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?