Charging hybrid battery with RC Charger

I'm not quite sure I understand your concern. I "refreshed" (refurbished, rebuilt) the HV pack in my Gen2 after reading the ginormous thread about "individual module replacement". My take on it was that you want to gently overcharge the module in order to equalize all the cells. The weaker cells are given more time to reach full capacity while the fully charged cells bleed off the excess power as heat. Then you discharge and charge- which helps restore diminished capacity.

I went with around 2 amp discharge and charge, 3 cycles, down to 7V, then, 6.5V, then 6V. Charge was to first 7000 then 7500mAh- deltaV disabled. If discharge capacity didn't improve much then I did more cycles, going down to 5V then 4V if needed. Measured discharge capacity of all modules was 5.5 to 6.2 Ah before reassembly.

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The SkyRC processor is calibrated to deal with smaller modules than what we work on, so ignore that max charge warning. As for settings I charge at 4.4amps and use 50W 12v halogen bulbs to discharge because it's way faster and you get a visual indication of the discharge that you can see out of the corner of your eye. As for discharge limit, 1st round down to 5v, 2nd round down to 3v, and 3rd round down below 1v.

The notion of doing all 3 discharges only to 6v would be fine if you had tens of thousands of dollars of lab grade equipment like major rebuilders have, but that doesn't work for DIY.

 

Slight thread hijack:

A quick question for you all. In this discussion, you're talking about disassembling the battery and charging individual modules, correct?

 

yes... There's 28 individual modules strung together and each module is made up of six standard ~1.2volt cells strung together to make a ~8volt module...

 

Oh, I see what you're saying...

And again, as I already said... we're using cheap equipment so the amount of energy that the charger is sending is wildly different than the amount of energy that is actually veririfed as being stored in the battery so it's worthless to try measure milliamp hours. The more you practice, the more you'll be able to use the voltage reading to estimate how fully charged it is.

But more important, there's a bunch of red flags in what you wrote:

-- If a module balloons it can't be fixed, as they aren't designed to be charged when they are not compressed together on the mounting rack.

-- These are 6800mah modules and you only discharged them down to 6v and you're trying to force 7K to 9Kmah in them? That will ruin them!

-- NiMH batteries are damaged if they're overcharged, which is why once a pack is charged the balancing stage, which overcharges them, is done at a super low amperage.

 

I mentioned that I had DISABLED delta V- the battery module mega thread had several posts about people having problems with the delta V function on various chargers, esp at lower charge rates. So when I used my charger, it would only do a single discharge / charge cycle up to the mAh limit that I had set then it would terminate- ie, it would discharge down to 7V or whatever then charge the full 7500mAh then end. Oh well. I had to manually reset each cycle. All modules were clamped in the battery frame and had fan blowing through them continuously. At 2A charge, ballooning was never an issue.

 

Sounds like you're still destroying your battery modules... Losing the charge you're sending to a module to heat is not too damaging when you're only charging at 1/4 amp... But once you get into higher amps for too long you're just destroying stuff. As I already said these modules can only hold 6800mah and I do that in two stages at 4 amps to let everything cool down so I don't destroy what I'm trying to improve.

What you're doing is kinda like putting a turkey in an oven at 1500 degrees when the cooking instructions tell you to cook it at 325 degrees.

 

Yea... It's incredibly tempting to speed the process up... And if you have $20K in lab grade electronic gear there's very little limit to how fast you can go. I'm especially guilty of speeding up discharging with light bulbs using a 12v - 50w and 12v - 20w in parallel, which is super fast when modules are at full charge but potentially damaging below 5v.

 

Hey, good morning am looking into leaning more about hybrid battery reconditioning and I have my hybrid battery pack removed of the car, first this batteries are not going back to the car because I installed a new kit from newpriusbatteries.com so I need to figure how to compress the batteries to work on them I basically want to cycle the modules (I did it with the prolong deluxe but I got not information about capacity with the prolong) so I want to play with one of the RC charger so I can work on the modules, they are out I need to compress them with probably wood and clamps and find out more information that prolong didn’t give me (modules capacity) so looking for a recommendation on a good rc charger, it can be for one module at the time since doing this just to make sure modules are good before attempt to sell them, any help with be appreciated!

 

One more question, when load testing with a car headlight bulb beside finding modules no matching the others ones how much voltage drop in 2 minutes will qualify a module as not good.

 

Yes... and buying a whole bank of multi testers and light bulbs allows you to race modules against each other and find the ones that discharge too fast. And in general until you get to the third round of discharging/reconditioning the modules act kinda crazy so it's better to build a spreadsheet and look at all of the data when you're done. Also a thermal camera is fastest way to find modules prone to overheat and tiny balloons over the module vents helps you not only keep the air in your work space clean, but helps you find bad modules.

Lastly for charging, the new Skyrc has lots more power and a faster processor, but still too primitive to accurately measure amp-hour capacity as NiMH loses 30% and sometimes more of the charge you send it to heat. iMAX B6 V2 Charger

 

Am trying to learn the capacity of the modules on my pack so I order replacement modules (3) from 2ndlifebatteriesllc (ebay certified hybrid technician) and this are the result of the modules I received from him after 2 minutes load test with the car headlight bulb:

8.30- 7.56 different 0.74
8.27- 7.53 different 0.74
8.29- 7.54 different 0.75

Test was done several hours after charging and balancing the pack but pack still was warm at the time of the load testing

My old modules range from the lowest 0.70 to the highest 0.94 with one module that like to heat more than the others so my guess everything around 0.30 from the replacement modules can be considered good since the replacement modules I have I got it from a professional hybrid technician, please correct me if am wrong I really don’t want sell my old modules if they are bad, trying to make sure what is good it’s really good.

 

I am also looking for an RC charger to cycle charge some Prius modules, that will reliably detect delta V. I watched some Youtubes that concluded the HTRC C240 and the Imax B6 chargers were not able to reliably detect Delta V on Prius modules.

The two I am considering:

Tenergy T180 100W 10A on Amazon Prime for $77
and
EV-Peak A1 100W 10A $50 (on Amazon with $10 coupon)

Can anyone comment on these chargers or recommend another? I have very little charger knowledge beyond YouTube/Googling.

I bought some battery modules and relays that were supposed to be from a 2010, but the relays had gen 2 part numbers.
How can I tell the difference between Gen 2 and Gen 3 battery modules?

All the modules read 8.4V (no load). Encouraging that they were all consistent, but sounds a bit high (float?)

 

Look at the picture am uploading that may answer you question for the module date.

 

Ok, I ordered same one you recommended so now since you have experience with it what are the settings I should use for reconditioning the modules, my goal here is to find which modules are good and which ones are trash and at the end I can sell the modules in good shape, they not going back to my car because I installed a newpriusbatteries hybrid battery kit 3 days ago, so doing this to give this modules a second life lol, by the way thank you for you time!