Battery 2
Note that the Battery from most cars interchange with the Datsun 1200 -- even large batteries. The A12 does not need a high-power battery and often a worn battery that can no longer start a V8 will work fine in your 1200 for another year or two. The 1200 can take quite large batteries, although newer very small batteries will save weight thus gaining "free" horsepower. In Japan, 1200s came with very small batteries.
Overview
Also see Battery Maintenance and Cable Cleaning.
Datsun 1200 stock large battery (big enough for a V8) is good if you want to use the stock hold-down and tray. Otherwise fit a smaller battery. One with half the weight is plenty for the A-series engine.
I've been running the Odyssey PC680MJT batteries in both 1200's. One has been in use for a year, the other has been in 2 years. 220 CCA, very small, and 15# [pounds]. http://www.summitracing.com/parts/ODY-PC680MJT/
Note that GM batteries with side-mounted terminals won't work unless you change the battery cable terminals to match.
Australia
What size battery was standard for Datsun 1200 in Australia?
Japan
In Japan, the 1200s come with a very small battery, (tall, but small).
JDM battery, takes up only a portion of the battery tray. This is powering a street/race A14
Type: 38B19L specifications * Height: 20.4 mm (7-7/8 inch) * Width: 18.8 mm (7-3/8 inch) * Depth: 12.8 mm (4-7/8 inch) * Weight with acid: 9.7 kg (21.4 pounds) * CCA: 274 * Capacity @ 20 Ah: 33-35 * Reserve Capacity Minutes: 52
B110 * Battery: 40B19R * Length: 19.7 cm * Width: 12.9 cm * Height: 20.0 cm * modern spec: TH: 222 Capacity 5hrs (Ah) 28 Ah 
* Tray * Length: 20.5 cm * Width: 13.5 cm
Battery Tray - 20.5 x 13.5 cm
keywords: バッテリ バッテリートレー
Part Numbers
Also see Battery Part Numbers
B120 8910- * 24420-M7000 FRAME-BATTERY FIX $8.29 USD 24420-J0600 F/COLD ZONE $11.15 USD * 24422-18001 ROD-BATTERY FIX LONG * 24422-G1600 ROD-BATTERY FIX F/50A * 24422-H1000 ROD-BATTERY FIX SHORT
Battery 8910- * B441M-3B197 * B441M-3B201 * B441M-5D237
* 24428-89900 TRAY-BATTERY -8910 * 24428-89920 TRAY-BATTERY 8910- $24.61 USD F/COLD ZONE -8910
Body Sheet Metal
The battery platform/box/frame is spot-welded to the right hoodledge (inner fender, see Hoodledge).
Angled: early 1200s 24426-H1001 BRACKET-BATTERY SUPPORT 24427-H1000 STAY-BATTERY BRACKET SEDAN <> 24427-H1001 http://img.photobucket.com/albums/y47/dwaynE2100/Datto/EngineBay-002.jpg http://img.photobucket.com/albums/v316/d-hole//312678_2014973619590_1401316972_31824478_1483769309_n-1.jpg
North-south: late 1200s 64135 24426-G1600 BRACKET-BATTERY SUPPORT 8504-8901 24421-G1900 2 0 22421-G1900 BRACKET-BATTERY SUPPORT 8901- http://img.photobucket.com/albums/zz255/j05h120y/Datsun%201200%20Ute/DSCN0487.jpg 
USA
The best fit is with the Positive terminal on the right side of the battery top.
USA models originally used a large full-size battery (Group 24). With today's better batteries, a much smaller battery is all you need.
* Group 24: 41 pounds. 6.75 wide, 8.75 in Tall, 10.87 long * Group 25: 36 pounds. 6.75 wide, 8.75 in Tall, 9.69 long * Group 26: 31 pounds. 6.75 wide, 7.81 in Tall, 8.75 long
A Group 26 battery is a lot lighter and more powerful than the original specification. But it doesn't fit very well using the original hold-down as you can see in this photo:
* Sears Group 26 Battery * Sears Group 24 Battery * All Sears Batteries for Datsun 1200 Group 24 * CCA: 525 * Reserve Capacity: 90 Group 25 * CCA: 525 * Reserve Capacity: 85 Group 26 * CCA: 525 * Reserve Capacity: 80
Reserve Capacity (RC) is the number of minutes a fully charged battery at 80° F (26.7° C) can be discharged at 25 amps until the voltage falls below 10.5 volts. More RC is better in every case. To convert Reserve Capacity to approximate Ampere-Hours, multiple RC by 0.4.
small battery
Small Advanced Battery
http://www.summitracing.com/parts/ODY-PC680MJT/ Odyssey Battery PC680MJT * $160 * 15 pounds * 220 CCA * Top Post * Reserve Capacity 24 minutes * Length (in) 7.250 in. * Width (in) 3.000 in. * Height (in) 6.650 in.
http://www.braillebattery.com/index.php/batteries/b106/ Six pounds, $140USD B106 
http://i297.photobucket.com/albums/mm219/ddgonzal/sightings/forum/ODY-ER30.jpg Odyssey ER30 * CCA: 450 * Capacity (Ah): 34 * Reserve Capacity: 60 * Weight (Kgs): 9.5 * price: $290 USD * Length: 9.8" * Width: 3.8" * Height: 6.1"
Battery Hold-down
The genuine battery hold-down: * 24420-J0600 For batteries 6.75 wide, 8.75 in Tall, 10.87 long (Group 24 size)
Factory J-Hook 24424-H5000 (9.25" 235mm)
Cable Routing
The Negative battery cable (black cable) bolts to the timing cover bolt. It is important to have the engine grounded like this, and not the body -- because the starter uses the most power, the cable needs to go directly to the engine block.
Factory Photo
ddgonzal's 1972 1200
The positive cable is bolted directly to the starter solenoid:
Voltage & Amps
See Main Article: Voltage regulator
Battery Relocation
See Main Article: Battery Relocation
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