🔋⚙️ Recharging a calcium battery Ca-Ca - master class

Today is 11/27/21. Winter is coming, which means it's time to pay attention to the battery. Moreover, in my case there are a couple of reasons why I have to recharge the battery more often than I could do. These reasons are discussed below.

"Patient" - calcium battery, cheap, 60, operated for two years. There were two deep discharges, which were eliminated promptly. But the battery capacity, nevertheless, is no longer 60 Ah (although it is quite possible that it did not have so much in the new one either - I somehow did not check it right after the purchase). Checked capacity last year. I counted about 45 Ah.

What is the purpose of recharging, what and how will I charge, the initial state and the key stages of the procedure - see below.

Goals and action plan

I periodically recharge the battery with a stationary charger for the following reasons:

1. The car is rarely used - since any car battery is slowly discharged (leakage current, self-discharge, devices in standby mode), a deep discharge may occur during long periods of inactivity. This is harmful for the battery, plus in winter you can find yourself in a situation where you urgently need to go, but the starter does not turn. This is my case, since I go every two or three days. Especially in winter.
2. The car travels little - and the battery does not have time to recover from the generator. Also my case, since I don’t need to travel far. My most frequent route is 10-15 km.
3. Low on-board voltage - I have it 14.0-14.1 V. Considering short trips, the battery is not systematically fully charged from the generator. In my case, this is not a malfunction, but a feature of the relay-regulator. It says 14 V, which is the norm for a thirty-year-old foreign car. You can change. The price of the issue is only 6 bucks, but it's all too lazy. Well, as usual.

For the combination of these three reasons, I have to "drive" the battery with stationary charging once every couple of months in the summer, and much more often in the winter.

The goals are to prevent deep discharges that threaten a sharp reduction in battery life and a sudden inability to start the engine when (according to the law of meanness) it is necessary urgently.

The action plan has been developed over the years:

1. I leave the battery to stand alone for at least 8-12 hours. It is not necessary to do this, in principle. But I do this in order to be able to correctly assess the degree of charge with a simple multimeter.
2. I remove one terminal - it would be better, of course, to completely remove the battery and take it to a warmer place for recharging, but my car has such a design that you can’t stretch the battery without dancing with a tambourine. Yes, and there is no warm place. In a house where there are children, it is not good to do this.
3. Assessment of the initial charge level - with a multimeter and by the indicator on the battery (sometimes I measure the density with a hydrometer).
4. I don’t unscrew the plugs, because I always charge with small currents, the battery is calcium, and it will “boil” only at the last stage of recharging.
5. I connect and configure the memory.
6. Periodically I control the process, since the memory is self-made and far from automatic.
7. I charge so that the charge voltage does not exceed 14.4-14.5 V.
8. I charge until, at the specified voltage, the charge current drops to 0.3 A.
9. I "boil" a battery with a voltage of 15.5-16.1 V in order to equalize the density of the electrolyte (I do not always do this).
10. The next day, with a multimeter or hydrometer, I evaluate what happened.

To understand why I do this, read (if you haven't already read) my material on charging calcium batteries. I believe that my methods are correct, since calcium batteries serve me for a long time, despite the very unfavorable operating conditions. Actually, on this machine, this is the second battery. The first was bought along with the car, and died at the age of 11. The current one worked for two winters, and I plan not to change it for at least another three years. Five years for the cheapest thing that was in the store, it still takes some effort.

Training

The photo shows how the niche for the battery is arranged. There is a partition of the engine compartment in front, and a decorative grille at the top-rear, through which the stove draws air from the street. If you don't remove it, you'll drain the battery. Either they used to be smaller in size, or I misunderstood something. Twisting, tilting - there is also nowhere, and the power wires interfere.

First of all, I remove the clamp. It is more convenient to disconnect the negative one, and I do it. Further, it is desirable to at least slightly clean the battery case from dirt, as it can cause additional self-discharge. The terminals themselves are free of oxides and sulfates (what's the difference and why I don't have this muck - see here).

Assessment of the initial charge level of a calcium battery

Since the battery "rested" for almost 24 hours, you can evaluate how charged it is with a multimeter and this plate.

I measure.

The leakage current is normal, but the charge level, as expected, is low. Should be at least 60%. If for a long time it is below 60%, then sulfation begins. And desulfation is another hassle.

What and how will I recharge?

To charge my battery (and many other things) I use a homemade charger. It is a transformer (linear) power supply with the ability to adjust the voltage in the range of 1-20 V. The case is made of a computer PSU. Voltmeter-ammeter Chinese. The inside is extremely simple. Transformer, diode bridge, a pair of input and output capacitors, a pair of transistors, forced cooling. It produces relatively modest currents - no more than 3A. Since I'm usually not in a hurry, I have enough.

