonnet temps?

Thanks in advance,

Cam

I don't know about patrols, but I've had quite a few high performance turbo cars with outrageous under bonnet temperatures but I have never damaged a battery (even though I have melted a plastic clutch master cylinder.

A few european cars come standard with battery insulators, it is a case made of insulating blanket type material that the battery sits in under the bonnet, I think it is actually meant to prevent the battery freezing, it is standard fitment on some holden barina, astra and vectra models. I imagine they would be dirt cheap from a wrecker.

I would be very careful with foil blankets mate. Can't understand what the problem would be. I've got a second battery and so have most of the guys I know and haven't had a problem with overheating. Are you shore it's not overcharging or too much load. Is your VSR working properly?

I assume VSR is a dual battery system?

I was using one of these and have just installed one of these

Quote:

---

Originally Posted by NotTortoise

I assume VSR is a dual battery system?

I was using one of these and have just installed on of these

---

Yes sorry mate, Voltage Sensitive Relay. The one in you link "these". The idea is that it will allow the alternator to charge your cranking battery until a certain voltage then connect the second battery for charging, if the voltage falls too low it will fall back to charging the cranker only. The only time I have ever cooked a battery, and I have the same setup as you, is when my alternator voltage regulator failed and I was charging at over 17 volts. Have you or can you measure your alternator output? Might also be an idea to PM yendor - he is a gun with electrical.

I also have the Projecta battery monitor and the highest reading I've seen is 14.2V, would that be enough to do damage?

Do you know what sort of battery you are running for your second battery? AGM type or wet cell ect?

Quote:

---

Originally Posted by NotTortoise

I also have the Projecta battery monitor and the highest reading I've seen is 14.2V, would that be enough to do damage?

---

14.2 is a bit high but I think it should be OK. Is that at fairly high revs?

Running lead acid batteries.

14.2 was pushing it on the highway

Sent from my SM-G900I using Tapatalk

Lead acid should be fine as long as they are not AGM Type (absorbed glass matt) and 14.2 volts is spot on for charging voltage

I am told the Calcium batteries handle the engine bay temps the best. I have been monitoring my engine bay temps with a thermo-couple for the last few months, and will see temps ranging from 55 C to 65 C or even 70 C when nearer the turbo. It varies quite a bit from place to place actually, and a lot seems to depend on the ability of the air to escape out of the engine bay, which is usually downwards and under the car. The more air you can get flowing through the engine bay, the lower the air pressure, which in turn assists airflow through the radiator and front grill.

All advice I have read indicates that batteries simply can't handle those sorts of temperatures for long periods of time. Some will last better than others, but it gets to them all eventually.

Collyn Rivers has written a bit about it, and has an excellent table in one of his books describing the expected life reduction of a battery with given heat ranges.

What sort of time frame are you talking about in between each battery?

I should clarify that I am in Nth Qld and those engine bay temps were normal hot days and taken in locations both beside and above the engine itself, plus on the battery. Temps are often down in the 40's along the firewall on cooler days.

The first lasted nearly a year and the next one only 7 months. It was just a basic Century yellow top though

Not good. Is your engine overheating? Are there any other indicators of heat issues?

They aren't just trying to dodge a warranty claim are they?

Maybe get it load tested at Battery World or some other place and see what they say?

I had to send it to Mt Isa as it is a long drive to go for just that. They said that the volts are going up but the cranking amps are not.

A lot of my driving is open highway for 5-30 hours at a time. I know that I can push it a bit and when I sit on 110ish my EGT are around the mid to high 300s.
(at the dump pipe.)

They also said that there is a slight swell in the casing so they are bot going to warranty it.

The battery before "split", but I wasn't in town to see it.

Sent from my SM-G900I using Tapatalk

I know that air temps up here are consistently pretty high. We are currently mid to high 30's all day long. Gotta love winter up here ☺

Sent from my SM-G900I using Tapatalk

As far as I know, swelling is caused by over charging. Overcharging create excess hydrogen gas in the battery faster than what the battery can expel it.

sealed batteries have explosion caps on the top, My battery guy will sell any battery I want
,but will not fit it, I have since fitted a turbo beanie to keep temps down on the Aux battery side.
I have noticed that I need to top up the battery less,
my AUX is a Trojan wet cell 115ah more bang for your buck IMO.
My start is an AC delco sealed. If worried about under bonnet temps fit some vents.
but I think its a charging problem.
what condition are the bushes in the alternator like.
from past experience if they are only touching on their edges it can cause
over charging resulting in boiling the battery not something you'd want

All sealed batteries need a vent. As when they are charging they create the gas which needs to go somewhere...

Maybe get your alternator checked out as something seems wrong. I take it that your starter is OK?

I am running an AGM (DEKA) battery under the bonnet of my 3 litre. I am charging it via a Redarc BC:DC 1220 charger and it has been fine for the last 2.5 years in a variety of temps. It's cool in Adelaide at the moment but gets pretty hot in summer. My alternator starts charging above 14 volt when it starts up but after a while drops off to 13.8 - 13.6 volts as the batteries charge up. Is yours constantly above 14 volts regardless of time? Maybe that's the problem.

When you have your headlights on at night, can you see a slight flare (brightening) when you rev the engine. If so you may have a regulator problem in the alternator. As has been suggested by many of us, myself included, 14+ volts is accemtable but shouldn't be at that all the time.

Quote:

---

Originally Posted by mudski

All sealed batteries need a vent. As when they are charging they create the gas which needs to go somewhere...

---

Optima and a few others dont

Quote:

---

Originally Posted by threedogs

Optima and a few others dont

---

You sure? When batteries charge they let of gas, it needs to go somewhere. I cant say for agm or gel batteries. But lead acid...

Sent from my SM-P600 using Tapatalk

The AGM's like the optima and DEKA are sealed. That's why when AGM's are cooked they swell as there is no where for the gas to escape.

Quote:

---

Originally Posted by Rock Trol

The AGM's like the optima and DEKA are sealed. That's why when AGM's are cooked they swell as there is no where for the gas to escape.

---

If thats the case, a deep cycle would be a better option for under the bonnet then wouldn't it? I know my deep cycle has a breather.

Sent from my SM-P600 using Tapatalk

It's why a lot of AGM's fail under the bonnet. I took a chance with the DEKA Intimidator ($399) as its rated for under hood installation and then I bought a redarc charger ($300) to hopefully charge it without cooking it.
The reality is that I would have been financially better off with another wet cell ($199) battery and changing it over every few years. The AGM is still going strong so it all depends how long it lasts. If it was not under the bonnet you would expect maybe 6-8 years of service life? If I only get 3-4 under the bonnet then the next one will be a calcium deep cycle. I'm crossing fingers it lasts.