{"id":12807,"date":"2026-04-11T07:50:15","date_gmt":"2026-04-10T20:50:15","guid":{"rendered":"https:\/\/thedocaus.com\/blog\/?p=12807"},"modified":"2026-04-21T10:21:12","modified_gmt":"2026-04-20T23:21:12","slug":"cheap-battery-monitors","status":"publish","type":"post","link":"http:\/\/thedocaus.com\/blog\/?p=12807","title":{"rendered":"Cheap Battery Monitors"},"content":{"rendered":"\n

Introduction<\/strong>
A summary of cheap battery monitors owners can use on their cars or battery boxes.<\/p>\n\n\n\n

The original comparison is here <\/a>(BM2 BLE, Kickass (who now re-badge an AncelBM200) and CTEK).<\/p>\n\n\n\n

BM2 BLE (2 models)<\/strong>
The BM2 BLE Battery Monitor works with AGM, Flooded, Gel and Lead-Acid batteries.<\/p>\n\n\n\n

A second model works with Lithium batteries (LiFePO4), but it looks the same as the base unit. Only the package labelling tells you which is which. Once out of the packaging both units look identical.<\/p>\n\n\n\n

The BLE is widely sold under other names.<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

Software<\/em><\/p>\n\n\n\n

The BM2 BLE comes with free software which can monitor 1 battery at once. You can buy third party software which will monitor up to 4 BM2 BLE monitors at once using the Multi-Batt Mon app<\/a> (iOS only).<\/p>\n\n\n\n

Other features<\/em><\/p>\n\n\n\n

When installed on a car battery, the BLE can also perform a cranking test, an alternator charging test and keep a summary of trips taken.<\/p>\n\n\n\n

Data storage<\/em><\/p>\n\n\n\n

The device stores 30 days of data.<\/p>\n\n\n\n

ANCEL BM200 (2 models)<\/strong>
The Ancel BM200 for Lithium Lead-Acid Batteries, including Flooded, AGM, GEL, EFB and LiFePO4.<\/p>\n\n\n\n

One BM200 model works with the Ancel BM200 app.<\/p>\n\n\n\n

The other model has an almost identical sensor paired with a head unit. However, the sensor has 5 “State of Health” LEDs across the sensor. Ranking the battery’s State of Health from REPLACE to GOOD, mirroring what you see on the head unit screen.<\/p>\n\n\n\n

The app BM200 model does NOT work with the monitor with the paired head unit.<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n
\"\"<\/figure>\n\n\n\n

Software<\/em><\/p>\n\n\n\n

The free app model can monitor up to 4 batteries at once.<\/p>\n\n\n\n

The second BM200 model only works with the supplied head unit.<\/p>\n\n\n\n

Other features<\/em><\/p>\n\n\n\n

When installed on a car battery, the Ancel BM200 can also perform a cranking test, an alternator charging test and keep a summary of trips taken.<\/p>\n\n\n\n

Data storage<\/em><\/p>\n\n\n\n

The device stores 30 days of data.<\/p>\n\n\n\n

ANCEL BM300 and BM300 PRO<\/em><\/strong>
There are two models, the Ancel BM300 works with flooded, AGM, Gel and EFB battery types, but NOT lithium.<\/p>\n\n\n\n

The Ancel BM300 Pro<\/strong> works with flooded, AGM, Gel, EFB battery types and Lithium batteries. The BM300 Pro supports 6V \/ 12V \/ 24V systems.<\/p>\n\n\n\n

The BM300 unit is psychically larger than both the Ancel BM200 and BM2 BLE battery monitors.<\/p>\n\n\n\n

Ancel claims the BM300 Pro delivers over 99.6% accuracy. The Doc has one under going testing now on a battery box.<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

Software<\/em><\/p>\n\n\n\n

The free software can monitor up to 4 batteries at once.<\/p>\n\n\n\n

Other features<\/em><\/p>\n\n\n\n

When installed on a car battery, the Ancel BM300 Pro graphs voltage, state of charge and battery temperature over time. It also has a find your car function and a cranking test.<\/p>\n\n\n\n

Data storage<\/em> <\/p>\n\n\n\n

The device stores 72 days of data. The longest time of the models listed here.<\/p>\n\n\n\n

SUMMARY<\/strong>
Any of these units do a decent job, acknowledging they are not precise but give a reasonable approximation of the state of charge and overall health of the battery.<\/p>\n\n\n\n

The most useful feature, in The Doc’s opinion, is the app’s graphing function which reveals a great deal about the battery and the devices drawing power from it.<\/p>\n","protected":false},"excerpt":{"rendered":"

IntroductionA summary of cheap battery monitors owners can use on their cars or battery boxes. The original comparison is here (BM2 BLE, Kickass (who now re-badge an AncelBM200) and CTEK). BM2 BLE (2 models)The BM2 BLE Battery Monitor works with AGM, Flooded, Gel and Lead-Acid batteries. A second model works with Lithium batteries (LiFePO4), but … Continue reading Cheap Battery Monitors<\/span> →<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2},"jetpack_post_was_ever_published":false},"categories":[152,149,159,155,154,156,158],"tags":[],"class_list":["post-12807","post","type-post","status-publish","format-standard","hentry","category-12-volt","category-4x4","category-battery-management-system","category-battery-mangement-sytem","category-battery-monitor","category-bluetooth","category-guide"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p42vG0-3kz","_links":{"self":[{"href":"http:\/\/thedocaus.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/12807","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/thedocaus.com\/blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/thedocaus.com\/blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/thedocaus.com\/blog\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"http:\/\/thedocaus.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=12807"}],"version-history":[{"count":19,"href":"http:\/\/thedocaus.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/12807\/revisions"}],"predecessor-version":[{"id":12838,"href":"http:\/\/thedocaus.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/12807\/revisions\/12838"}],"wp:attachment":[{"href":"http:\/\/thedocaus.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=12807"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/thedocaus.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=12807"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/thedocaus.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=12807"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}