Days after buying his Samsung Electronics Co. Galaxy Nexus smartphone from Verizon Wireless, David Jacobs found himself switching off the fourth-generation broadband connection that had drawn him to the $300 device in the first place.

'I love everything about the phone, but with 4G on, it just sucks down the battery,' said the 25-year-old Mr. Jacobs, who lives in Los Angeles and works in digital advertising. 'It's very frustrating. Why can't I get a phone to last a whole day?'

Mr. Jacobs is among the rising number of 4G smartphone users who are discovering their speedy broadband service also zips through battery life. The main culprit is spotty 4G service -- even in the nation's largest cities -- which requires the phones to search constantly for a signal, draining their batteries.

Fourth-generation service is just starting to take hold, but complaints about battery life could slow the push by wireless carriers to convert customers to the higher-speed networks. Smartphone makers, however, are working on ways to respond to the new power demands.

Verizon Wireless, AT&T Inc. and Sprint Nextel Corp. are investing billions of dollars to expand their 4G networks over the next two to three years on a technological standard known as long-term evolution, or LTE, with the promise of speeds of as much as 10 times those of the ubiquitous 3G service.

The carriers want customers to switch to the new networks because the technology requires less bandwidth to deliver data, leaving room for more customers to download music or television shows. And with faster download speeds, 4G users are inclined to use more data, meaning they will need pricier service plans.

'Every time we add a customer to LTE, it is a much more efficient and cost-effective network than the 3G network,' Verizon Communications Inc. Chief Financial Officer Fran Shammo told investors at a conference last month. Verizon Communications and Vodafone Group PLC co-own Verizon Wireless.

Device makers such as Samsung and Motorola Mobility Holdings Inc. are banking on their 4G devices to put a dent in sales of Apple Inc.'s iPhone, which continues to gain market share even though it lacks the faster service. Apple, with its new iPhone 4S, was the only smartphone manufacturer in the top five to gain U.S. market share in last year's final quarter, according to comScore.

The spottiness of 4G stems at least in part from the measured approach carriers have taken to it, rolling out the service city by city. There were just 6.3 million subscribers of 4G LTE in the U.S. at the end of last year out of a total of 138.4 million smartphone users, according to research firm Informa Telecoms & Media.

Verizon Wireless's 4G network covers 200 million Americans, while AT&T reaches less than 80 million. Sprint, which has just begun to build out its 4G LTE service, offers 4G today on a competing technology known as WiMax that it will phase out. Despite the fact the carriers are offering 4G service, they don't have it on every block, as they do with 3G,' said Carl Howe, a vice president for research firm Yankee Group. 'So you've got a situation where the phones are sending out their signals searching and searching for a 4G tower, and that eats up your battery.'

Verizon Wireless and Sprint both said through representatives that battery life should improve as network upgrades reduce the need for phones to search for a signal. An AT&T spokesman declined to comment.

But erratic service isn't the only problem. Battery technology isn't keeping pace with smartphone advances. As consumers demand more powerful smartphones packed with features, device makers are rapidly improving processing speeds and the operating software that drives the phones. At the same time, developers are increasing battery life by just 1% each year, on average, according to Mr. Howe.

Samsung recently promised to roll out smartphones this year that can last all day with regular use on a single charge by bulking up the batteries themselves and reworking how phones seek out wireless signals. Last month Motorola Mobility brought out a version of its Droid Razr smartphone, known as the Maxx, with a larger battery for longer life.

'Of course Motorola came out with a better battery life right after I bought my regular Droid Razr' a few days after Christmas, said Dan Antonucci, a 31-year-old Los Angeles resident.

Mr. Antonucci said he turns off Verizon Wireless's 4G LTE connection while in his office at a casting agency, though he uses the high-speed mobile network to watch basketball games at home. 'I can sit on one side of my couch and get a signal, but on the other side I don't, and the phone just searches,' he said.

Bita Goldman, 28, an attorney in New York, said she carries an extra charger with her for her HTC Evo smartphone, which runs on Sprint's WiMax 4G network. 'By 4 o'clock, I have to charge it,' said Ms. Goldman, who typically keeps her phone's 4G connection switched off. She said she has considered buying the $55 extended-life battery, but found it too bulky.

Tom Harlin, an HTC Corp. spokesman, said HTC is building longer-lasting batteries and updating the phones' software.

Most customers, though, are still on 3G networks that don't demand as much from their batteries. Jason Taylor, a manager of the Wireless Zone store in Kansas City, Mo., which sells Verizon Wireless products, said 4G devices are selling well but they are geared more for customers who are interested in streaming video and using lots of data.

'For people looking to just send email and do some Web surfing, we sell them the iPhone,' Mr. Taylor said.

Greg Bensinger

• connection [kə´nekʃən] n.联系；关系；联运 (初中英语单词)
• device [di´vais] n.装置；器具；策略 (初中英语单词)
• advertising [´ædvətaiziŋ] n.广告a.广告的 (初中英语单词)
• constantly [´kɔnstəntli] ad.经常地；不断地 (初中英语单词)
• convert [kən´və:t, ´kɔnvə:t] v.转变 n.改变信仰者 (初中英语单词)
• working [´wə:kiŋ] a.工人的；劳动的 (初中英语单词)
• respond [ri´spɔnd] v.回答；响应；有反应 (初中英语单词)
• customer [´kʌstəmə] n.顾客，买主，主顾 (初中英语单词)
• financial [fi´nænʃəl] a.金融的，财政的 (初中英语单词)
• conference [´kɔnfərəns] n.讨论(会)；会谈 (初中英语单词)
• manufacturer [,mænju´fæktʃərə] n.制造人；工厂主 (初中英语单词)
• research [ri´sə:tʃ] n.&vi.调查；探究；研究 (初中英语单词)
• despite [di´spait] prep.尽管 (初中英语单词)
• yankee [´jæŋki] n.美国佬；美国公民 (初中英语单词)
• charge [tʃɑ:dʒ] v.收费；冲锋 n.费用 (初中英语单词)
• agency [´eidʒənsi] n.代理商；机构；代理 (初中英语单词)
• attorney [ə´tə:ni] n.代理人；律师 (初中英语单词)
• manager [´mænidʒə] n.经理；管理人；干事 (初中英语单词)
• battery [´bætəri] n.炮兵连；炮台；电池 (高中英语单词)
• expand [ik´spænd] vt.张开；膨胀；扩大 (高中英语单词)
• switch [switʃ] n.开关 v.转换 (高中英语单词)
• efficient [i´fiʃənt] a.有效的，有能力的 (高中英语单词)
• offering [´ɔfəriŋ] n.提供；礼物；捐献 (高中英语单词)
• kansas [´kænzəs] n.堪萨斯(州) (高中英语单词)
• speedy [´spi:di] a.快的，迅速的 (英语四级单词)
• evolution [,i:və´lu:ʃən] n.进化；发展；发育 (英语四级单词)
• network [´netwə:k] n.网状物 vt.联播 (英语四级单词)
• banking [´bæŋkiŋ] n.银行业 (英语四级单词)
• version [´və:ʃən, ´və:rʒən] n.翻译；说明；译本 (英语四级单词)
• culprit [´kʌlprit] n.犯人；罪犯 (英语六级单词)
• spokesman [´spəuksmən] n.发言人 (英语六级单词)
• charger [´tʃɑ:dʒə] n.军马；委托者；控诉者 (英语六级单词)