Technically could a radiator hold an electrical charge?
Discussion
I have a weird problem - my battery voltage is 12.6 however when I Earth to the radiator it's 13.6
I found a previous owner had shorted something to the radiator which I have now removed but I can't understand how the radiator is 1 volt higher than the battery
I have disconnected the battery negative and tested the battery again still the same 12.6 volts hence the question if you run a positive charge through a radiator for a period of time could it hold a 1v charge for a short period ?
I found a previous owner had shorted something to the radiator which I have now removed but I can't understand how the radiator is 1 volt higher than the battery
I have disconnected the battery negative and tested the battery again still the same 12.6 volts hence the question if you run a positive charge through a radiator for a period of time could it hold a 1v charge for a short period ?
No, it can't.
But then your first sentence makes no sense, so I am not sure what you mean when you say "when I earth to the radiator".
Do you mean if you earth the radiator to the chassis/engine, do you mean if you connect your meter between the battery + & the radiator, or something completely different?
But then your first sentence makes no sense, so I am not sure what you mean when you say "when I earth to the radiator".
Do you mean if you earth the radiator to the chassis/engine, do you mean if you connect your meter between the battery + & the radiator, or something completely different?
Edited by E-bmw on Friday 17th December 08:33
KTMsm said:
One probe on the battery positive, one probe on the radiator leads to an increase of 1 volt
Running or not
Is there a voltage difference between the radiator and the vehicle ground eg an exposed point of the engine?Running or not
There is slightly over 1V difference in the galvanic voltage of aluminium and iron/copper, so if an aluminium radiator is not grounded and the engine has an iron block you might be able to read some of this if the passivation in the coolant has been depleted.
Yes it can, that is exactly why you are supposed to change your coolant every few years. Once the corrosion inhibitors in the coolant become ineffective the cooling circuit turns into a single battery cell, with dissimilar metals inside the coolant acts as an electrolyte and internal corrosion accelerates massively once this happens. Flush your cooling system and change your coolant.
OldGermanHeaps said:
Yes it can, that is exactly why you are supposed to change your coolant every few years. Once the corrosion inhibitors in the coolant become ineffective the cooling circuit turns into a single battery cell, with dissimilar metals inside the coolant acts as an electrolyte and internal corrosion accelerates massively once this happens. Flush your cooling system and change your coolant.
Great answer.Is this a simple way of measuring your coolants degradation? i.e. put one probe on battery earth terminal and the other in the coolant and the voltage is somewhat proportional to the coolant degradation?
There isnt really a hard and fast rule as every cooling system has a different amount of aluminium, copper, steel and brass in it and different types of coolant so will give different readings, but 1v is a bit on the high side, as a proper battery cell is between 1.2 and 2v
On the us classic car forum I first learned about this phenomenon 0.3 to 0.4v was their threshold for changing coolant, but I dont know if thats overkill or not. I just do my coolant every 2-3 years along with the brake fluid as fluids are cheap and easy to change and the accelerated wear and sticky calipers and leaking head gasgets and stuff arent as cheap and easy to fix.
On the us classic car forum I first learned about this phenomenon 0.3 to 0.4v was their threshold for changing coolant, but I dont know if thats overkill or not. I just do my coolant every 2-3 years along with the brake fluid as fluids are cheap and easy to change and the accelerated wear and sticky calipers and leaking head gasgets and stuff arent as cheap and easy to fix.
This was IMO the most comprehensive answer I found after googling:
Electrolysis is a destructive force that packs enormous potential to damage not just cooling system components, but to any aluminum engine part that has contact with the coolant. There are 2 distinct types of electrolysis, one caused mostly by improper grounding issues, called Type A, and the other primarily due to the chemistry of the coolant, called Type B.
In a nutshell, if your electrolysis goes away when the battery is disconnected, you have Type A. If your electrolysis remains, you have Type B.
Type A electrolysis involves an incomplete circuit, typically a poor ground, that uses the coolant as a return path. This type of electrolysis is generally easy to isolate by pulling fuses etc. To establish the presence of Type A electrolysis, removal of a battery cable at the post is necessary.
Type B electrolysis is similar to the dynamic of a battery. The coolant acts as a catalyst and allows and encourages ion movement, just like the electrolyte in a battery. The "electrodes", are the aluminum components in the cooling system (like the lead plates in a battery).
Prevention
Can Electrolysis be prevented? Absolutely! The key to the prevention of Type B electrolysis simply means not letting the coolant wear out. When the antifreeze/coolant wears out, it acts like the acid in a battery, allowing dissimilar metals to react, and create a voltage.
Change the coolant every 2 years.
Testing for Electrolysis
Can Electrolysis be measured? At the heart of any electrolysis discussion is it's measurement. If it can be measured, it's presence can be verified, which is extremely important when we are classifying, treating, and removing the electrolysis. To get started, lets take a couple of simple measurements, with a digital VOM (volt/ohm meter).
1) Simply attach the negative lead of the voltmeter to the engine block, or other known good ground, and with the positive lead, dip it in the coolant. Unless you read zero, you have electrolysis. If you measure less than .1v, your cooling system should be below the action level. If you measure .2v or above, keep reading.
