Honda Insight Forum banner

21 - 33 of 33 Posts

·
Registered
Joined
·
275 Posts
Discussion Starter #21
I put the last 3 sticks on charge this morning about 7AM and later left for work...

The long suffering wife rang me about 10.30am to say there was a fairly loud bang followed by another and it appear 2 of the remaining 3 cells have outgassed rather aggressively. one was fizzing and the other had blow one of the terminal caps off, released an amount of black powder over the work bench, washing (that was in there drying) and up the wall.

So Peter... I may need another stick or two! I have not tried charging the leaky pair I removed but I am now a little hesitant to try them.
 

·
Administrator
Joined
·
10,615 Posts
Oh dear..

Don't those chargers shut off when cells are full?

Is this your old green sticks?
 

·
Registered
Joined
·
275 Posts
Discussion Starter #23
Old green sticks yes

the charger are set to charge at 6A max and turn off EITHER when they reach a 5mV delta peak (which most do around 4.5-5Ah of charge) or after 7Ah of coulomb counting.

I will be home about 7pm so will have a proper look as to what has happened then. Thankfully the Wife was in and turned off the chargers, but I have no idea what state of charge they were at when they went. They went on charge around 7am, most cells were taking 1.5 hours to discharge then a short rest so charging should have commenced around 8,30-9AM, so they had been charging for 1.5 hours maybe, so should have been close to capacity.
 

·
Registered
Joined
·
275 Posts
Discussion Starter #24
So a little update.

I came home to find 2 of the 3 stick I had on charge looking much the same:



I found the positive terminal hanging on the end of the cable, this shows where it has distorted before popping off:



And this is the inside of the end cell:



The chargers were all set the same (they have not been powered down at all while charging) Charge a 6s NiMh pack at 6A max to a 5mV Delta peak with a 7,000mAh cut off if the delta peak is not reached. So I can only assume these cells may have been leaky but not obviously so and the stress of continuous charging has caused them to overheat and build pressure to the point of popping. Any other thought I would be glad to hear, but I'm not charging them to excess and just below 1C rate of charge so as far as I can see I'm doing nothing to stress them to excess.

Peter: many thanks for your email, yes I need to replace these two, (I doubt I can scrape enough electrolyte off the wall to fill these back up) and I think a spare might be a sensible addition. Let me know what I owe you for them and I will PayPal across the monies!
 

·
Registered
Joined
·
275 Posts
Discussion Starter #25
So... here we are again P1449 my old friend! I see you have brought P1568 to the party.

I have been grid charging this pack for a while twice a week (that is the frequency of the P1449s) and I went on holiday for a fortnight. On my return the pack voltage was sub 50v so I decided a full 'simple cycle' refresh would be a good idea. It proved to be the straw to break the camels back and I now have the P1568. I checked the stick pair voltages at the BMS and I now have the following:
12.93
11.85
15.75
15.79
15.79
13.01
0.00
15.67
14.40
15.57
15.75


So something is very wrong in the middle and not entirely happy further up the pack either. I've spoken to Peter who is helpful as ever. Once I have some space on my bench I'll pull the pack and see what lies beneath.

I'm guessing 6 sticks to swap.
 

·
Administrator
Joined
·
10,615 Posts
If the readings are accurate then something is very amiss.
It may be the pack has had a near melt down or overheating event.
I would expect to find leaking sticks and dead cells with those voltages..
Disassemble pack, remove all sticks and measure all 20 stick voltages on the bench.
Post results here.
 

·
Registered
Joined
·
275 Posts
Discussion Starter #27
Thanks for your input Peter as always. Yes the plan is strip the pack, measure the cells, I expect I may need to give the pack frame a good wash because that 0v tap I assume has a lot of electrolyte around it! I will post individual stick (maybe even cell) voltages and I now have a charger that measures internal resistance so I may measure those too.

looks like I have some 15Ah lithium Cobalt cells. not my preferred chemistry, but from an implementation point of view if they work when they die I can drop in NMC or NCA cells.
 

·
Administrator
Joined
·
10,615 Posts
You don't have an 0V tap.

You have ten voltages and the pack break which should measure 0V.
 

·
Registered
Joined
·
275 Posts
Discussion Starter #29
Right, Pack pulled and single cells measured (cells marked with * were new on the last rebuild):
1, 4.76V
2, 7.78v
3, 3.84v
4, 7.91v*
5, 7.63v
6, 7.91v*
7, 7.72v
8, 7.89v*
9, 7.90v*
10, 7.70v
11, 7.78v*
12, 5.07v
13, 7.79v
14, 7.59v
15, 7.90v*
16, 6.31v
17, 7.64v
18, 7.58v
19, 7.73v
20, 7.79v

So sticks 1,3,12 and 16 definitely need changing, I suspect 5,14, and 18 may not be in tiptop condition. I intend to take internal resistance measurements (as I see my charger has this as an option) of the cells and see if we have any that are significantly higher that average. I will post the results hopefully in the next day or so.

Peter, can you drag some sticks out of storage for me please, as you can see I'm going to want at least 4 probably a few more, I will try and email you a firm number tomorrow.
 

·
Administrator
Joined
·
10,615 Posts
The pack is a hell of a state..
What has been going on?
Grid charging with no fan?
What colour sticks are they?
I suggest ring me.
 

·
Registered
Joined
·
275 Posts
Discussion Starter #31
The sticks are the teal wrapped ones originally then you sent me some orange ones when I last rebuilt it (start of this thread). The pack has just slowly degraded, lots of recalls. Then I got to the stage where I was getting P1449 errors about every 10 days (weeks commuting, little use over the weekend and then a P1449 on Tuesday morning n the way to work, like clockwork). Then I went to car sharing and only drove every other day, at that point I was grid charging twice a week. I let the car sit for 3 weeks while I went on my hols, came back to a 48v pack. I decided to do a simple cycle to it in preparation to run it again and that got me to this point. The fan has been working but the weather has been warm of late... and its a black car... sat in the sun!

I'll give you a ring.
 

·
Administrator
Joined
·
10,615 Posts
Have you removed them all from the case?
You def need to do that to check for electrolyte leaks.
Accurately check the lengths of all the sticks as well.
Discard any that are more than a mm or so longer than the orange ones or show signs of heat shrink stretch or expansion.

IMO You would be a lot better off with a brand new set of the new better quality sticks.
Otherwise you will be repeating this operation at regular and very frustrating intervals.

You could be a UK LTO Lithium guinea pig.. See my forum post and on FB.
 

·
Registered
Joined
·
275 Posts
Discussion Starter #33
I will measure all up the next couple of evening. To be honest I want to limp this pack on and go lithium in the longer term. I'm just not sure LTO is the direction I want to go. How easy and costly are the LTO modules to get in the UK? Expect a call shortly unless your mobile number has changed :)
 
21 - 33 of 33 Posts
About this Discussion
32 Replies
4 Participants
Puggie
Honda Insight Forum
We’re the ultimate Honda Insight forum to talk about Honda’s hybrid car and its fuel economy and specs!
Full Forum Listing
Top