# High end battery monitor? Lead acid 2 to 9 batteries **URL:** \ **Category:** GEM Forum\ **Created:** [July 22, 2017, 3:05am UTC](https://community.electricforum.com/t/high-end-battery-monitor-lead-acid-2-to-9-batteries/12598 "2017-07-22T03:05:29Z")\ **Posts on this page:** 11\ **Page:** 1
**Author:** ![Inwo](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/inwo/32/1067_2.png) [@Inwo](https://community.electricforum.com/u/Inwo)\ **Post date:** [July 22, 2017, 3:05am UTC](https://community.electricforum.com/t/high-end-battery-monitor-lead-acid-2-to-9-batteries/12598/1 "2017-07-22T03:05:30Z")
There was some discussion previous about the lack of a bat-9 to work with 9-8v as bat-6 works with 6-12v. Is there interest in a high end monitor that works with lead acid? Possible flash back to lithium bms for future conversion. Here is my second test of bms conversion to lead acid monitor. Connected to two over charged 12v batteries. 3 wire connection. Common and 1 wire to each 12v. also works on 9 X 8v. This is a hardware fix. Does not display individual 12v battery voltages. Sum of first 4 = 12v #1 battery. Obviously this is not ready for prime time. However: Total voltage Battery level Amps charge Amps discharge kwh in Kwh out All displayed properly. Coming soon ammeter scale displayed similar to battery level in bottom picture. Connection from battery area via standard phone handset wire. If interest I may be able to get it in production quickly. It only takes money. Est. msrp $300 I can make one now for an eager user. All works except cell voltages are split in 4 segments do to current sw limitations. Proof of concept only. ![](https://canada1.discourse-cdn.com/flex030/uploads/electricforum/original/2X/4/40082db8701f12a2c92a54523f577c8458c5b2e0.JPG) ![](https://canada1.discourse-cdn.com/flex030/uploads/electricforum/original/2X/d/dcaf49b1dc2cc6b0cd79f992067e637674369d27.JPG) ![](https://canada1.discourse-cdn.com/flex030/uploads/electricforum/original/2X/6/66daa85374a330efe819b08cbc54bf25569fd5d4.JPG) ---
**Author:** ![Big\_Dee](https://avatars.discourse-cdn.com/v4/letter/b/9fc348/32.png) [@Big\_Dee](https://community.electricforum.com/u/Big_Dee)\ **Post date:** [July 22, 2017, 12:51pm UTC](https://community.electricforum.com/t/high-end-battery-monitor-lead-acid-2-to-9-batteries/12598/2 "2017-07-22T12:51:20Z")
I would be interested in Bat-9. I do not know size of market as 9-8VDC gels did not seem that popular. 6-12VDC seems to have been a lot more popular, due ease of finding 12VDC deep cycle batteries? Thanks you for putting forth effort. Cost benefit of monitoring batteries reduces battery replacement costs. I have 10,000 miles on original 9-8VDC batteries and still going strong, ---
**Author:** ![Inwo](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/inwo/32/1067_2.png) [@Inwo](https://community.electricforum.com/u/Inwo)\ **Post date:** [July 22, 2017, 2:29pm UTC](https://community.electricforum.com/t/high-end-battery-monitor-lead-acid-2-to-9-batteries/12598/3 "2017-07-22T14:29:39Z")
Thank you for reply. This would be a universal product. Monitor a wide range of systems. It is much more than a voltage monitor. Monitoring current use while motoring, WH into battery during charge and out while in use. Motor and controller temperature if connected. Final version would display each battery voltage and differential. As it is an existing product, large appeal is not needed and time to produce might be only weeks. Dave ---
**Author:** ![jm1361](https://avatars.discourse-cdn.com/v4/letter/j/7ea924/32.png) [@jm1361](https://community.electricforum.com/u/jm1361)\ **Post date:** [December 20, 2018, 8:03pm UTC](https://community.electricforum.com/t/high-end-battery-monitor-lead-acid-2-to-9-batteries/12598/4 "2018-12-20T20:03:02Z")
Did you ever build the bat -9 are you selling it I may have some interest ---