2) Next, repeat the test with the positive battery cable removed. Still reading .2v or above? It's not a loose ground your after....the voltage is coming from within, and you most likely have type B electrolysis.
If your voltage dropped when battery was disconnected, you most likely have type A electrolysis. Type A may be isolated to a switched circuit, and must be isolated in much the same manner as finding a voltage draw: circuit by circuit. It may just be a loose or missing ground. It may be much more.
Regardless, if you have a reading of more than .2v, (two tenths), you may have damaging electrolysis.
Aluminium damage will begins to occur at .3v
Type B electrolysis is similar to the dynamic of a battery. The coolant acts like a catalyst and allows and encourages ion movement. The "electrodes" defined above, are the aluminium components in the cooling system (like the lead plates in a battery). The "electrochemical process" mentioned is the aluminium particle (ion) movement, such that leaks occur. When enough ions have moved, this results in a failure (leak) typically in the radiator . A thicker surface (like an aluminium casting) is not more resistant to electrolysis, but is not as likely to leak because it is thicker. However these thicker surfaces may leak anyway if the electrolysis occurs at a gasket surface
Electrolysis is a destructive force that packs enormous potential to damage not just cooling system components, but to any aluminum engine part that has contact with the coolant. There are 2 distinct types of electrolysis, one caused mostly by improper grounding issues, called Type A, and the other primarily due to the chemistry of the coolant, called Type B.
In a nutshell, if your electrolysis goes away when the battery is disconnected, you have Type A. If your electrolysis remains, you have Type B.
Type A electrolysis involves an incomplete circuit, typically a poor ground, that uses the coolant as a return path. This type of electrolysis is generally easy to isolate by pulling fuses etc. To establish the presence of Type A electrolysis, removal of a battery cable at the post is necessary.
Type B electrolysis is similar to the dynamic of a battery. The coolant acts as a catalyst and allows and encourages ion movement, just like the electrolyte in a battery. The "electrodes", are the aluminum components in the cooling system (like the lead plates in a battery).
Prevention
Can Electrolysis be prevented? Absolutely! The key to the prevention of Type B electrolysis simply means not letting the coolant wear out. When the antifreeze/coolant wears out, it acts like the acid in a battery, allowing dissimilar metals to react, and create a voltage.
Change the coolant every 2 years.
Testing for Electrolysis
Can Electrolysis be measured? At the heart of any electrolysis discussion is it's measurement. If it can be measured, it's presence can be verified, which is extremely important when we are classifying, treating, and removing the electrolysis. To get started, lets take a couple of simple measurements, with a digital VOM (volt/ohm meter).
1) Simply attach the negative lead of the voltmeter to the engine block, or other known good ground, and with the positive lead, dip it in the coolant. Unless you read zero, you have electrolysis. If you measure less than .1v, your cooling system should be below the action level. If you measure .2v or above, keep reading.
2) Next, repeat the test with the positive battery cable removed. Still reading .2v or above? It's not a loose ground your after....the voltage is coming from within, and you most likely have type B electrolysis.
If your voltage dropped when battery was disconnected, you most likely have type A electrolysis. Type A may be isolated to a switched circuit, and must be isolated in much the same manner as finding a voltage draw: circuit by circuit. It may just be a loose or missing ground. It may be much more.
Regardless, if you have a reading of more than .2v, (two tenths), you may have damaging electrolysis.
Aluminium damage will begins to occur at .3v
Type B electrolysis is similar to the dynamic of a battery. The coolant acts like a catalyst and allows and encourages ion movement. The "electrodes" defined above, are the aluminium components in the cooling system (like the lead plates in a battery). The "electrochemical process" mentioned is the aluminium particle (ion) movement, such that leaks occur. When enough ions have moved, this results in a failure (leak) typically in the radiator . A thicker surface (like an aluminium casting) is not more resistant to electrolysis, but is not as likely to leak because it is thicker. However these thicker surfaces may leak anyway if the electrolysis occurs at a gasket surface
MikeStroud said:
Is this a simple way of measuring your coolants degradation? i.e. put one probe on battery earth terminal and the other in the coolant and the voltage is somewhat proportional to the coolant degradation?
No, that's leaving it too late to detect the problem. By the time you see a significant voltage the passivation in the coolant is depleted and the engine is suffering corrosion. You should aim to renew the coolant way before then.GreenV8S said:
MikeStroud said:
Is this a simple way of measuring your coolants degradation? i.e. put one probe on battery earth terminal and the other in the coolant and the voltage is somewhat proportional to the coolant degradation?
No, that's leaving it too late to detect the problem. By the time you see a significant voltage the passivation in the coolant is depleted and the engine is suffering corrosion. You should aim to renew the coolant way before then.MikeStroud said:
GreenV8S said:
MikeStroud said:
Is this a simple way of measuring your coolants degradation? i.e. put one probe on battery earth terminal and the other in the coolant and the voltage is somewhat proportional to the coolant degradation?
No, that's leaving it too late to detect the problem. By the time you see a significant voltage the passivation in the coolant is depleted and the engine is suffering corrosion. You should aim to renew the coolant way before then.Gassing Station | Home Mechanics | Top of Page | What's New | My Stuff