# Gem e2, 2 seater 2002 E825 Lithium Upgrade(tighter fit) **URL:** \ **Category:** GEM Forum\ **Created:** [February 10, 2017, 7:15pm UTC](https://community.electricforum.com/t/gem-e2-2-seater-2002-e825-lithium-upgrade-tighter-fit/12042 "2017-02-10T19:15:48Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![nakedwaterskier](https://avatars.discourse-cdn.com/v4/letter/n/258eb7/32.png) [@nakedwaterskier](https://community.electricforum.com/u/nakedwaterskier)\ **Post date:** [February 10, 2017, 7:15pm UTC](https://community.electricforum.com/t/gem-e2-2-seater-2002-e825-lithium-upgrade-tighter-fit/12042/1 "2017-02-10T19:15:48Z")
The 2 Seater Gem car does not have the room to make it easy like the 4 seater to upgrade to lithium. I have lots of pics for those that want to attempt it. It came with the old Zivan charger which according to their main Sacramento location can be reprogrammed though I haven’t done it yet. ![](https://canada1.discourse-cdn.com/flex030/uploads/electricforum/original/1X/7eab69a9767929500b8575d1542968b4491ef38d.jpg) ---
**Author:** ![nakedwaterskier](https://avatars.discourse-cdn.com/v4/letter/n/258eb7/32.png) [@nakedwaterskier](https://community.electricforum.com/u/nakedwaterskier)\ **Post date:** [February 10, 2017, 7:18pm UTC](https://community.electricforum.com/t/gem-e2-2-seater-2002-e825-lithium-upgrade-tighter-fit/12042/2 "2017-02-10T19:18:28Z")
![](https://canada1.discourse-cdn.com/flex030/uploads/electricforum/original/1X/74123c0f16fe8f2641bd2bf044118beaa90e549f.jpg) FRONT COMPARTMENT ---
**Author:** ![nakedwaterskier](https://avatars.discourse-cdn.com/v4/letter/n/258eb7/32.png) [@nakedwaterskier](https://community.electricforum.com/u/nakedwaterskier)\ **Post date:** [February 10, 2017, 7:21pm UTC](https://community.electricforum.com/t/gem-e2-2-seater-2002-e825-lithium-upgrade-tighter-fit/12042/3 "2017-02-10T19:21:24Z")
Under the seat; much tighter than 4 seater setup. 5 LEAF MODULES UPFRONT IN SERIES, 3 MORE UNDER SEAT IN SERIES AND 4 IN PARALLEL ![](https://canada1.discourse-cdn.com/flex030/uploads/electricforum/original/1X/680aae0d7af9cf6d577004d5321440ee05a583ed.jpg). I used plexiglass and bender board to secure them… ![](https://canada1.discourse-cdn.com/flex030/uploads/electricforum/original/1X/3429586fcb18dc41d00cc62e3dc28e250c4f01e1.jpg) ---
**Author:** ![nakedwaterskier](https://avatars.discourse-cdn.com/v4/letter/n/258eb7/32.png) [@nakedwaterskier](https://community.electricforum.com/u/nakedwaterskier)\ **Post date:** [February 10, 2017, 7:28pm UTC](https://community.electricforum.com/t/gem-e2-2-seater-2002-e825-lithium-upgrade-tighter-fit/12042/4 "2017-02-10T19:28:22Z")
![](https://canada1.discourse-cdn.com/flex030/uploads/electricforum/original/1X/b57b115a21e0714ffd8e554222233c40bce53543.jpg) Leaf modules were from a 2013 model with 45,000 miles on them. Nissan was sued and had to settle over the lack of range/weak battery pack on the 2012 and earlier battery pack. I STILL HAVE LEFT OVER CELLS I WILL PROBABLY END UP SELLING. This was the reading after installation before I ever drove or charged the cells ie the Leaf modules were in great shape. ---
**Author:** ![nakedwaterskier](https://avatars.discourse-cdn.com/v4/letter/n/258eb7/32.png) [@nakedwaterskier](https://community.electricforum.com/u/nakedwaterskier)\ **Post date:** [February 10, 2017, 7:29pm UTC](https://community.electricforum.com/t/gem-e2-2-seater-2002-e825-lithium-upgrade-tighter-fit/12042/5 "2017-02-10T19:29:07Z")
![](https://canada1.discourse-cdn.com/flex030/uploads/electricforum/original/1X/a413203baeb2c4a546a0ed3719ed51419817605a.jpg) Front connections view. 5 Leaf Modules fit perfectly without endplates though. The bottom of the battery compartment is nicely/well insulated. I LEFT 2 DISCONNECTED TROJANS IN FOR BALLAST. 1 UNDER THE SEAT AND 1 IN THE FRONT COMPARTMENT. NOBODY HAS FOUND AFTERMARKET SHOCKS THE CORRECT DIMENSIONS? ---
