DIY Grid Reconditioning Charger

there is something that doesn't make sense. my understanding is:
1. light bulbs in series don't add up. the reason prolong uses two light bulbs is just to protect the circuit. one bulb alone could explode by itself. so I am not sure how you are reaching the 200 watts without a 200 watts bulb? maybe wiring in parallel which I don't think is recommended?
2. light bulbs in the USA are rated for 120 volts so that is another reason we need two light bulbs to closely match the hybrid capacity. for europeans who have light bulbs rated for 220 volts, you only need one light bulb. right?
3. don't you guys use heat lamps in bathrooms in europe? those bulbs are usually rated at 200 watts and higher.

Edu4prius I was in valencia way back in 1998.... beautiful...

 

The thing about doubling the bulbs is something I found confusing from Prolong's guide at first.
But, remembering Watts's law, it makes total sense. Watt's formula states that Power = Current x Voltage.
Since we are aiming to a harmless discharge current (starting at ~1,7A and finishing at ~0,25A), we can rephrase the formula as Current = Power / Voltage. Then, bulbs for higher voltage need to be proportionally more powerful.

That makes that European bulbs need to be ~2x times more powerful to keep the proper current at 240V. Since 400W bulbs are not easy to find (if findable), you can do as Abarnabe and join in parallel as many of them as you need to reach the suggested 400W. If you don't get up to 400W your discharge will be slower but safe, if you get above 400W your discharge will be faster, but you'll be out of the safe zone and may damage your battery.

The reason why American bulbs have to be put in series and not in parallel is that voltage is additive, so to match the ~230V from the battery you need join two bulbs that work at 110V to get a system that works at 220V. Connecting a 110V bulb to a 230V battery would definitely blow the bulb.

Hope this clarifies things (and I hope to not be wrong about electricity laws )

@tri4all, I'm glad you enjoyed this place!

 

Hey @Abarnabe, I ended up buying a very similar LED driver from MeanWell, mine is HLG-80H-C350AB (notice the additional B at the end). It's almost the same but it can regulate dimming. I actually don't care about that feature, but it was the only available model I could find in Spanish online shops . In addition, I made my own harness based in Prolong's one but a lot less elegant and using standard connectors - I hope to post a new thread with pics soon.

I also got 8 diodes like the ones you used (1n4007), soldered them in a row and hooked them in the middle of the positive wire. The thing is that, around a minute after I started to charge the battery I noticed they became too hot, so I removed them because I was scared of messing up. So now I'm charging the battery at 257V since I thought it would be less harmful than the diode thing.

Do your diodes get so hot? If not, what could be failing?

 

In a REALLY STUPID error, I mixed positive and negative wires and I blown the LED driver (a.k.a. grid charger).
I tried to open it to see if there was a fuse that could be replaced, but instead I found a grey block of some kind of silicone that seems to serve as dust and moisture isolation. I tried to remove it to see what kind of stuff it contained and I found some electronics that are not easy to understand or fix for me, so I ended up ordering a new one. This time the model is HLG-80H-C350A.
I guess the diodes would have avoided this mistake...

Just to illustrate the grey silicone thing, here I attach a picture taken after a bit of carving.

 

I have NO COMMENT on this matter!

 

Hope people are still following this thread.

Looking at the specification of the LED driver used by @Abarnabe, I found that the constant current mode is valid only when its output voltage is between 128V and 257V. When the output voltage drops below 128V, the driver enters a "Hiccup Protection" mode, turning on / off automatically until the voltage catches up. Has anyone observed their charger behaves weirdly at the early stage of charging after the battery is deeply discharged?

 

I would like to thank Abarnabe very much and let those of you who are wondering whether to give it a try know that I successfully used the Meanwell to recondition and rebalance my 2008 Gen2 hv battery following the dreaded triangle of death.

This thread and other priuschat hv battery threads were key for me.

I first tried a 3-cycle rebalance in-car, but got the triangle again almost immediately.

I pulled the hv battery from the car, load tested each individual blade with the headlight bulb tester, and replaced one obviously bad blade. Then I rebalanced the pack with its “new” blade.

I added a voltage divider circuit (rather than diodes) to get the maximum charging voltage of the Meanwell unit down to 248V, but I don’t know that this is really necessary at 350 milliamperes.

What is necessary is an inline fuse. The electric cord I adapted from a battery charger cable to connect to the hv battery terminals just happened to have a 15 amp fuse already built into it. That fuse saved the wires and electronics when I neglected to unplug the main switch once and got two VOM test leads too close together, and they arced.

It was so much current it destroyed the fuse holder, but the fuse blew so fast nothing else was harmed. I replaced the fuse holder, and would not be without it.

The battery charger cable I used was the kind with flat two-prong connectors, and I used white-out to mark the (+) and (-) sides of the connector starting from the hv battery. Those markings helped me to think through and make sure that whatever I connected to that connector - the Meanwell or the voltage divider or the lightbulb discharger - was itself correctly polarized, and I marked their mating connectors as well. (I bought a bag of foot-long cables with mating 2-prong flat connectors to use to wire various things up.)

I made and used the manual 2-bulb lightbulb discharger, and I managed to over-discharge the pack out of the car on two separate occasions; once by quite a bit.

I share that because the pack came back from those insults. So don’t despair if it happens to you. Just do another multi-cycle rebalance, and monitor the pack’s behavior.

I cleaned the corrosion off the battery pack lugs on one side of the hv battery, but replaced the entire harness with all the sensor wires on the other side. I could not see myself successfully cleaning those of corrosion without damaging them, possibly without realizing it, and then putting everything back together and having no idea what had gone wrong.

Per Abarnabe, I used a 12V charger to power the car fan (which I also cleaned as many recommend) when charging in-car. I wired the charger into the fan connector, but did not otherwise alter the car’s own fan control, plugged into that same connector.

I was surprised that even with constant power from the charger, the fan still cycled on and off during in-car charging (it would run about a minute, then turn off for 30 seconds to a minute, then back on for another minute or so), but it seemed to be sufficient cooling for 350mA charging, in winter. I assume the cycling stemmed from the car’s fan control circuit.

When I charged the battery out of the car, I ran an AC-powered furnace blower constantly, hooking it up with a vacuum cleaner hose to the hv battery’s blower duct (the one at the top of the battery pack), which I also took out of the car and used for that purpose.

I think that when I rebalance in-car again, I will try to figure out a way to use the AC blower too, perhaps through the car fan’s intake (the intake by the rear passenger-side door). I will still use the car fan as well.

I reinstalled the battery in the car about a month ago now, and it is performing very well - no red triangles! I monitor it using the Dr. Prius app and plan to rebalance quarterly to semi-annually.

It took me a long time to do all this and I was fortunate to have another vehicle to use while the Prius was out of commission. I learned a lot, made more than my share of mistakes, saved a goodly amount of cash, and kept the Prius, which my wife dearly loves, in service.

Thanks again, Abarnabe, and thanks to the many others of you who have posted so much informative and insightful info to priuschat.

 

Nice write-up!

 

That's just potting on the switch mode transformer. Sometimes they sing a bit that dampens the noise.

Your on the primary side. Look at the other end that's the output side. That's where the excitement took place.