DIY Solutions to Honda Hybrid Battery Problems (Insight, Civic, IMA)

[Artric]

By the way, I'm not holding my secrets. If anyone wants to jump in and make one themselves, feel free to contact me and I'll give you all the help I can!

[discovery]

Originally Posted by Artric

By the way, I'm not holding my secrets. If anyone wants to jump in and make one themselves, feel free to contact me and I'll give you all the help I can!

At what Voltage is set the charger? Is it at 144V or above 144V? How difficult is to build one?

[Artric]

Originally Posted by discovery

At what Voltage is set the charger? Is it at 144V or above 144V? How difficult is to build one?

Assuming you're talking about a G1 Insight or G1 Civic Hybrid, 144v is only the nominal voltage. When your pack is at that level, you're pretty much empty (in terms of what the car will let you use). A full battery is usually in the high 160's to low 170's (depending on condition and temperature).

The chargers have a variable set point which marks the highest that it will charge to. I usually set it around 177, because that's higher than I've seen a pack go. It doesn't charge at this rate, but rather the current voltage of the battery. A constant current/variable voltage power supply is used to give it a "swing" of 39v. Therefore, at a max of 177, it will charge as low as 138v (which is actually 1.5v higher than what is given to the battery, as that is lost from diodes).

It's really not too difficult to put together. I just depends on how fancy you want to get with it. For me, that entails finding dead power supplies, gutting the cases, measuring, drilling, testing fans, etc. They work great for me as I can sometimes get them for free, or just a few bucks, they're usually just the right size, and they include a standard AC power outlet, fan, and sometimes a power switch.

But you can be as simple as affixing them to a piece of wood, like you see here: MIMA Honda Insight Modified Integrated Motor Assist - Building a hybrid car grid charger

Wiring is pretty simple - you run AC power to three 48v power supplies (Mean Well RS-25-48), one 12v power supply (Mean Well RS-25-12) and one 350ma constant current power supply (LPC-20-350), with a fuse for protection (use 10A, on the following diagram it says 1A, which will blow constantly). Then you wire all of the power supplies, except for the 12v one, in series, and you've got your two outputs for charging - just set the max voltage using a screwdriver on the side of the units. The 12v is there to power your pack fan and anything else you might want to use it for.

Those are four wires you need to get from the charger into the battery box and connected to the battery and fan. For the fan, you just need to splice into its power wires. For the battery, you need to connect to the top negative connection on the battery with a ring terminal, and lower down on the side of the battery (at the precharge resistor) for positive, using a piggyback spade connector. In addition, you'll need to use diodes here to make sure that charge only flows into the battery and not back out to you or the power supplies. You don't want to get shocked! You also need to put a small DC fuse in place on the positive side (in line with the diode, so you'll need to solder, as well as crimp for the connections).

That would give you a direct connection, but if you want to be more fancy, you can use molex connectors, bullet connectors or a number of other options.

You can see the diagram for the grid charger with pictures here: MIMA Honda Insight Modified Integrated Motor Assist - Grid charger/Balancer 1

And you can see info on the components and how I install wiring here from my walkthrough: 7 - Power Off | Flickr - Photo Sharing!

Good luck!

[discovery]

Originally Posted by Artric

The chargers have a variable set point which marks the highest that it will charge to. I usually set it around 177, because that's higher than I've seen a pack go. It doesn't charge at this rate, but rather the current voltage of the battery. A constant current/variable voltage power supply is used to give it a "swing" of 39v. Therefore, at a max of 177, it will charge as low as 138v (which is actually 1.5v higher than what is given to the battery, as that is lost from diodes).

Thanks for the good info.

Once the HV Battery reaches 177V after charging it for many hours, for how long do you top it off? Also, what is DC fuse?

Thank you

[Artric]

It doesn't generally charge to 177v. It usually maxes out in the high 160's or low 170's. The idea of setting it to 177 is so that it will not stop charging.

Once each cell starts to top off, it releases a small amount of heat. At 350ma, this is minimal. Some will reach the top before the others, which is necessary to bring them all up to the same charge.

