# GEM powered with (7) 12v gel batteries **URL:** \ **Category:** GEM Forum\ **Created:** [December 7, 2021, 11:41pm UTC](https://community.electricforum.com/t/gem-powered-with-7-12v-gel-batteries/23039 "2021-12-07T23:41:09Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![mdixon](https://avatars.discourse-cdn.com/v4/letter/m/22d042/32.png) [@mdixon](https://community.electricforum.com/u/mdixon)\ **Post date:** [December 7, 2021, 11:41pm UTC](https://community.electricforum.com/t/gem-powered-with-7-12v-gel-batteries/23039/1 "2021-12-07T23:41:10Z")
As the title reads, I have (7) Deka 8G31 batteries in my gem. Long story short, guy said I needed (6) 12v batteries when I really needed (9) 8v batteries. Nonetheless, it is what I have in there now. I have a Delta Q charger that I would like to reprogram to full charge all 7 batteries. Does anyone have any suggestions? ---
**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 7, 2021, 11:43pm UTC](https://community.electricforum.com/t/gem-powered-with-7-12v-gel-batteries/23039/2 "2021-12-07T23:43:51Z")
There are no profile for that in a 72v charger. You need an 84v deltaQ, which is somewhat rare. Worth your trouble though as it will boost performance and range. ---
**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 7, 2021, 11:44pm UTC](https://community.electricforum.com/t/gem-powered-with-7-12v-gel-batteries/23039/3 "2021-12-07T23:44:27Z")
Or what most do is use a 12v charger on the added battery. @Old_Houseboater ---
**Author:** ![JarJarJava](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/jarjarjava/32/15158_2.png) [@JarJarJava](https://community.electricforum.com/u/JarJarJava)\ **Post date:** [December 8, 2021, 2:04am UTC](https://community.electricforum.com/t/gem-powered-with-7-12v-gel-batteries/23039/4 "2021-12-08T02:04:25Z")
@mdixon Dude, don’t fret, your gem will love the extra voltage. The salesbag actually did you a favor with their frack up. More range and potentially more speed. All you need to do is mount he extra battery, install some extra battery cables to hook it up and depending how you connect it, possibly an 84 → 72v shunt on pin 1 of the controller. If that’s all you do, you will get more range and better acceleration. If you want more speed, you need a programmer or get a magic magnet from @Inwo, who usually also has the shunts if you need them. You can charge the extra battery with any basic 12V portable charger that is compatible with gel batteries. . Oh, and check your DQ to see that is is set for the proper profile for the six (6) 12V gels. Wrong profile = premature battery death. The links to how to do it: Rodney’s original thread: > [@84 Volt 2 Seater](https://community.electricforum.com/t/84-volt-2-seater/15470): > > A few weeks ago I stated that I intended to add a 7th battery to my 2002 two seater. This is the result. Three/four miles of extra range. Lots of acceleration. 42 MPH but limited to 38. The last 4 MPH EATS!!! range, True 22 miles range on turf mode flat ground.@ about 30 MPH TECHNICAL 2002 2 seater 8.9 gearbox 21" diameter fat tires on 10 inch rims (205 65 10) 7.5 RFF Black Motor (My Mods) INWO Spoof. (I asked INWO to make me a modified Spoof to allow 2 more volts thru to better balance contr… The thread where Dave and I went a bit over the top, but found a way to do it without the shunt and without having to disconnect the 7th battery to charge as we isolated it on the other side of the contactor from the main pack. > [@LiFePo4 "7th battery" on a lead bottom GEM](https://community.electricforum.com/t/lifepo4-7th-battery-on-a-lead-bottom-gem/16591): > > This was an idea that Dave @Inwo came up with at some point in the past and I was the first ̶i̶d̶i̶o̶t̶ scientific pioneer willing to test it… … Adding an extra battery after the main contactor, so that only the high amperage terminals on the controller see the extra voltage. Translation, no voltage shunt needed for control power and that somehow changes how the controller sees things and the car performs and I’m gonna let Dave explain that part because he’s an electronics genius and I just f… I used lifepo4 pack for #7 in that experiment, but others have been successful with the same wiring arrangement and traditional batteries ---
**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:** [December 8, 2021, 2:11am UTC](https://community.electricforum.com/t/gem-powered-with-7-12v-gel-batteries/23039/5 "2021-12-08T02:11:23Z")
I think there is an easier way. I have thought about moving the positive charger wire from psdm to the #6 positive battery. The charger would then only charge 1-6. Then put the other batteries after #6 with dedicated chargers. Gauge on dash wouldn’t work but I think batteries would charge fine. ---
**Author:** ![AssyRequired](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/assyrequired/32/7621_2.png) [@AssyRequired](https://community.electricforum.com/u/AssyRequired)\ **Post date:** [December 8, 2021, 2:53am UTC](https://community.electricforum.com/t/gem-powered-with-7-12v-gel-batteries/23039/6 "2021-12-08T02:53:28Z")
@mdixon - Hey! I was wondering what happened to you. Last I remember you were off and getting your motor rebuilt. ---
**Author:** ![mdixon](https://avatars.discourse-cdn.com/v4/letter/m/22d042/32.png) [@mdixon](https://community.electricforum.com/u/mdixon)\ **Post date:** [December 8, 2021, 3:14am UTC](https://community.electricforum.com/t/gem-powered-with-7-12v-gel-batteries/23039/7 "2021-12-08T03:14:47Z")
Alright, lots of information to digest. My 72v is on the correct profile, I made sure of that when installing the initial 6. So it’s either upgrade my charger to an 84v or connect the one battery to a separate charger. Dumb question, so I would need to disconnect that battery from the cycle and bypass it each charge? I found an 84v charger for $500, what’s the going rate for a used 72v charger? I also need Hood and trunk/bumper/bed for it (2014 e6) if anyone knows where one is. ---
**Author:** ![JarJarJava](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/jarjarjava/32/15158_2.png) [@JarJarJava](https://community.electricforum.com/u/JarJarJava)\ **Post date:** [December 8, 2021, 4:50am UTC](https://community.electricforum.com/t/gem-powered-with-7-12v-gel-batteries/23039/8 "2021-12-08T04:50:26Z")
> [@mdixon](#): > > Dumb question, so I would need to disconnect that battery from the cycle and bypass it each charge? Depends how and where you connect it. Each of the three methods have the battery wired up in a different location on the circuit. I recall that Rodney’s original method required you to disconnect the 7th battery for charging. If you follow the wiring diagram from Dave that is posted in my thread, you can leave everything connected. LithiumGods suggested method should also work without disconnecting anything, You will need a voltage shunt on the controller harness connector for this wiring arrangement. ---
**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:** [December 8, 2021, 2:14pm UTC](https://community.electricforum.com/t/gem-powered-with-7-12v-gel-batteries/23039/9 "2021-12-08T14:14:33Z")
> [@84 volt instalation in pictures](https://community.electricforum.com/t/84-volt-instalation-in-pictures/18970): > > 84 volt install in my 2000 e825 4 seater. What say you?