144V Battery Issues

Ok, how about a breakdown of the numbers... It's rated at 6.5 Ah, I believe this to be it's useable capacity, that's it's capacity within the 20%-80% DOD.

(144V * 6.5Ah * 60Min)/10kW = 5.616 Min (Maximum Run Time) So, the IMA draws 10,000 watts @ 144 Volts at full tilt. That comes out to 69.45 Amps * 5.616 Min = 390AmpMinutes 390AmpMin / 60Min = 6.5Amp Hours.

So, a new pack with a full charge "Should" pull up a mountain pass for 5 to 6 minutes before it is empty. This has been my experience, and others observations would prove it true.

So, 1Min 45Sec (1.75 Min) of assist equates to: 69.45Amps * 1.75 = 121AmpMin/60 = 2.02AmpHours of Capacity.

I'd say 6.5Ah is not the same as 2Ah.

I believe that my capacity is falling off aswell, though I have yet to go out and test that. It used to match the
calculations, as I went out and tested it to insure that the battery actually delivered it's rated 6.5Ah. And it
did at one time run for 5Minutes and some change.

I guess, reduced capacity is not quite the same as aa CEL (Pack Replacement) Event in which cells have become reversed.

Since reduced capacity is just that, kinna like a smaller tank.Where as cell reversal CEL is reduced voltage, kinna like buying 98 Octain, but getting stale winter 82. The later could cause problems with the inverter and DC-DC converter, where as Recals are simply annoying.

Had Honda wanted to they could have made the computers program adapt to the changing capacity, so that it would now know that the total capacity is currently 2.1Ah and adjust the display accordingly. Unfortunently they did not, and so even the most non-technical of drivers see the abrupt drop of a recal event. We may have never known.

Though no doubt some would have still been able to measure the drop in capacity, It may not have been so obvious.

So, Is this something that Honda should "fry" for? Do they state anywhere that the battery pack is Garenteed to have a 6.5Ah capacity for 80,000 Miles? Or, do they state that the battery pack won't experience a much more catastrophic cell reversal or loss for 80K?

Hummmm. I want a new pack, though It's too late for me now. I've just passed the 80,000 mile mark, drat.


Just crunching some numbers.
144v @ 12A = 1.7kW ( invisable charge )
12v @ 80A = 0.9kW ( DC/DC at full draw )
1.7 - 0.9 = 0.8kW ( min charge to batteries at full invisable charge )

144v @ 45A = 6.5kW ( full regen )
144v @ 90A = 13 kW ( full assist ) That's more than 10kW ? humm

humm, I wonder why you observed 90A = 13kW?

Actually I do have some dc/dc information (via a shunt). I measured about 10a with minimal loads. I measured about 30a with normal loads (lights, heat ) It was rare to see 60a, which only happened with everything on full blast, and with a discharged accessory battery and full load I don't believe the load exceeded 65a. I'll have to track down my notes for more detailed numbers, if anyone is interested.

Anyway, L8r

TOKYO: Japan's Sanyo Electric and auto giant Honda Motor on Friday said they will jointly develop batteries for hybrid cars powered by both a gasoline engine and an electric motor. Honda currently buys batteries for two models of hybrid vehicle from a unit of Matsushita Electric Industrial, a company spokeswoman said. "We have decided to work with Sanyo to diversify the firms we procure our parts from," she said, adding Honda would continue its ties with Matsushita. Sanyo, a major electronics maker, has an agreement to supply batteries to Ford Motor, which is preparing to introduce a new hybrid vehicle. "We also wanted to introduce our batteries in the Japanese market through tying up with a major automaker like Honda," said Sanyo spokesman Derek Wentz. No specific timing had been decided for the introduction of Honda hybrid vehicles with Sanyo batteries, the company representatives said. But the Nihon Keizai Shimbun newspaper reported the car would be developed in two to three years. "By incorporating Honda's hybrid system technology, Sanyo aims to develop a battery system that will help slash production costs, as well as reduce gas emissions and enhance fuel efficiency," the financial daily said, without citing sources. "The tie-up is expected to enable the two firms to gain ground on the alliance of Toyota Motor Corp and the Matsushita Electric Industrial Co Ltd group, which now dominates the domestic market," it said.
Source : Economic Times (Online Edition)   (4/12/02)