I'm in the process of replacing my IMA battery, and have been unable to remove the grounding bolt of all things. The metal the nut is attached to is very flimsy and the nut has a proprietary non-symmetrical shape that's just above 10mm and below 11mm. This 12 year old bolt has never been removed before and is a bit seized on there. I've already tried WD40 and just applied some bicycle chain lubcricant/cleaner and am waiting for that to penetrate.

Any suggestions for how I can remove this bolt? Kind of dead in the water here without being able to remove this grounding bolt.

 

2004 HCH? I'm wracking my brain trying to think of what you might be talking about.

You mention a bolt, then a nut, and there's nothing proprietary about any of the bolts/nuts used to pull a HCH1 pack.

Care to look at these pictures and give me a clue:

https://hybridautomotive.com/pages/install-c1

 

Thanks for the quick reply. It's the bolt in the middle of this photo.

I was able to figure it out. The bracket holding the grounding nut is quite flimsy and bends when trying to loosen the bolt. If the bolt has never been removed as in the case of my 2004, the bracket would probably break off if you brute force it. I ended up removing the box the nut is welded to, turning the whole box around and securing the nut with slip joint pliers to provide the leverage required to break the bolt loose. I'll post some photos later.

Side topic, I believe I read you created a 350mA trickle grid charger a while back. Do you happen to have a post somewhere of your build with materials and instructions?

 

Scratch that, I see the grid charger build is in your sig, thanks a bunch!

 

Wow. It's been a long time since I've been in an HCH1 IPU. I didn't remember that one at all. Glad you got it sorted.

The HCH requires a PWM signal to properly drive the IMA fan. Under no circumstances should you grid charge without running the fan. With a very strong 12V PSU (10A), you can short the PWM wire to ground and run the fan at full blast.

 

Thanks for your hints. Just got the car last week, and trying to get it whipped into shape to pass smog. If I grid charge, I'll be doing it outside the car with external fan for now. But I will want to rig it up so I can grid charge the replacement pack in situ.

Also trying to find out all the different options for battery pack revival and management. I have a used packed on the way from 2005 donor car with 65k miles that will hopefully be plug and play. Looking like I may need a grid charger to prolong this pack as well as revive the original pack.

Was also looking at getting bare replacement sticks to potentially upgrade the original pack. Are 8AH batteries the largest capacity available now? Looks like the ones advertised as 10AH are not up to snuff. Is there a source to purchase just the bare 8AH batteries? I haven't found such a source yet for either overseas or US distributor.

 

10Ah are junk.

8Ah are a bit gimmicky - higher capacity at a lower discharge with lower internal resistance - very similar to the 6.5Ah stock sticks, but with a different voltage response - not generally wise to mix them.

Grid charging and bulb discharging (2X 120V bulbs in series) is a great way to recondition a pack with minimal touch time, but it can take the better part of a week to do it.

You can measure the tap voltages at the orange plug and get your first clue as to the condition of the sticks. If the 10 taps are within 0.2V of each other, they MIGHT be good. If there are outliers, there is almost certainly a bad stick on it...



Without purchasing a new pack, whatever you decide to do is going to be ongoing. You will be revisiting your pack every 3-6 months at best for some form of maintenance - maybe just grid charging if you're lucky.

You may get lucky on the new pack, but it may be a piece of junk.

It's expensive relative to DIY, but the Hybrid Automotive Prolong reconditioning system is worth the cost in convenience.