Berlingo cooling and battery failure

[Grumpy-b]

Looking at a info on a number of failed Berlingos, including my own, a definite trend seems to exist.
The highest number of failure of batteries seems to be in the Centre Pack. Especially leakage generally caused by split cells.
All the other Battery packs have only one side face of any battery in contact with another, the centre cell of the centre battery are totally enclosed.

I think the failures could be associated with lack of cooling to this pack.
The other packs can also loose some heat to their surroundings. These cant.

I dont have any way of temperature checking these and doing comparisons. So I am going to split my battery cooling circuit and add an additional pump. This will have a separate feed to the centre pack(I have already had to cut these pipes to replace the ends that a previous owner had filled with Silicone, so I dont have huge modes to make to the existing pipework. A T at the Rad end, mounting and wiring for the pump and a connecting pipe to the Battery pack pipe end I have already had to separate to replace.. I will still use the common return pipe.

Any thoughts!

Grumpy-b

[ChrisB]

Interesting thoughts, I must admit my battery failures appeared to be all due to the seperator failure problem that was reported here
http://www.danskelbilkomite.dk/report.pdf

Rather than a cooling issue.

I have got several batteries here which are showing the exact same problems as the report and also one battery with has blown up again due to a seperator shorting out and the cell deciding to dump 1.2volts @ 100Ah between its plates in about 0.1 sec this then causes it to vapourise its electrolyte equally fast and actually cause a small ( I thought it was quite large) steam explosion which cracked the whole top and side of that battery open. This is generally the cause of split cells, the previouse owners I think have a battery go bang on them and after a quick bit of research then sell the vehicle double quick cos they know the problem

So I'm not sure that its a cooling issue more down the the fact of these faulty batteries that where produced up to 2000.

I've never really found the batteries get that hot, the only time I've seen my pack get to 30C (measured via EVlite which is from the sensor in the upper pack under the bonnet) is during a maint charge and climbing a hill into brighton on the L&B run. I've checked the out going side of all the packs and have never found they are much more than slightly hand warm, of course this might not mean that the cells are as cool of course, especially as you say that center pack ones.

ChrisB

[Teslas fag packet]

Could it be possible that the middle cell in the middle pack doesn't get watered equally, my van had a new middle pack in 2005 the middle pack only lasted two years from new. What were they doing to her

[Grumpy-b]

I realise the failure is not in itself over heating, but if the batteries do get hotter they will loose more electrolyte through evaporation. I f you see 30 degrees on the well cooled outside cell, as is the sensor one, then the middle pack middle row will im sure be much much hotter.
My thinking is to try and reduce the reasons /causes that lead to failures. Lack of water is almost certainly the main cause leading to failure as chris described. But why does the centre pack seem to have more failures. Heat.

Grumpy-b

[ChrisB]

I'm not convinced its a lack of electrolyte problem TBH, from what I've found if these batterys run out of electrolyte they just go high resistance.

As for it always happening to the center pack, this wasnt the case for mine, I had a failure in the front pack first (that one went bang) then the top front was pretty poor and the middle pack went equally sick.

It wasnt only the center pack

Personally I think a lot of the failures are purely down to abuse by the orginal drivers folk expect to drive these vehicles in the same way as normal ICE powered vans. Now while it is true you can drive them and in many cases they actually go better than the ICE powered vans (especially the deisel version) driving the electrique about in, lets call it looney mode, does put a lot of stress on the batteries without a doubt and also well exceeds their specs for discharge rates and so I think it will cause them to go pop.
Also if its anything like the days when I use to drive the bedford CF electric, if as a employee you where given an electric van to drive the employee use to think he was being punished and then take his anger out on said EV in a vain attempt to blow it up and so he could get what HE felt was a proper van back

I saw this attitude time and time again in the 80's with the CF electrics

ChrisB

[Grumpy-b]

I realise the failure is not in itself over heating, but if the batteries do get hotter they will loose more electrolyte through evaporation. I f you see 30 degrees on the well cooled outside cell, as is the sensor one, then the middle pack middle row will im sure be much much hotter.
My thinking is to try and reduce the reasons /causes that lead to failures. Lack of water is almost certainly the main cause leading to failure as chris described. But why does the centre pack seem to have more failures. Heat.

Grumpy-b

[ChrisB]

I think the only real way to tell this is for someone to drop a center pack out and install a temp sensor in the center of that pack

I will say that I've always wondered how well the packs do get cooled as the cooling circuit is a bit hit and miss with so many cooling pipes and circuits in parallel with each other.

ChrisB