Re-hydrating the battery modules.

I'm not sure whether it will be successful, but in the past, Honda Civic hybird 2004 were very successful after adding water to the first generation. If the proportion of short-circuiting caused by the damage to the battery core is excluded, almost 100% of the water addition is successful. Looking at the post, many people have also succeeded in adding water to Toyota batteries. I don’t know if your point of view is the result of your experiment, or you can see other people’s failed feedback on the forum. My new battery pack here is very expensive. It would be a very beautiful thing if a simple method can be used to solve the battery problem. It may be a fantasy, but it still makes sense if you experiment.

 

The process of adding water to the Honda Civic Hybrid 2004 was like this. First, use a 1.5mm drill bit to expose 2mm, drill a hole on the top side of the cylindrical battery, add about 5ml of water, and then let it stand for half an hour and add it with an electric soldering iron. Solder is used to seal the holes, no corrosive flux, I use rosin.
Charge to 8.8v at 3a and discharge with a 12v car air pump. The current is about 9a, and the discharge is uniform to 6.95v. The battery capacity without water is very low, and the air pump can only be rotated for about 3 minutes. After adding water, it can range from 17-28 minutes. This is a very big improvement. I think it can fully meet the requirements of 40-80% ecu. In the next 3 months of operation, the electric auxiliary operation will always be there. There is no regular forced charging before, and the long slopes can also be as desired. The battery has almost no operating temperature, the fan is not spinning, and everything is ideal. Honda's vtec engine is also good. The fuel consumption is about 23-26km/l on unobstructed roads at medium speeds. It only needs to be multiplied by 2.35 when converted to mpg. However, the fuel consumption performance in the city is not as good as Pirus. In addition, the short-distance impact of hot cars is sometimes low. At 14.1km/l, that car had a common problem with the cvt gearbox frustrating, so I sold it.

 

这种放电方法可能无法准确测量电池容量，我认为足以比较每个模块的性能。
此外，我购买的15个普锐斯第二代电池模块的测试结果也不错。它可以通过空气泵轻松突破10分钟。一致性也非常好。我充电到约 8.4v 。10 分钟后，有大约 7.07v，这比我 3 个月前更改的 9 个模块的结果要好。比这差了5分钟即便如此，车辆运行良好，没有任何故障灯，油耗约为24-27。KM/升，EV 里程约为 2 公里，车辆运行轻快。下坡时，你显然会感觉比其他汽车更快（我想你踩油门时通常不会走下坡路，而是刹车。如果你刹车，你可以看到刹车灯亮着），电池温度是一点点，高温是50摄氏度左右，但发动机不会被迫连续运行，由于电池的高温。如果这些模块被替换，我认为它可以改善mpg和情绪。一些好的模块确实可以运行空气泵28分钟。对于旧模块，超过 10 分钟是当前的满意度状态。
These figures are the data of the battery in the car, and it can be seen that the v14 module is the weakest.
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The basics of what makes a battery work hasn't changed much in about 100 years.
And ALL of the "tricks" were tried about 90 years ago.

The problem IS:
The electrolyte is made up of several chemicals and water is only one of them.

As the battery ages, there are some unwanted chemical reactions that change some of those chemicals into something else.
Some of the liquid is changed into gas by electrolysis that is vented.
Some of the other chemicals combine into things that are useless.
Some split into things that are useless.

When the cells "dry out" the problem is much more complex than just a loss of water.

But by all means, experiment all that you want.
The experience of others has proven that whatever gains you make will be small and short lived.

 

感谢你的回复。你的详细介绍可能会节省我很多时间。也许弱模块不是由于水分流失造成的。正如你所说，还会有其他细微的变化。我会考虑用一些好的二手模块替换它。再次感谢您的众多解释。

 

Thank you for your reply. Your detailed introduction may save me a lot of time. Maybe the weak module is not caused by the loss of moisture. As you said, there will be other subtle changes. I will consider replacing it with some good second-hand modules. Thank you again for your many explanations.

