Rectifier Only Charges 53Ah Battery to Half After 10 Hours - Voltage Readings Inside

zwolmar wrote:

Enlighten me.

The warranty card from Centra says that the battery is charged when the voltage reaches 16V.

But they certainly wouldn`t honor the warranty if the car`s alternator produced such voltage. Have you never encountered nonsense written in instructions, especially recently when many devices are MADE IN CHINA and the instructions are poorly translated into PL? This does not free us from thinking.

zwolmar wrote:

But they certainly wouldn`t honor the warranty if the car`s alternator produced such voltage. Have you never encountered nonsense written in instructions, especially recently when many devices are MADE IN CHINA and the instructions are poorly translated into PL? This does not free us from thinking.

Believe me, it`s not stupidity and it`s not a mistake. But I`m tired of this convincing. Let everyone load however they want.

These are two different things - cyclic loading and buffer loading. In the case of cyclic charging, the end of charging should be at a voltage of approximately 15V (15.6V), while in the case of buffer charging there is no end of charging as such, but the voltage should not exceed 13.8V (14.4V) and such a voltage is safe for any length of time. time. In the case of cyclic charging with a current of 0.1C, the charging time should not exceed 14-18 hours, and if the voltage reaches the limit value sooner, charging should be terminated.

tzok wrote:

These are two different things - cyclic loading and buffer loading. In the case of cyclic charging, the end of charging should be at a voltage of approximately 15V (15.6V), while in the case of buffer charging there is no end of charging as such, but the voltage should not exceed 13.8V (14.4V) and such a voltage is safe for any length of time. time. In the case of cyclic charging with a current of 0.1C, the charging time should not exceed 14-18 hours, and if the voltage reaches the limit value sooner, charging should be terminated.

There are a few "tiny" nuances in this matter:
- the winner is whoever determines how much Ah is missing in the battery and how many hours it needs to be charged.
Charging with constant current is good for a new battery (first charging) or a completely discharged one, e.g. traction batteries in electric wheelchairs
-How to determine the end of the charging process when we cannot detect increased gassing or measure the density of the electrolyte because the battery is maintenance-free? The voltage at the terminals during charging is an unreliable and imprecise parameter. It is enough that the internal resistance of the battery will be smaller or larger for some reason and the voltage at the same current of 0.1C will also be lower or higher and does not necessarily mean the state of charge.
- How to force a constant current, after all, the voltage of the battery being charged increases, so to maintain a constant current, we must increase the charging voltage? To meet this condition, the rectifier system must be significantly expanded, and this becomes an example of style over substance. It is of course feasible, but is it profitable in this case?
-Batteries charged with constant current get quite hot, which is harmful to them. The temperature would need to be controlled and cooled if necessary.
-Many newer cars experience an excessive increase in voltage in the installation, and you can also damage something in the car. Therefore, it will be necessary to remove the battery for the simple task of charging.
-charging with constant voltage also has the advantage over charging with constant current that you do not need to control the time, it can last indefinitely, and the pulsating current from the rectifier (so-called sinusoidal peaks) has a "healthy" effect on the battery.
After considering all the "pros" and "cons" (or "positive pluses and negative pluses" - as our former president, the great electrician LW, used to say), let everyone decide for themselves whether to buffer charge up to a maximum of 14.4V or cyclically, up to 15.6V (some give an even higher value).

zwolmar wrote:

How to determine the end of the charging process when we cannot detect increased gassing or measure the density of the electrolyte because the battery is "maintenance-free"?

Based on the rate of voltage rise at constant current.

zwolmar wrote:

How to force a constant current, after all, the voltage of the battery being charged increases, so to maintain a constant current, we must increase the charging voltage?

This can be done easily in the case of a pulse converter controlled by a microcontroller.

tzok wrote:

zwolmar wrote:

How to determine the end of the charging process when we cannot detect increased gassing or measure the density of the electrolyte because the battery is "maintenance-free"?

Based on the rate of voltage rise at constant current.

zwolmar wrote:

How to force a constant current, after all, the voltage of the battery being charged increases, so to maintain a constant current, we must increase the charging voltage?

This can be done easily in the case of a pulse converter controlled by a microcontroller.

This phenomenon is not used in any automatic rectifier that I know of.

Added after 8 [minutes]:

Microcontrollers, miniprocessors and the LEGOO rectifier from the first post - maxi-simplicity. How many of us have switching converters with constant charging current in our workshops? I haven`t seen any like that. I will repeat myself: To meet this condition, the rectifier system must be significantly expanded, and this becomes an excess of form over substance. It is of course feasible, but is it profitable in this case?
You can fire a cannon to kill a fly, or use a swatter.

zwolmar wrote:

This phenomenon is not used in any automatic rectifier that I know of.

This type of solution is much more common in Li-Po battery chargers. In lead-acid battery chargers, sampling in the final phase of charging is more common.

Classic: http://www.ctek.com/pl/en/chargers/MXS%2010

zwolmar wrote:

To meet this condition, the rectifier system must be significantly expanded, and this becomes an example of style over substance.

There are ready-made controllers, there is no problem with that. Such chargers are light, small and safe (they do not require disconnecting the battery from the car`s electrical system), and completely maintenance-free - if you have a vehicle that you use occasionally, you can connect such a charger to it in the garage and forget about it.

zwolmar wrote:

To meet this condition, the rectifier system must be significantly expanded, and this becomes an example of style over substance.

There are ready-made controllers, there is no problem with that. Such chargers are light, small and safe (they do not require disconnecting the battery from the car`s electrical system), and completely maintenance-free - if you have a vehicle that you use occasionally, you can connect such a charger to it in the garage and forget about it.[/quote]


That`s right, there are such chargers, I use one myself. But they do not charge with direct current, on the contrary, they constantly adjust the current to the state of charge. After exceeding 14.4V, they charge only with a very small maintenance current, e.g. 100mA, which does not cause a further increase in voltage. The exception is charging in frost, when the battery has increased resistance. Then the voltage reaches 14.7V.

C`TEK has a very extensive control algorithm, many chargers of this type (including C`TEK) charge with constant current in the main charging phase (the voltage increases, of course, but this is the effect of the battery charging).

The process is described quite well here: http://www.inelco.com.pl/keepower.html

Here from the C`TEK manual: