N-Series Truck Battery Codes: N50 to N200

N-series codes such as N70, N120, N150 and N200 are still printed on battery labels, written into fleet tenders and listed in manufacturers' export ranges, even though the current Japanese standard uses codes such as 115F51 or 190H52. A buyer asking for "N200" and a catalogue listing "190H52" are often describing the same case. This guide explains what the N-series designations mean, how they relate to current JIS case groups, and what to check when sourcing them for trucks and buses. The current JIS system is covered in detail in JIS battery size codes explained.

Where N-series codes come from

Manufacturers' technical data present N-series codes as the old JIS designations. GS Yuasa's technical data for automotive and commercial vehicle batteries, for example, lists each current JIS type alongside an "Old JIS" code. The current standard, JIS D 5301:2019, uses the performance rank, case group, length and terminal position format instead.

What the letters and numbers mean

Two cautions apply to the number:

• For plain N types it tracks capacity. In GS Yuasa's data the listed 20-hour capacity of N50, N70, N100, N120, N150 and N200 equals the number, and Yuasa Battery Thailand lists N100, N150 and N200 at 100, 150 and 200 Ah at the 20-hour rate.
• For NS and Z types it does not. GS Yuasa lists NS40 at 32 Ah, NS60 at 45 Ah, NS70 at 65 Ah, N50Z at 60 Ah and N70Z at 75 Ah.

The capacity shown in GS Yuasa's table is marked as a reference value. Always confirm rated capacity, cold cranking current and reserve capacity on the data sheet of the specific battery.

N-series to JIS: published correspondence

The table below reproduces one manufacturer's published pairing of old and current JIS codes, with its stated capacities and dimensions. The 5-hour rate capacity is shown because the table lists it alongside the 20-hour rate; in JIS D 5301:2019 the 5-hour rate survives only as a reference method.

Source: GS Yuasa, Technical Data for YUASA Automotive Batteries.

Read the case columns before the performance columns:

• N50 to N70 use D cases (about 171–173 mm wide), the same family as many pickup and light truck batteries.
• N100 uses an E41 case, about 41 cm long.
• N120 uses an F51 case, N150 a G51 case and N200 an H52 case. These three share a length of roughly 50–52 cm but step up in width from about 180 mm to 220 mm and 276 mm.

Correspondence is not universal

The pairing of old and new codes is not identical across manufacturers. The case correspondence is consistent in the sources checked (N70 in a D31 case, N150 in a G51 case, N200 in an H52 case), but the performance rank paired with a given N code varies. Bangladeshi manufacturer Rahimafrooz, for example, pairs N70 with 85D31 and NS60 with 55B24, where GS Yuasa pairs them with 65D31 and 46B24. Some manufacturers also sell higher-rated batteries in the same case under codes such as 95D31 or 245H52, which GS Yuasa pairs with other old designations rather than N70 or N200.

For substitution, therefore, "N200 = 190H52" is a statement about the case and a nominal capacity class, not a guarantee of equal cranking performance.

Typical use in trucks and buses

Large N-series batteries are positioned by manufacturers as commercial vehicle batteries. Yuasa Battery Thailand, for example, describes its N100, N120Z, N150 and N200 as heavy-duty batteries for commercial vehicles and trucks. JIS D 5301 also separates batteries into two service classes: Class A for passenger cars and light commercial vehicles, and Class B for trucks, buses, taxis, industrial and construction vehicles, where the heavy-load endurance test uses deeper discharges per cycle.

As a working guide for distributors:

The vehicle's existing battery and the manufacturer's application data decide the correct size; this table indicates where each case family is usually found, not what a particular model uses.

24 V systems: batteries in series

Many medium and heavy trucks and buses use a 24 V electrical system built from two 12 V batteries connected in series: the positive terminal of one battery to the negative terminal of the other. The pair delivers 24 V with the ampere-hour capacity of one battery. ZVEI's battery guidance describes the same principle for 24 V vehicle systems.

When supplying batteries for series use:

• Supply matched pairs: same code, technology, rating and, ideally, the same production batch.
• Replace both batteries together. Pairing batteries of different age or condition leads to unequal charging and shortens the life of both.
• Check the terminal position of each battery. On F, G and H cases the terminals sit at one end, and both standard and reversed (L) versions exist. Confirm each position from the existing installation before ordering.
• Check the carrier. The width step from G51 to H52 is more than 50 mm, so an N200 does not fit a carrier built for N150.

Wiring configurations, climate effects and dry-charged supply are covered in the truck battery selection guide.

Common questions

Is an N150 the same as a 145G51?

In GS Yuasa's data they are the same case and nominal capacity class. Other manufacturers may pair N150 with a differently rated G51 battery, so compare the data sheets.

Can an N200 replace an N150 for more capacity?

Only if the carrier, hold-down and cables accept the wider H52 case and both batteries in the pair are changed. It is not a drop-in change.

Do N-series codes indicate technology?

No. N-series batteries are made as conventional, low-maintenance, maintenance-free and, in some cases, dry-charged batteries. Specify technology and supply condition separately.

Sourcing N-series batteries

Browse truck and bus batteries or JIS batteries. On a fleet or distributor list, give the N code and the current JIS code if known, terminal layout, technology, minimum 20-hour capacity and cold cranking current with test standard, quantity in pairs, and filled or dry-charged supply. Send it through the battery requirement form or upload your parts list.