 

This discharge method may not be able to accurately measure the battery capacity, I think it is enough to compare the performance of each module.
In addition, the test results of 15 Prius second-generation battery modules I bought are also good. It can easily break through 10 minutes with an air pump. The consistency is also very good. I charge to about 8.4v. After 10 minutes, there is about 7.07v, which is better than the result of the 9 modules I changed 3 months ago. It was 5 minutes worse than this. Even so, the vehicle was running well without any malfunction lights, and the fuel consumption was about 24-27. KM/liter, the EV mileage is about 2 kilometers, and the vehicle runs briskly. When going downhill, you will obviously feel faster than other cars (I think you usually do not go downhill when you step on the accelerator, but brake. If you brake, you can see the brake lights are on), the battery temperature is a little bit, high temperature It is about 50 degrees Celsius, but the engine will not be forced to run continuously due to the high temperature of the battery. If these modules are replaced, I think it can improve mpg and mood. Some good modules can indeed run the air pump for 28 minutes. For the old module, more than 10 minutes is the current satisfaction status.

 

I wonder how much rubbish collects in the sump of each cell ...... maybe a drill hole in the centre of the base, a drill hole in each end of the top and a flush out with distilled water before the caustic soda mix is added to refill the cells in each module ......

So I found a dead module, ran it through the band saw and cut the top and bottom off. Each cell had a black residue in the sump. I then flushed each cell through with hot tap water, it came out sort of dark grey cloudy so I'm waiting for that to settle, I'll take a few photos to show what the whole lot looked like.
I've now found a slightly bigger container that Can fit the whole module in, I plan to soak it over night in a caustic soda mix and see what happens ......

T1 Terry

 

The black trash may be the powder that falls off the internal material of the battery. It may affect the capacity of the battery. When cleaning it, lighter action may prevent more powder from falling off. Looking forward to the results of your experiment, I hope you will succeed. This is also very important to me.

 

I have separated one cell from a module .... took a few goes before I actually got one out of the plastic without pulling bus bars that much the broke the connection to their plates.
I've put that in a container of "sodium hydroxide" I poured out of an old 205ltr plastic drum I scoured some time back. Unfortunately there is no indication of the concentration, so it's in a plastic tube with what ever the concentration is, neat. I put some more in a 4ltr plastic ice cream container and put a piece of rusty metal, a piece of the plastic module case with the aluminium sheet attached to the side, and a small square of aluminium from an old street sign. Didn't take long for the square of aluminium to start bubbling away, so I removed that, not much sign on the rusty piece of steel that anything is happening, and the aluminium skin on the plastic piece of the module appears to be bubbling a bit. I'll leave it all over night and see what happens.
The cell read a few milli-volts, so it will be interesting to see what hapens after another wash out and a recharge in a 20% mix of this "sodium hydroxide" and see if there is a result.

T1 Terry

 

After washing, you can first mix the electrolyte with a concentration of 20%. Incomplete grids may also cause the capacity to decrease, but this does not matter, only a few millivolts may improve after charging.

 

Before transferring the 16-cell module, I want to clean up the rust on the positive and negative poles. There are so many black things there that the contact resistance will increase or the power cannot be connected. Is there any way to fix it?

 

Yesterday I cleaned the dirt on the battery module interface. I originally wanted to find a thin and neat and dense copper wire brush to do this work, because I believe that the copper will be softer and will not harm the interface, but unfortunately I can’t find it in the market. To this kind of brush, I used a wire brush instead. After cleaning, I can see that there are many slippery lines on the interface surface. I once wanted to clean it with acidic substances, but it is said that the battery module cannot be dumped, so I used a violent method. , I hope that performance can be guaranteed.

 

Been extra busy working doing lithium off grid installs, it's put these "projects" on the back burner.
With the single cell, I tried a number of different methods to recharge it while it was submerged in a mix of water and sodium hydroxide, just about all resulted in furious bubbling much like an electrolyser (HHO generator) but finally found a slow charge method using a 5W4R7J ceramic wire wound resistor in the negative wire connected across an LFP 100Ah 3.2v nom. cell. Took about 8 hrs till the cell started to produce a fine stream of bubbles. Let the cell sit for 3 days and it is still holding 1.34vdc which would be the equivalent of a module sitting at 8.04v at rest.

When I get a bit more spare time, I'll load test it to see just what capacity it has ..... any idea what amp load I should use considering each cell should be 6.5Ah when new?

T1 Terry

 

Hello John,

Iam a bit of a reader an do like knowlage an where that someone becomes close to facts thats that close ive gotta give that person a nudge to continue of what is ( interested ) ?