To gauge when the pack is finished, you'll see that the voltage will stop rising, then slightly drop. At that point, you're good to go. Monitor the charge throughout with a basic DC multimeter. Note also that if you're charging daily, you don't need to do this type of a balancing charge every time.

If you can somehow get your SOC down to 30% (by riding the gas in the hills or using MIMA), it'll take about 9.5 hours to reach 80% (which is as high as the car normally charges). Another 3:45, approximately, will give you the final 20% state of charge, which is extra that what the car will normally supply.

And the DC fuse is a simple fuse inbetween the charger and the positive charge input on the battery rated for 200v DC to make sure that no surge happens that can destroy the battery. I usually solder them in with the diode (which is placed at the battery connections to ensure that no current flows out from the battery and hurts someone).

Hope that helps!

[discovery]

Originally Posted by Artric

It doesn't generally charge to 177v. It usually maxes out in the high 160's or low 170's. The idea of setting it to 177 is so that it will not stop charging.

Once each cell starts to top off, it releases a small amount of heat. At 350ma, this is minimal. Some will reach the top before the others, which is necessary to bring them all up to the same charge.

To gauge when the pack is finished, you'll see that the voltage will stop rising, then slightly drop. At that point, you're good to go. Monitor the charge throughout with a basic DC multimeter. Note also that if you're charging daily, you don't need to do this type of a balancing charge every time.

If you can somehow get your SOC down to 30% (by riding the gas in the hills or using MIMA), it'll take about 9.5 hours to reach 80% (which is as high as the car normally charges). Another 3:45, approximately, will give you the final 20% state of charge, which is extra that what the car will normally supply.

And the DC fuse is a simple fuse inbetween the charger and the positive charge input on the battery rated for 200v DC to make sure that no surge happens that can destroy the battery. I usually solder them in with the diode (which is placed at the battery connections to ensure that no current flows out from the battery and hurts someone).

Hope that helps!

Yes need, thanks very good info.

[Artric]

::thumbsup:: Found how you might be able to get parts cheaper, too!

[CindyPA]

Robert,

I have an 03 Civic hybrid with a dying IMA battery. I've talked with Ron at hybridbatteryrepair.com, and checked out other options, including buying a salvage battery. My very competent and trustworthy mechanic wants to help, but isn't willing to venture into this area, so I'm probably going to end up paying the dealer's price. Two questions, though.

You say "You can repair your own IMA battery for $100-350 including equipment and replacement cells, instead of paying someone $1000 to do it for you, or dropping $3000 at the dealership." I would be happy to pay someone $1,000 to do it as long as I knew they were reliable. Hybridbatteryrepair.com is mentioned all over the place online, but I've seen few testimonials. Do you know of anyone else?

And do you know if IMA prices vary by dealer? Driving a distance would be worth saving some money. Thanks.

Cindy

[Formula413]

How many miles are on your Civic hybrid? I have an '03 also, bought about a year and a half ago. At around 86,000 miles my IMA light came on, and the code in the computer indicated battery overheating. The battery also seems to have fairly limited capacity, although I can't say how much worse than when it was new since I bought it used. I took it to the local Honda dealer just to see what they would say, since the IMA components are warrantied for 80,000 miles. The service rep told me that if the code comes back than it would be very likely that Honda would be willing to work with me on the replacement cost of the battery. He seemed to suggest that I could expect to pay half or possibly less of the going rate for battery replacement. I doubt he would say that if he didn't think that it is very likely Honda would be willing to do this. I would start by talking to your local Honda dealer or dealers depending on your location.

Just out of curiosity how many miles on your Civic? And can you describe in detail how your battery is performing as of now?

[CindyPA]

Formula 413, my car has around 105K miles on it. The emission control light has been going on and off sporadically for several years, and finally the IMA light came on. That's when I went to the dealer and got three codes: P1601, P1447, and P1420 (for the catalytic converter). My mpg is lower than it used to be, but I haven't paid attention to the charging levels, etc.

Honda probably would work with you, based on all the online chatter about how poorly some of their batteries perform. Mine's long out of warranty. Good luck with it!

Cindy