Three AA cells will fit comfortably in the space of a single D cell. Connected in parallel, three 3000 mA-hr 1.2v Ni-MH cells are electrically equivalent to one 9000 mA-hr 1.2v D cell, but three brand new tabless AA cells can be purchased (in 150+ quantity) for less than $2 on eBay.
360 of those AA batteries cost about $250, and they have the storage capacity of a full Honda Insight battery pack, and fit comfortably in the same space.
It seems that it should be possible to solder up 360 of those batteries and use them to replace the 120 D cells in a Honda Insight battery pack, for a fraction of the cost. Even if adding solder tabs to each battery doubled the cost, it would still be only about $500 for the AA cells.
From these pictures...
http://www.youtube.com/watch?v=RN8TLsfTBPo
and http://99mpg.com/blog/batterypacksexpose/
...it looks like a pretty big job. But not impossible.
Has anyone attempted it?
Alternately, brand new tabless 10,000 mA-hr Ni-MH D cells can be purchased in quantity for about $3.25 each on eBay.
Even if solder tabs added $1 each to that price, 120 of them would still only cost $510.
Has anyone attempted to use such batteries to replace the batteries in a Honda Insight battery pack?
Is there anything special about the Ni-MH batteries in one of those battery packs which would prevent this from working?
Hmmm... 10 kW / 144v = 69 A. Ouch, I feel dumb. I should have done that arithmetic.
That's way heavier current than any of the batteries here:
http://www.candlepowerforums.com/vb/showthread.php?79302-NiMh-Battery-Shoot-Out
You'd need a 10C or better current rating. The RC (radio-controlled hobbiest) crowd uses batteries like that, but mostly lithium cells, and the Ni-MH batteries which they sometimes use are mostly sub-C size (rather than D or AA), and they're expensive.
Thank you for educating me!
Well, on to plan B, then. Two Chinese vendors on Alibaba list replacement Honda/Insight 7.2V battery sticks at $47-$65, with a minimum order of just 20 sticks. That would be about $940-1300 for a complete set of fresh batteries:
1. KingKong (cheaper, rated 10C & 10A-hr, 1 year warranty)
2. Yabo (cost more, rated 15C & 8A-hr, 5 year warranty)
Has anyone here ever bought from a Chinese vendor on Alibaba? Used their escrow service? Got any advice for doing that?
Also, some of the listings show particular model years; e.g., "2006" or "2003-2005." Is there really any difference (as long as they're in the 1999-2006 range)?
Also, the "KingKong" listing, above, says, "Single 10000mah D cells are also available, you can assemble the stick with our D cells by yourself." My guess is that'd be a lot of extra trouble for little or no savings. Does anyone disagree?
Those must be different cells. For these batteries, KingKong claims to support a 50A charge rate and 100A discharge rate.
This is copied/pasted from KingKong's Alibaba listing (for the link go to www[dot]burtonsys[dot]com/ecomodder13610.html#2):
FOB Price: US $45 - 47 / Piece
Specifications
7.2V replacement NiMH cells for Honda Civic Hybrid
Capacity:10000mah
50A charge rate&100A continous discharge
warranty:3 year
NiMH Rechargeable Battery pack for Honda Civic and Insight hybrid cars
Apply scope: Honda Cvic and Insight 2003-2005
Voltage: 7.2V.
Capactiy :10000mah( Original 6500mah)
Size: 35mm*384mm
Continue Discharge Rate: 100A
Support 50A charge rate
Warranty: 1year
Life span: above 4 years
6 Cell per stack with both ends stainless square and hexagonal standard electric car battery nuts
Our NIMH replacement sticks have passed Vehicle test, we increased the capacity from 6500mah to 10000mah to improve the performance.
Single 10000mah D cells are also available, you can assemble the stick with our D cells by yourself.
I do see that they weren't very careful with their listing. Note that it claims a 3 year warranty near the top, but a 1 year warranty further down. (My guess is that warranty claims w/ Chinese vendors might be challenging, anyhow.)
The Yabo listing is similar, but with higher price, lower capacity and higher discharge rate. They give specifications both for individual cells and 6-cell sticks:
FOB Price: US $55 - 65 / Piece
Specifications
1.Honda Hybrid car battery for sale
2.For Honda Civic/Insight/Prius
3.7.2v/6500mAh
4.HEV level D size cells
NiMH Hybrid Car Battery Pack 7.2V for Honda Civic/Insight
Voltage: 7.2V
Capactiy: 6500mAh/8000mAh
Continue Discharge Rate: 150 ampere
6 Cell per stack with both ends stainless square and hexagonal standard electric car battery
Nuts and inter-connecting cups, rubber heat sealing sleeves and all necessary accessories.
Just plug and replace works that everyone can do it.
For product images, detail technical spec or any other question, feel free to contact.
Item / Specification
Dimensions / Outer Diameter (mm) / 32.2±0.07
/ Over Height (mm) / 60.5±0.2
Approximate Weight(g) / 165
Nominal Capacity(mAh) / ≥6500(IEC)
Nominal Voltage(V) / 1.2
Internal Resistance (mΩ) / ≤1.6
1.2V Discharge Capacity1.2V Cut / ≥70%
Specific Energy (Wh/kg) / ≥45
Peak Power (W) / ≥130(DOD50%)
Specific Power(W/kg) / ≥850(DOD50%)
(30C Discharge,70%SOC,0.8V Cut-off) / ≥10S
Peak Charging (15C Charge, 50%SOC, 1.66V Cut-off) / ≥10S
Max Discharge (15C Discharge, 70%SOC,0.8V Cut-off) / ≥60S
High Temperature Performance(50°C Charge/Discharge Capacity Rate) / ≥70%
Low Temperature Performance(-20°C Discharge Capacity Rate) / ≥80%
Charge Retention(30 Day) / ≥75%
Working Temperature / -20°C to +55°C
Storage Temperature / -40 to +65°C
Cycle Life(C/3 Charge,1C Discharge) / ≥800cycles
2,D Type NI-MH Battery Package(7.2V HEV Battery Bar)
Item / Specification
Dimensions / Outer Diameter (mm) / 34.0
/ Over Length (mm) / 396
Approximate Weight(g) / 1100
Nominal Capacity(mAh) / 6500(IEC)
Nominal Voltage(V) / 7.2
Internal Resistance (mΩ) / ≤9.6
7.2VDischarge Capacity7.2V Cut / ≥70%
Specific Energy (Wh/kg) / ≥45
Peak Power (W) / ≥130(DOD50%)
Specific Power(W/kg) / ≥850(DOD50%)
Peak Discharge(30C Discharge, 70%SOC, 4.8V Cut-off) / ≥10S
Peak Charge(15C Charge, 50%SOC, 9.96V Cut-off) / ≥10S
Max Continuous Discharge(15C Discharge, 70%SOC, 4.8V Cut-off) / ≥60S
High Temperature Performance(50°C Charge/Discharge Capacity Rate) / ≥70%
Low Temperature Performance(-20°C Discharge Rate) / ≥80%
Charge Retention(30 Days) / ≥75%
Working Temperature / -20°C to +55°C
Storage Temperature / -40 to +65°C
Cycle Life(C/3 Charge,1C Discharge) / ≥800cycles