# Battery discharge indicator question **URL:** \ **Category:** GEM Forum\ **Created:** [March 30, 2020, 6:24pm UTC](https://community.electricforum.com/t/battery-discharge-indicator-question/18407 "2020-03-30T18:24:49Z")\ **Posts on this page:** 12\ **Page:** 1
**Author:** ![IRBGEM](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/irbgem/32/4550_2.png) [@IRBGEM](https://community.electricforum.com/u/IRBGEM)\ **Post date:** [March 30, 2020, 6:24pm UTC](https://community.electricforum.com/t/battery-discharge-indicator-question/18407/1 "2020-03-30T18:24:49Z")
Typically I charge my batteries (6mos old 31s) after every drive. I have noticed something that hopefully someone here can help me understand. I just drove 3.6 miles and the indicator was down to showing 84%. I got home and checked the cables (one was hot, looks like a bad connection) and test voltage (all were right around 12.8). I turned the car on about three minutes later and the BDI showed 100%. What am I missing? Why the large drain after less than 4 miles and why the sudden jump from 84% to 100%? Edit: Batteries started at 13.2. All flat ground, no hills. ---
**Author:** ![grantwest](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/grantwest/32/15_2.png) [@grantwest](https://community.electricforum.com/u/grantwest)\ **Post date:** [March 31, 2020, 11:54am UTC](https://community.electricforum.com/t/battery-discharge-indicator-question/18407/2 "2020-03-31T11:54:00Z")
The Battery Gauge or SOC “State of Charge” Meter on your dash will do exactly what you found out it’s totally normal. Example you drive to a location starting with a full pack 100%. Let’s say you drive 5 miles you pack shows 90%. You stop “go in and get a drink” come back and put the key in “Poof” Magic! suddenly your back to 100% Yes unfortunately this is (Fake Battery News) you will find out that after your flooded Acid battery’s rested the voltage creeps up and they gave your cars SOC a false Reading. You will find out that as soon as you start driving that 100% will quickly return back to 90% Yes it’s great that you found the loose cable. Consider yourself lucky. That’s a great way to burn up a battery. But unfortunately voltage sag is a part of the flooded lead acid game. Just keep a eye on it and only use your SOC gauge as a suggestion of actual range left. Don’t count on that Gauge to be super accurate after a prolonged rest. ---
**Author:** ![grantwest](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/grantwest/32/15_2.png) [@grantwest](https://community.electricforum.com/u/grantwest)\ **Post date:** [March 31, 2020, 11:57am UTC](https://community.electricforum.com/t/battery-discharge-indicator-question/18407/3 "2020-03-31T11:57:41Z")
I think the SOC gauge is most accurate right after you stop. Just after putting a load on your battery’s stop look at the gauge. That’s a pretty accurate indication of actual Battey strength. ---
**Author:** ![IRBGEM](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/irbgem/32/4550_2.png) [@IRBGEM](https://community.electricforum.com/u/IRBGEM)\ **Post date:** [March 31, 2020, 12:05pm UTC](https://community.electricforum.com/t/battery-discharge-indicator-question/18407/4 "2020-03-31T12:05:33Z")
As always, thank you @grantwest for the help. ---
**Author:** ![Monkeyron](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/monkeyron/32/6634_2.png) [@Monkeyron](https://community.electricforum.com/u/Monkeyron)\ **Post date:** [April 11, 2020, 9:07pm UTC](https://community.electricforum.com/t/battery-discharge-indicator-question/18407/5 "2020-04-11T21:07:59Z")
I’m tuning up a 07 e4 to sell. The 8G31 gels all tested good. Fully charge up. Take it for a ride up and down around my hilly neighborhood. 2 miles and 1 bar down then it drops to 1 red bar and Turtles. 73-74 vdc at the controller with 2 different DVMs. Load test all batteries (Carbon tester Harbor Freight) all but 1 shows 12vdc analog. 1 battery was lower on load than the rest. Turn the key on, still 1 red bar at 74vdc? What your thoughts @grantwest @Inwo @Old_Houseboater ---
