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You’ll end up with a totally flat battery and no start.
Run a simple calculation to estimate time taken to heat engine oil:
Assume heat capacity 1670 J/kgK. Oil temperature increase 20C. 100 Watt electric heater.
Not allowing for inevitable heat loss, time in seconds to heat 3 litres of oil 20 degrees C becomes thus:
t = 1670 x 3 x 0.9 x 20/ 100 = 902 seconds = 15 minutes.Last edited by tolsen; 19-12-17, 06:48 AM.
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My oil pan heater is rated at 150 Watts and is fully immersed in oil. In cold weather, to get any appreciable increase in oil temperature, I must keep the heater turned on for several hours. No problem as a 240 volt AC heater and AC is available where the car is normally parked.
My conclusion is that a 12 volt heater powered by starter battery is a total non starter.
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It's just a helper that prolongs the life of the engine .
However, supplementation of electric capacity is required. Classically by increasing battery capacity to 75Ah .
It's more complicated with an additional supercapacitors battery. The advantage is that it's easy and can go home in the evening (load at 230Vac possible).
By using electrical power we moved the mess elsewhere .
Heat losses are greater than 10% but the capacity of the oil pan is 2.7 l .So it compensates .
I understand it is but an estimate ;this aspect is also mentioned .
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2.7 liters of oil are 2.3 kg and the heating resistance will be 200W.
Heating is provided with the UVLO circuit and overheating circuit breaker .
Anytime it can be powered (230VAC) if it is possible.
Also load and battery => soft start / minimal wear, increased MTBF.
Charging is also possible with a 230V resistor but practically impossible from the starter battery.Last edited by mottofreee; 19-12-17, 11:46 AM.
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Sorry for abbreviations, I'm work in the area and to use familiar terms.
UVLO is a device that detects when voltage drops below a certain threshold (predetermined) and interrupts power supply: https://en.wikipedia.org/wiki/Undervoltage-lockout
MTBF is an estimate: https://en.wikipedia.org/wiki/Mean_t...tween_failures
I said:
- the quantity of bath oil is 2.7 l with a mass of 2.3 kg.
- 300W (150W'150W) heating resistance, unfortunately I wrote 2 00 instead of 3 00
-a battery capacity increased to 75Ah (from 63Ah OE)
-power supply to the network) 230Vca = who has access
-reduces engine wear and starter wear - refined engine is £ 1,000 + workmanship, the new starter motor is £ 200 + workmanship .
-12V-75Ah Battery (premium class) £ 60 with workmanship included .
New:
Suppose 300W in 5min means 300W / (300/3600) h = 3.6kW / h; the OE battery has the capacity to deliver 480A x 12V = 5760W (5s @ -18C) and the capacity reserve over 90min (up to 10.5V with a current of 25A).
At -18C the theoretical battery capacity is 60% from 100% to + 20C.
Suppose 300W in 5min means 300W / (300/3600) h = 3.6kW / h; the OE battery has the capacity to deliver 480A x 12V = 5760W (5s @ -18C) and the capacity reserve over 90min (up to 10.5V with a current of 25A).
At -18C the theoretical battery capacity is 60% from 100% to + 20C. For the battery would be good thermal insulation of the battery housing.Last edited by mottofreee; 20-12-17, 03:14 PM.
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Originally posted by mottofreee View PostIt's just a helper that prolongs the life of the engine .
Mobil 1 is a triumph of marketing over substance. If they had spent a fraction of the marketing budget on developing the product, it might be good by now.
When I had my engine apart at 76,000 miles (fuct rings) the old crank shells were exactly the same dimensions as the new ones. I'm told that when run on Mobil1 and stripped at lower mileage (for the same reason - rings), shells are worn through to the copper backing. Needless to say, I wasn't running on Mobil1.
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Currently I use Mobil 1 Turbo Diesel 0W40. https://www.mobil.com/English-BE/Pas...bo-Diesel-0W40
For some reason, the OM660 resists little compared to other engines.
I want to last longer.
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If this is the same Mobil product http://www.halfords.com/motoring/eng...0w-40-5-litres it is API CF. API CF dates back to 1992.
I use the 15W/40 (10W/30 also available) of this - which is API CK.
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I am still not convinced that there will be sufficient remaining power to start engine once you have tapped off valuable battery power to heat sump.
Have you ever heard of Peukerts law? Look it up on Wikipedia.
The thing is 75 Ah rating is based on a very low discharge current typically the 20 hour rating at 3.75 A. Same 75 Ah hour battery may only have 7.8 Ah if drawing 17 A to heat your sump with 300 Watt heater. Its rating for starting at minus 20 may be no more than 0.4 Ah. That explains why often a battery will be dead after cranking for only ten seconds when really cold.Last edited by tolsen; 21-12-17, 07:48 AM.
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For example, for a 70Ah battery http://www.rombat.ro/ro/catalog/auto...er-12-v-70-ah/
The starting current is 680A and can support this current for 10 seconds and the final voltage is 7.5V. This tension leads to the irretrievable loss of capacity.
The minimum voltage for which the battery is not affected is 10.5V.
A 12V battery is considered 0% charged when the battery has 12.0V (open circuit).
Connect glow after 10s of heater rest.
That is, when the contact key is inserted, wait for 10s.
Anyway can use a additional supercapacitors battery for this purpose. I think this is the best solution.
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Yes, safer using dedicated battery perhaps a 12 volt sealed battery that can be stored inside house and charged both by car after start and when stored inside house.
You could also consider adding starter handle and cylinder decompression mechanism.
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