Reconditioning Questions

Your reconditioning a non-stock battery HV battery is this correct The factory battery I don't think was cinderrical they're flat plates so this is an aftermarket type battery is this the project lithium or something that was bought on Alibaba or something like that?

 

unfortunately, there isn't one go to source. but there are a bunch of threads here, and probably some youtube videos as well.

 

So you have a lot of space left over under the battery housing or there's a bunch of plastic mounts that take up all the space in the case? Where did you get this set up I guess is my question?

 

Your load testing & using Tenergy t180 is for a reconditioning that includes a rebuild (replacing bad modules). But you don't need to bother with any of that if you're just reconditioning, which is ideal because finding cylindrical modules that match your pack's modules is not easy. As in you want to send a 1/4amp to 1/2 amp 250v signal to the pack while running the battery fan... Then use a couple lightbulbs wired in series to discharge. The owner's manuals at hybridautomotive.com is a good resource for using the correct bulbs at each stage of discharge. There's lots of grid charger designs you can choose from. Here's the thread we created a while back: Build Hybrid Battery Maintenance Gear For Under $100 | PriusChat

 

Without having to read all that. Are they building a charger that charges the whole pack at once? Or is this a module charger It looks like it is a pack charger. Which is what would interest me a hundred bucks seems interesting. As other ones on the market even put together by other people and look to be close to $300 in parts like the Venice hybrid system discharger and charger.

 

And how did this come to be you just saw them on a site and bought them or is it a kit type thing? I've only seen pics on Ali baba . I think now they've lithium similar to nexcel that sort of thing.

 

I wanted to try these years ago but there was no local support or seeming interest at the time. And at the time this type of thing was costing $1,800 if I'm not mistaken or similar and then when it came time for me to really need a battery The dealer new was on like 14 00 so of course I went with the dealer new rather than something nobody knew at the time It was just in pictures on a site . And costly and different looking.

 

Apologies for delayed reply... If you're going to recondition modules it's going to take really long using the tiny 20 watt resistor in your t180 and you'd be better off using a standard halogen headlight bulb, which is usually about 50w and 12v. And because this bulb is used for load testing 8volt modules and your modules are 16volts you might want to use two bulbs, or measure discharge for 4 minutes under that load rather than 2 minutes.

Only other thing you want to do is build a spreadsheet of all voltages when you pull the pack, then load testing as you start reconditioning, then after 3 increasingly deeper discharges once you're all charged up it's wise to let the fully charge pack sit for a few days or longer so you can add self-discharge numbers to your spread sheet. All this data will be super helpful in the future when you have to diagnose a failing module.

 

Terminology:

• Cell: 1.2 volt (nominal) unit. Can't change this: NiMH chemistry determines it.
• Module: in the original, six cells (7.2 volts nominal). Original has 28 of these. The cylindrical version is double-wide and made of twelve cells, 14.4 volts (equivalent of two original modules).
• Block: The unit of monitoring by the battery ECU. There are 14 blocks, no matter what style of battery is used. In the original, each block is two modules. In the cylindrical replacement, each module is its own block. A block is always 14.4 volts nominal.

 

Sure hope you have a fan going to keep them from running hot!

Also a thermal camera can find cells that are running hot before they fail.

As for discharge numbers that looks fairly good, but your discharge voltages don't go low enough in my opinion. I remember back in 2018 I went to visit Joe at 2nd life battery, who has $30K in lab-grade rebuilding gear and is also a professor who teaches hybrid and electric car repair at his local college. I told him that Hybrid Automotive's electrical engineer recommended increasingly deeper discharges and in the 3rd round instead of dropping each module to 12v per block, they recommend taking it down to 0.1volt per cell or 1.2v per block.

Joe laughed at me when I said that... But then 4 years later we were texting about other things and he mentioned that he discharged down below 6v per module by accident and decided to study the benefits of it and realized it's better than what he was doing. So his initial laugh has now turned into leaning more towards agreement.

Meanwhile the folks over at Hybrid Automotive kept getting customers who were following their numbers and getting failed modules. And while for us rebuilders, the more bad ones you can find the better, that's not ideal for a consumer product that is very expensive. So Hybrid Automotive have boosted the numbers of the 3rd round of discharge several times. Here's there current numbers:

 

The most heating will happen on the recharge after your deepest discharge... If you know anyone who does home inspections, they have a thermal camera and I highly recommend monitoring for heat with one of those.

As for using the charger to measure mah, it's a very crude measuring tool that I don't trust and don't use. Some feel comfortable with it but not me because NiMH charge very inefficiently and if you aren't spending tens of thousands on lab-grad gear, you're only getting a measure of charge that's been sent, not the charge that's been received, especially during the balancing phase when the full cells that are waiting for the not full cells to catch up aren't receiving additional charge, just dissipating their charge as heat, which is why at that stage you need to keep the amperage super low or you'll cook them into failure.