**Author:** ![Monkeyron](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/monkeyron/32/6634_2.png) [@Monkeyron](https://community.electricforum.com/u/Monkeyron)\ **Post date:** [April 11, 2020, 11:16pm UTC](https://community.electricforum.com/t/battery-discharge-indicator-question/18407/6 "2020-04-11T23:16:35Z")
On my e6, the dash will not show any battery level. Shows 82 then it shows 81 and wrench. @Inwo @grantwest@Old_Houseboater ---
**Author:** ![Old\_Houseboater](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/old_houseboater/32/544_2.png) [@Old\_Houseboater](https://community.electricforum.com/u/Old_Houseboater)\ **Post date:** [April 11, 2020, 11:59pm UTC](https://community.electricforum.com/t/battery-discharge-indicator-question/18407/7 "2020-04-11T23:59:21Z")
In a message dated 4/11/2020 7:30:07 PM Eastern Standard Time, [electricforum@discoursemail.com](mailto:electricforum@discoursemail.com) writes: ---
**Author:** ![Old\_Houseboater](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/old_houseboater/32/544_2.png) [@Old\_Houseboater](https://community.electricforum.com/u/Old_Houseboater)\ **Post date:** [April 12, 2020, 12:02am UTC](https://community.electricforum.com/t/battery-discharge-indicator-question/18407/8 "2020-04-12T00:02:06Z")
Do a brake on load test of each battery. I . think you might find a dud with a bad cell. Remember all connections bright and tight. 1 corroded connection can through you for a loop In a message dated 4/11/2020 7:30:07 PM Eastern Standard Time, [electricforum@discoursemail.com](mailto:electricforum@discoursemail.com) writes: ---
**Author:** ![Monkeyron](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/monkeyron/32/6634_2.png) [@Monkeyron](https://community.electricforum.com/u/Monkeyron)\ **Post date:** [April 12, 2020, 4:23am UTC](https://community.electricforum.com/t/battery-discharge-indicator-question/18407/9 "2020-04-12T04:23:20Z")
All are bright and tight. Charging and seen 3 bars then 100%. No progress just 30% to done. Driving 90% then to 10% turtle. 74.2 vdc at controller showing 10% on dash. 1 battery is lower and slower to charge but the display is weird. ---
**Author:** ![LithiumGods](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/lithiumgods/32/672_2.png) [@LithiumGods](https://community.electricforum.com/u/LithiumGods)\ **Post date:** [April 12, 2020, 12:46pm UTC](https://community.electricforum.com/t/battery-discharge-indicator-question/18407/10 "2020-04-12T12:46:39Z")
put your volt meter on your controller and run it . you need to see what the voltage is just as it goes into turtle , not after . I think 65v triggers turtle and 60v is controller shut off . ---
**Author:** ![Monkeyron](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/monkeyron/32/6634_2.png) [@Monkeyron](https://community.electricforum.com/u/Monkeyron)\ **Post date:** [April 12, 2020, 4:07pm UTC](https://community.electricforum.com/t/battery-discharge-indicator-question/18407/11 "2020-04-12T16:07:08Z")
I have a few new 200 volt amp digital displays that I was going to connect to the contactor out. I think they will fit right of the glove box. What I find weird is the dash showing 30 % then done at charging? Same when master off 30 seconds then on showing still showed 10% while 74.1 at the controller? Checking connections at the dash leads at the contactor. But I don’t believe that effects the Turtle mode. ---
**Author:** ![LithiumGods](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/lithiumgods/32/672_2.png) [@LithiumGods](https://community.electricforum.com/u/LithiumGods)\ **Post date:** [April 12, 2020, 6:07pm UTC](https://community.electricforum.com/t/battery-discharge-indicator-question/18407/12 "2020-04-12T18:07:15Z")
Your dash probably needs recalibration