# 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:** 1\ **Showing post:** 4
**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 --- _[View the full topic](https://community.electricforum.com/t/gem-powered-with-7-12v-gel-batteries/23039)._