Flat plate Battery verses Tubular

[electricvehicles]

Hi just wondered what your opinions are on conventional Wet Lead Acid Flat Plate batteries opposed to Wet Tubular Lead Acid batteries.

Personally speaking I was always a fan of the Chloride 3ET175 and the Oldham 3KQ11 monoblocs. But over the past decade I have become a bit of a fan of the overbuilt American Monoblocs. I know according to the specs that pound for pound in weight the Tubular deliver more than the flat plate but I have found if you want a battery for longevity the Flat plate wins hands down.

We supplied a number of buggies to Heathrow 9 years ago, all fitted with Trojan 8V monoblocs. As odd as it seems we are just starting a replacement programme ! 9 years of hard use and they are still delivering approximatey 65% of their rated capacity.

Would really like to hear about your experiences with both the above battery types.

Regards
Dave

[EVguru]

I wouldn't use tubular plate in an on-road EV.

For an industrial application with an 8 hour shift pattern, the tubular plate battery has a much longer potential life. Since the active material is contained in porous tubes, there is very little likelyhood of it being shed and capacity being lost. However the internal resistance is much higher and the Peukert coefficient also and they do rather poorly in on-road applications where the discharge may be in the 1 hour or 1/2 hour range. In fact many tubular cells/batteries will have a very short life if regularly subjected to high current draws, i.e. in excess of 5C. This is certainly the case in the Enfield where flat plate batteries are cheaper, give more range and better acceleration, and in many cases longer life.

Where the current draw can be kept down, like in the case of the Lucas Bedford CFs and Leylan Sherpas, the tubular plate batteries can give a useful life of 20 years or so. Both of these vehicles run a nominal voltage on 216 volts, which is a lot of 6 volt blocks and it's just as well they last well.

[ChrisB]

Must admit the Tubulars in the CF did seem to work very well, but then a lot of R&D went into the Lucas Chloride venture and the batteries where very carefully matched to the discharge curve from memory.

Certainly the set I had which where about 20yrs old still could return 25miles even after being left in a feild for 5yrs

How ever they did suffer badly from fractured tubes etc and seemed to be much more fragile when sulphation takes place

ChrisB

[aminorjourney]

So I see we're back to the good old question of high voltage and low current - or high current and low voltage.

Why is it that Americans tend to do the former and us Brits have cars which do the latter?

[ChrisB]

Dunno if its much to do with the high voltage low current , low voltage high current debate as such, more matching the battery discharge curve to the discharge your going to give it in said application

Milk floats ( the bain of the UK EV market ) where normally only 36/48volts but they had a massive Ah capacity batts and hence the cells would last for years and years

The CF's had far smaller batteries but more of them to keep the currently output from them as close as possible to their C-Rating again they lasted for YEARS

Discharge a battery outside its design characteristics and you'll have problems.......end of


Apple have had a lot of issues with their ipod things and batteries, due to discharge curves being outside the design of the battery limitations and hence the batteries were failing early

ChrisB

[EVguru]

The Americans didn't have Milkfloats to scavenge innapropriate components from.

The aircraft starter-generators readily available as surplus in the US often gave very good (if short lived) performance, although the efficiency wasn't much over 70%. When more suitable motors were sourced, higher voltages were necessary to maintain the previous levels of acceleration and speed. They also of course had cheap flat plate traction batteries from the Golf Car market. At the time here, monoblock traction batteries were a daring innovation.

[Peter Eggleston]

Steady! I don't like that word bain, or should it not be bane?
Peter.

[ChrisB]

Steady! I don't like that word bain, or should it not be bane?
Peter.

Dont look at me Peter the English language was never my strong point far better off with a soldering iron and a pile of wires

ChrisB