China installed 87.2 GWh of EV batteries in September — a fresh monthly high for the year, but the slowest annual growth since April. The two facts sit together uneasily, and they tell you most of what's happening in the world's largest battery market.

Figures released Thursday by the China Automotive Battery Innovation Alliance (CABIA) show installations up 14.7% year-on-year and 10.4% from August's 79.0 GWh, according to data compiled by CnEVPost. That growth rate marks the second consecutive monthly slowdown, down from 33.5% in July and 26.3% in August.

The market is still setting records. It's just setting them more slowly.

What is carrying the market?

Lithium iron phosphate (LFP), overwhelmingly. September installations reached 74.5 GWh, up 19.9% year-on-year and 10.3% month-on-month — also a high for the year.

LFP's share of total installations came in at 85.5%, a hair below August's record 85.6%, which ends a three-month run of record share. For perspective: five years ago, ternary and LFP installations were roughly neck-and-neck. LFP now outsells ternary by better than six to one.

Ternary installations totaled 12.3 GWh — down 10.9% year-on-year, though up 11.7% month-on-month, breaking three straight months of sequential declines. Ternary's share edged up to 14.1% from 14.0% in August, still well below year-earlier levels.

In plain words: the chemistry war is over, and LFP won.

What did the first three quarters deliver?

Domestic installations for the first nine months totaled 576.3 GWh, up 16.7% year-on-year — a touch slower than the 17.0% recorded through August. LFP accounted for 477.2 GWh (82.8% of the total, up 18.5%); ternary managed 97.9 GWh, up 7.3%.

CABIA credited the expansion of commercial new energy vehicles and higher battery capacity per vehicle, with battery-electric trucks and special-purpose vehicles making significant contributions.

What's happening beyond installations?

Production keeps running well ahead of what China's vehicles absorb. Combined power and energy storage battery output hit 237.8 GWh in September, up 57.3% year-on-year.

Combined sales of the two categories reached 222.7 GWh, up 52.0% year-on-year. Power battery sales rose 35.0% to 149.2 GWh; energy storage sales doubled-plus, up 104.4% to 73.5 GWh — a full third of total sales.

Exports added 44.0 GWh, up 64.5% year-on-year, equal to 19.7% of sales. Power battery exports reached 28.4 GWh (+60.9%); energy storage exports came to 15.6 GWh (+71.4% year-on-year, though down 11.9% from August). Nine-month exports totaled 302.9 GWh, up 51.6%.

CABIA said power battery exports grew faster than energy storage exports in the first three quarters, driven mainly by rising vehicle exports and automakers' overseas factories gradually starting production.

Production rising 57% while installations grow 15% is not a market in balance.

What to watch next

October's installation figure will show whether the growth slowdown is seasonal noise or a trend. Also worth tracking: whether ternary's month-on-month rebound holds, and whether energy storage exports resume their climb after August's dip.