**Author:** ![Inwo](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/inwo/32/1067_2.png) [@Inwo](https://community.electricforum.com/u/Inwo)\ **Post date:** [December 20, 2018, 9:21pm UTC](https://community.electricforum.com/t/high-end-battery-monitor-lead-acid-2-to-9-batteries/12598/5 "2018-12-20T21:21:03Z")
Not enough interest. Are you looking to monitor 8 x 9v? There is a bluetooth app that can monitor up to 10 batteries on smart phone. The hardware gets expensive for 8 batteries. Made for someone with a lot of starter batteries to keep an eye on. Each battery is named in the app. and displayed on screen. ---
**Author:** ![jm1361](https://avatars.discourse-cdn.com/v4/letter/j/7ea924/32.png) [@jm1361](https://community.electricforum.com/u/jm1361)\ **Post date:** [December 21, 2018, 2:48am UTC](https://community.electricforum.com/t/high-end-battery-monitor-lead-acid-2-to-9-batteries/12598/6 "2018-12-21T02:48:45Z")
yes i am what do call expensive ---
**Author:** ![Inwo](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/inwo/32/1067_2.png) [@Inwo](https://community.electricforum.com/u/Inwo)\ **Post date:** [December 21, 2018, 3:08am UTC](https://community.electricforum.com/t/high-end-battery-monitor-lead-acid-2-to-9-batteries/12598/7 "2018-12-21T03:08:29Z")
The acquisition boards are about $50 per battery. The cheap ones are about $20 but only seem to do one battery at a time. ![image](https://canada1.discourse-cdn.com/flex030/uploads/electricforum/original/2X/b/bfaaadc41948124201a1522d77e45cce13d9f265.jpeg) I believe there are those that can modify the app to do more. ---
**Author:** ![jm1361](https://avatars.discourse-cdn.com/v4/letter/j/7ea924/32.png) [@jm1361](https://community.electricforum.com/u/jm1361)\ **Post date:** [December 21, 2018, 9:14am UTC](https://community.electricforum.com/t/high-end-battery-monitor-lead-acid-2-to-9-batteries/12598/8 "2018-12-21T09:14:42Z")
So that’s $120 plus the app, or $450 plus the app The cheaper one is doable, do mean I can only see one battery at a time or all 9 at once could you give me a website where I can get more info would surely appreciate ---
**Author:** ![Inwo](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/inwo/32/1067_2.png) [@Inwo](https://community.electricforum.com/u/Inwo)\ **Post date:** [December 21, 2018, 3:48pm UTC](https://community.electricforum.com/t/high-end-battery-monitor-lead-acid-2-to-9-batteries/12598/9 "2018-12-21T15:48:12Z")
I ordered a couple to test and asked company how the app works. Found them as low as $13.xx plus shipping somewhere. Search walmart online. Amazon may have reviews. The app is near impossible to find. See if this works. Not much functionality without the device. [http://measurement-ltd.com/supports-downloads.html](http://measurement-ltd.com/supports-downloads.html) | Item | Qty | Total | | --- | --- | --- | | [Bluetooth 12V Battery Monitor, iOS & Android Compatible- Accutire# MS-51](https://www.walmart.com/ip/692312761) | | | | **$18.28** | 2 | $36.56 | | Items may arrive in multiple boxes on different days. | | | ---
**Author:** ![Inwo](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/inwo/32/1067_2.png) [@Inwo](https://community.electricforum.com/u/Inwo)\ **Post date:** [December 27, 2018, 2:28am UTC](https://community.electricforum.com/t/high-end-battery-monitor-lead-acid-2-to-9-batteries/12598/10 "2018-12-27T02:28:11Z")
Got two in today. It does work, but app is optimized for starting batteries. Works down below 6 volts but has distracting warnings about low battery. Reported to work with 8 batteries. Have not found information on max devices. ![image](https://canada1.discourse-cdn.com/flex030/uploads/electricforum/original/2X/3/3ca699c78cbbe70a6c6dac8d3e014331d4464ed0.png) Can’t recommend for multiple batteries unless someone could rewrite the app. ---
**Author:** ![jm1361](https://avatars.discourse-cdn.com/v4/letter/j/7ea924/32.png) [@jm1361](https://community.electricforum.com/u/jm1361)\ **Post date:** [January 1, 2019, 3:56pm UTC](https://community.electricforum.com/t/high-end-battery-monitor-lead-acid-2-to-9-batteries/12598/11 "2019-01-01T15:56:51Z")
Thanks for info will try to find more info