CTEK D250S vs REDARC BCD1225 - engine bay mounting / solar regulators

hi
i've read up on the species of them and i cant find any detail in relation to what sort of temperature they will with stand
the species only relate to their charging factors

The more blogs / forums you read the more hair you pull out! Yeah maybe inside the cabin somewhere might be better all round solution for the solar reg / CTEK? That way I guess you're only a metre or so extra away from the battery - just a pain fitting it that's all.

I've got a D250S and it isn't suited to under the bonnet, it also states that if it gets too hot it cuts back the charging rate so would probably give you problems anyhow as far as charging the battery in a reasonable time.

As long as you put in reasonable sized wire then it should be OK to mount it in a cooler part of the vehicle and feed it back to the second battery. Someone on here will know the wiring size required.

Not so, is on the money.
These type of DC/DC system chargers have a maximum temp rating and they DO CUT BACK the charge rate when they get hot/toohot.
If heated in an engine bay they will detect the heat and reudce or eliminate any charge for battery purposes.
The charge rate you then get will be very low and not worth having.

In the engine bay is the worst place you can mount it. On another forum, a BT50 owner tried to do the same thing and after being advised to test the output under engine temp was shocked at what he wasn't getting out of his expensive paper weight.
Relocated to a cool area it worked fine and only needed some additional cable runs.

Ross they do cut back charge rates if they get to hot...65-70 Deg C.

Most engine bays will see about 50-55 Deg C on a 40 Deg C day.

In some vehicles we fit them to we mount them in front of the radiator to help cool.

Engine bays can get a lot hotter than 55c.

On a test done for battery ambients, on a 30c day with little engine load my Troopy got to 68c. See Thread 91116.

Yep, and even if the temp did only reach 55 under the bonnet, the unit produces it's own heat and at 55 ambient, the unit wouldn't be able to cool itself down efficiently anyhow.Mine gets hot sitting in the van in a nice cool cupboard especially when the battery is down a bit.

Allan not every part of the engine bay gets as hot as you have shown, did you take the temp reading in direct flow from the rad fan..... where your battery's are mounted they look like they are in direct air flow from the fan..... were you using air temp, liquid temp or surface temp probes.

What was the temp reading behind the headlights away from the air flow.

If you were 68 deg everywhere in the engine bay the water in your windscreen washer bottle would be hot enough to give you third degree burns. I would suggest to get a bit more cold air flow into the engine bay..... bonnet scoop may help.

Not every vehicle runs as hot under the bonnet or every area under the bonnet as your Landcruiser does.

If you want to do it properly, buy some heat sensitive tape and place it around different parts of the engine bay.... go for a good drive under load and then see what you come up with

And Notso..... because something gets hot it doesn't mean it's too hot or cannot disperse heat.

If something generates 70 Deg of heat load by it's self then that something can work in environments comfortably up to 70 Deg.

If the temp reached the said 55 deg under the bonnet and the unit ran at a constant 60 deg at maximum charge rate.... the unit will not run any hotter and more then likely if it had good air flow it would only run at 55 deg..... hot attracted to cold.

Touching something at 40 deg C with your bare hand can seem hotter than you think it is.

The only true way of finding out heat loading is to get the information from the manufacture of the product and decide if it is suitable.

If you want it to work really well, make a small liquid heat exchanger running of your AC and place the DC DC charger in the liquid if they are water proof (RedArc BCDC's are).

It's all about temperature differentials, if you have a higher ambient then you cannot transfer as much heat from one place to another. It's a bit like having two water tanks with a 1 metre difference in height versus something with a 2 metre difference. A lot more will flow from the higher tank to the lower tank if the height differential is greater.

Now wouldn't it be a lot simpler to use decent size cables and put the thing somewhere where you know it will work!

Hi Olcoolone, Agreed that the temperatures in the engine bay would vary somewhat in differing locations. In the tests reported in thread 91116 I was concerned only with battery temperature so the readings were taken in a) free air from the grille and radiator exit passing the side of the engine and adjacent to the battery location and b) on the other side of the new heat shield close to the battery. Thermocouples were used reading on a DVM.

I had no interest in the temperature behind the headlights away from the air flow, only in the battery environment.

I did not say that the engine bay was "68 deg everywhere" and I'm sure that some vehicles run at a lower temperature..........and probably some higher! I have some trust that Toyota (and others) have designed and constructed their vehicles to run with "acceptable" engine bay temperatures. It is only when we start adding stuff such as AGM batteries and electronic devices that we may need to reassess the situation.

Mounting devices such as DC-DC chargers in the airflow from the headlight aperture or in front of the radiator could be good. I placed my BCDC1220 within 300mm of the battery on the cabin side of the firewall which I thought was "pretty cool". LOL

I thought that I had already "done it properly" with measuring the temperature of my battery environment without need of measuring "different parts of the engine bay". If I was interested in temperature elsewhere I would have measured in the chosen location.

I can see where you are coming from with your "Most engine bays will see about 50-55 Deg C on a 40 Deg C day." but I pointed out that there can be zones where the temperature can be much higher. I have not actually measured it but would think that a favourite mounting place, on the firewall, would be perhaps a very high temperature location. It is in the full stream of the air exiting the radiator and passing over the engine, and even the exhaust manifold.
If you are perhaps concerned with the a/c compressor I would think that is perhaps not so bad being at the front of the engine at least, but you would perhaps be a better judge of that.

And Notso, I certainly agree with your "Now wouldn't it be a lot simpler to use decent size cables and put the thing somewhere where you know it will work!" I have yet to see an electronic device that runs better or lasts longer by running at a higher temperature.