If someone is interested in the internal structure, diagram and features of this source, contact me in any of the ways available on the Auto without SRT website, I will share it. If there are several applicants, I will prepare a full-fledged review material. Actually, here he is.

Since the voltage at the terminals is 12.2 V, I set it to 13.2 V on the memory. From experience, this is just the thing.

I throw crocodiles on the terminals.

Then I proceed as follows. At the first stage, I regulate the maximum current for this memory by voltage. Usually no more than 2.5 A, so as not to fry at the maximum. Then I wait until the voltage rises to 14.4 V. Then it remains only to periodically reset the voltage (keep it at the same level), and wait until the charge current drops to 0.3 A.

Photo report of the charging process

The voltage at this current and this level of battery charge rose quite quickly. Previously, it felt like it took more time. This means that the capacity of the battery is steadily depleted. It takes less and less time to recharge from 50%. I continue.

Now I'm waiting until it drops to 0.3 A and then I'll start to "boil". By the way, up to this point, the indicator on the battery has not changed color - red despite the fact that the battery is clearly well recharged. This phenomenon is due to the fact that the indicator "measures" the density of the electrolyte in the upper layers, above the plates. There, no reaction takes place, since the currents are small, and the battery does not boil. It is in order to even out the density of the electrolyte in the cells that the manufacturer himself in the instructions recommends that at the last stage of the charge "drive" 40 minutes of batteries with a voltage of up to 16.1 V.

As I said above, I do not always do this. If a trip is expected immediately after recharging, then the electrolyte is mixed and so, due to our "smooth" roads and moderately destroy chassis. After the first trip, the indicator usually turns green. But in this case we will "boil". Usually 40 minutes is not required. Enough minutes 10-15, and it turns green. You can verify all this with the help of a hydrometer. I used to do that. But now the device has crashed, and I don’t see much point in measuring something, the result of which is always the same (as it turned out later - I was wrong). You should bother with a hydrometer if you have a discrepancy in the density of the electrolyte in banks. But that's another story.

We are waiting for 0.3 A.

By the way, since the battery is calcium, the recharging process could be significantly accelerated. To do this, the voltage rises to 14.8-14.9 V, which is practically harmless for batteries of this type. However, I am a supporter of as slow charges as possible. I am convinced that the lower currents and voltages to charge any battery, the more energy it accumulates. Repeatedly convinced of this, not only on the example of car batteries. All gadgets - phone, tablet, camera, power bank - I try to charge not through the network adapter that comes with the kit, but through the USB of my laptop. Adapters charge all this junk with currents from 1 to 2 amperes, and USB is only 0.5 A or 500 mA. As a result, gadgets charge much longer, but there are a number of advantages.

First, batteries never overheat. Secondly, they charge more "densely", and then, accordingly, "hold the charge" noticeably longer than after the mains adapter. Thirdly, since the batteries do not heat up and are not raped by high currents, they always last longer for me - the capacity usually begins to be lost after 3-4 years of intensive use. This is despite the fact that, on average, smartphone batteries in people begin to die in six months or a year. True, I also try to maintain the charge level in gadgets in the region of 40-80%, that is, I do not allow frequent deep discharges and full charges. So, if you have extra time to wait until it is charged with small currents, take note. The technology really works. I have been using for over 10 years.

The "boiling" step can be replaced by two methods. The first is to do nothing, just ride on rough roads, which is not difficult in our conditions. The second method is a little tricky, and consists in forcibly mixing the electrolyte in the cell near the indicator with some non-conductive object - for example, a coffee stirring stick. You can also "stir up" the electrolyte layers with a syringe or the same hydrometer. Such is the arrangement of modern batteries - the main process takes place in envelopes near the plates, while the density of the electrolyte must be forcibly equalized above the plates. Today there are already batteries (used on trucks, and maybe already for cars), the device of which provides for special things that help mix the electrolyte in the banks when the car is moving.

That's all recharging a calcium car battery before winter. It remains only to wait 8-12 hours to check with a multimeter what happened. The specified time the battery must "rest", otherwise the measurements will be incorrect. In order not to wait, the charge level can be estimated by the indicator or by the density of the electrolyte with a hydrometer (hydrometer vs refractometer). Mine broke, so I'm waiting. Moreover, there is no need to go anywhere yet, which means that the battery will "rest" for almost a day. A photo of measuring the voltage of a fully charged Ca-Ca battery will be later.

VIDEO: about recharging a car battery