 

Apologises for not doing the follow up post for my single cell test. It is so hot and dry here in Mannum South Australia, the KOH in the jar I was doing the testing evaporated leaving the cell dry ..... so I gave up until I have more time to devote to the test.
I have re'hydrated 12 dead modules from an expired traction battery, they were the only ones out of the 28 modules that hadn't leaked through the cases.
They were all at less than 3v, took 60ml to refill them to the point the KOH was running out the bleeder hole in the other end, then a further 10ml the next day after the air bubbles cleared. They have been on a 9v charge @ 6 amps (0.5 amps per module) each day and left to sit over night for 10 days now and have reached the stage of holding 8.6v across the 12 paralleled modules when left over night. So they are now sitting for a week, (busy again) then I'll top up the KOH, charge then again till they hold at least 8.5v over night, then start load testing them individually to see what modules are weak and which ones might recover. I'll repeat the recharge a few times and see if the capacity improves if I don't get at least 5 Ah out of them.

T1 Terry

 

Hi Guys....
I have taken on the task to develop a better means of restoring NiMH cells. It will be a combination of hydration with feedback to determine how much is needed and electro sonics which acoustically assists with loosening /destroying crystalline deposits on battery plates. Kinda like how sound waves destroy/fragment kidney stones.

I have done successful work with electro sonics on lead acid sulphation remediation.
Here is a theoretical reference:
Electro-Sonication - Ultrasonic Electrodes

Here is a DiY lead acid desulfator (I have a fully commercial version with all the bells and whistles, recognized by the BASEL Convention in Switzerland) that employs resonant electro-sonics along with PWM charging and dendrite destruction with up to 800A pulses.

I have run it (with custom voltages) on Prius 'Aqua' Gen 3 NiMH with success that exceeds DC charge cycling.

I am designing gear to expedite smarter NiMH hydration now.

The theory behind this is a dynamic ESR system that is tracking the declining module's internal resistance as water/electrolyte is added. So you know exactly when to stop adding on a second by second basis. This unit will be cheap and made available to all u guys. Hopefully for under $50. I will include a driver for a peristaltic 'insulin type' pump for automated electrolyte dosing and a digital display to show actual module mΩ to help u balance your module pairs & battery packs..

My analysis of the screw leaks on the modules indicate it has to do with the thermal cycling of the steel screws being incompatible with the PP case threading thermal coefficient. The screws expand in all directions when hot and contract when cold, this is degrading the 'tight' plastic case PP threading and is creating progressive leak failure over time. Over-tightening a metal screw on the 2.2mm plastic case wall weakens the case wall threads and amplifies the problem. So, with around 200 screws per battery pack, there's a high probability of a couple leaks down the road.

Solution: Use 6-32 pan head Phillips plastic screws dipped in Gluemasters 'medium viscosity' cyanoacrylic resin, or JB weld plastic epoxy. No thermal expansion movement = no downstream leaks. Engineering thermodynamics.

Also, I am considering addressing Toyota's $ earning strategy of 0.6V module pair differential throwing an ECM error code in Gen 2+ requiring a service call. Clearly this is unnecessary given the Gen1's 1.5V tolerance and appears to be targeting the battery reconditioning effort to enforce a 'buy new' battery approach.
I will look at a plugin module to remediate this via active 'balancing' of the module voltages to restore the 1.5V tolerance. Thus enhancing battery reconditioning outcomes and allowing for less perfectly balanced batteries to become balanced after some use w/o the nuisance error codes.
.
AncelB (33 years Eng. Experience)
[email protected]

 

This all looks wonderfully dangerous, here is my 2 cents.

1- These batteries are DRY inside, they do not have any LIQUID in them, yes, they are WET when you cut them open, but they do not have any liquid sloshing around in them, if that was needed, a lot of liquid, then explain the honda insight battery which is the same chemistry and capacity and volume, and DRY, and made by the same company. I know they are the same capacity, chemistry and physical volume, I replaced my 120 insight cells with 20 prius cells inside the honda pack case.

2- The toyota patent for doing work similar to this involves burning an access hole, replacing adding the needed electrolyte, pressurizing the pack via the access hole to force the electrolyte into the plates, then EVACUATING the excess liquid from the battery. Their goal was to add 9 NINE grams to the weight of the entire battery with missing electrolyte. That is 31.75% of a single ounce (by weight) spread among 6 cells in one battery.

3- The toyota patent then WELDS the hole closed.

4- I am sure you get FANTASTIC results when you fill that cell to the top of plate with liquid lol.

 

Send your dollars out of the country and hope for the best.

 

I won't be doing your item #4. I am designing an electronic unit to indicate exactly how much liquid is needed to restore OEM internal resistance spec. So no guess work and no overfilling to choke the vent.