Characteristics of winter operation
There is an opinion that the lower the temperature, the faster the battery drains. This is not so – after all, chemical reactions in the cold proceed more slowly. This means that the battery, like food in the refrigerator, loses its working properties more slowly than in hot weather.
In itself, the capacity does not disappear in the cold: it is often used by car owners who warm the frozen battery in a warm bath. After such water procedures, the battery “wakes up” without additional charging – the starter turns the engine vigorously.
And the number of energy consumers in winter is not much higher than in summer. Indeed, in hot weather with high humidity, you also need to turn on the electric heating of the windows, drive the heating fan at high speed, due to overheating, a powerful electric fan of the engine cooling system often turns on. Let’s add wipers and headlights to the list of energy consumers – it turns out about the same as in winter.
Unless we also use heated seats and a steering wheel in winter. They consume a lot of energy, but they do not work constantly and for a short time.
So why is it in winter that batteries fail more often?
There is no doubt that oil thickened in the cold during start-up requires higher energy costs. But the generator must quickly compensate for the losses. This is where the main difference between winter use and summer use is hidden!
Don’t expect returns
The generator runs honestly and generates energy, but the battery… won’t charge!
Why is this happening? The battery has an internal resistance that depends on many parameters, including temperature. Then Ohm’s law works: the resistance increases – the current decreases.
And therefore the battery charging characteristics at + 20 ° C and – 40 ° C differ dramatically.
In practice, this means the following: the lower the temperature, the less the acid battery can charge. And you can’t help it – this is the design feature.
Amps and degrees
For those interested in real numbers. Here are the results of one of our experiments.
We took several fully charged batteries of the popular size 278 × 175 × 190 mm, made with different technologies – AGM, EFB and “normal”.
They discharged them, but not completely – otherwise the battery can simply break in severe frosts. We limited ourselves to a voltage level of 12.24 V. Then we measured the magnitude of the charging current at room temperature.
The batteries were driven in charge-discharge modes, then fully charged and discharged back to 12.24 V.
After keeping the empty batteries at temperatures from minus 30 ° C to zero for two days, they tried to charge them without taking them out of the freezer.
At minus 30 °C, the charging currents ranged from 0.7 to 1.6 A, ten times lower than at room temperature.
QED
The dependence of the battery charging current on the temperature
|
|
Topla AGM Stop-n-Go 70R 760 a |
Beer EFB 75 Ah 750 A |
Tyumen Battery Standard 75 Ah 660 a |
|
Charging current at 20 °C |
29.0 A |
28.0A |
28.0A |
|
Charging current at 0 °C |
7.1 A |
7.0 A |
7.0A |
|
Charging current at -10 °C |
3.9 A |
3.8A |
4.0 A |
|
Charging current at -30 °С |
0.7A |
1.5A |
1.6A |
Theory and practice
In practice, this means something like the following. Spending huge currents in the cold (hundreds of amps for each start and tens of amps for the rest of the time), the battery returns only miserable crumbs of energy for a long time.
During a long drive, when the engine compartment warms up, the charging current increases. And the battery can quickly make up for the wasted joule.
But for short runs, she has no such opportunity. Particularly bad things are for batteries that are structurally in an open space, like many vans.
But what about?
If you want to insulate the engine compartment, use special thermal blankets and not an old quilted jacket: it could catch fire…
To avoid the problems described above, it is advisable to take long trips from time to time so that the battery warms up and recharges.
If there is a prolonged severe frost in your region, it is advisable to insulate the engine compartment of the car. Then the temperature in it will rise faster. As a result, the battery will warm up faster and be able to charge the generator sooner.
When placed on the frame, the battery must be periodically charged from a stationary source.
But the so-called thermal cover for the battery does not solve the problem. It protects the battery from overheating in summer. And in winter only harm – the battery in the case heats up more slowly.
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