**Author:** ![nakedwaterskier](https://avatars.discourse-cdn.com/v4/letter/n/258eb7/32.png) [@nakedwaterskier](https://community.electricforum.com/u/nakedwaterskier)\ **Post date:** [February 10, 2017, 7:40pm UTC](https://community.electricforum.com/t/gem-e2-2-seater-2002-e825-lithium-upgrade-tighter-fit/12042/6 "2017-02-10T19:40:59Z")
[http://vid943.photobucket.com/albums/ad278/halgot1/20170208\_145843\_zpswnj1ao8e.mp4](http://vid943.photobucket.com/albums/ad278/halgot1/20170208_145843_zpswnj1ao8e.mp4) PROOF OF CONCEPT. MAKE SURE THE DOG IS LOCKED UP! Dogs love Gem cars though they sometimes try to bite the front tire. Had to keep her away from the exposed battery pack; would have singed her hair big time! ---
**Author:** ![nakedwaterskier](https://avatars.discourse-cdn.com/v4/letter/n/258eb7/32.png) [@nakedwaterskier](https://community.electricforum.com/u/nakedwaterskier)\ **Post date:** [February 10, 2017, 7:42pm UTC](https://community.electricforum.com/t/gem-e2-2-seater-2002-e825-lithium-upgrade-tighter-fit/12042/7 "2017-02-10T19:42:32Z")
Still have to get BMS and Charger setup. ![](https://canada1.discourse-cdn.com/flex030/uploads/electricforum/original/1X/680aae0d7af9cf6d577004d5321440ee05a583ed.jpg) ---
**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:** [February 10, 2017, 10:07pm UTC](https://community.electricforum.com/t/gem-e2-2-seater-2002-e825-lithium-upgrade-tighter-fit/12042/8 "2017-02-10T22:07:12Z")
If I understand correctly, you have 120ah batteries in series with 60ah batteries? If, yes. What is your thoughts, or purpose? ---
**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:** [February 10, 2017, 10:09pm UTC](https://community.electricforum.com/t/gem-e2-2-seater-2002-e825-lithium-upgrade-tighter-fit/12042/9 "2017-02-10T22:09:55Z")
Much better to use Leaf cells for ballast. IMO With 20 total, you could have a 120ah pack rather than 60ah. ---
**Author:** ![nakedwaterskier](https://avatars.discourse-cdn.com/v4/letter/n/258eb7/32.png) [@nakedwaterskier](https://community.electricforum.com/u/nakedwaterskier)\ **Post date:** [February 10, 2017, 10:39pm UTC](https://community.electricforum.com/t/gem-e2-2-seater-2002-e825-lithium-upgrade-tighter-fit/12042/11 "2017-02-10T22:39:50Z")
I mean 8 in series, 4 in parallel ![](https://canada1.discourse-cdn.com/flex030/uploads/electricforum/original/1X/680aae0d7af9cf6d577004d5321440ee05a583ed.jpg) On Fri, Feb 10, 2017 at 2:38 PM, Gillette Jeffrey[nakedwaterskier@yahoo.com](mailto:nakedwaterskier@yahoo.com) wrote: 20 on series then 4 in parallel…keeps voltage the same but more current NOTICE I TRIED TO WHITE OUT THE LAST S! Sorry, been taking many antihistamines; bad allergies lately. ---
**Author:** ![nakedwaterskier](https://avatars.discourse-cdn.com/v4/letter/n/258eb7/32.png) [@nakedwaterskier](https://community.electricforum.com/u/nakedwaterskier)\ **Post date:** [February 10, 2017, 10:51pm UTC](https://community.electricforum.com/t/gem-e2-2-seater-2002-e825-lithium-upgrade-tighter-fit/12042/12 "2017-02-10T22:51:36Z")
I might use 20 cells ie 2x10 w an a vs b battery switch but then i would need a more expensive bigger bms…same if i do the 2 x 10 series packs in parallel…bigger bms and bigger charger…i can always reconfigure…but mine is only a 2 seater. ---
**Author:** ![nakedwaterskier](https://avatars.discourse-cdn.com/v4/letter/n/258eb7/32.png) [@nakedwaterskier](https://community.electricforum.com/u/nakedwaterskier)\ **Post date:** [February 10, 2017, 10:53pm UTC](https://community.electricforum.com/t/gem-e2-2-seater-2002-e825-lithium-upgrade-tighter-fit/12042/13 "2017-02-10T22:53:16Z")
The test drive was 10 in series but not what i ended up running ---
**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:** [February 10, 2017, 11:41pm UTC](https://community.electricforum.com/t/gem-e2-2-seater-2002-e825-lithium-upgrade-tighter-fit/12042/14 "2017-02-10T23:41:31Z")
> [@nakedwaterskier](#): > > I mean 8 in series, 4 in parallel I hate to disillusion you, but it doesn’t work that way.🙂 No good can come from that configuration. Possibly no harm either, just not a good idea. IMO Picture adding a 12v battery to only one of the Gem batteries. It works, but is unbalanced. Meaning, charging and discharging thru the string is thrown off. No way to keep in balance or to use the extra energy. Same bms for 20s no matter how many are in parallel. See picture of a typical leaf configuration. 2 in-series pairs in parallel. Adding more in parallel doesn’t change the number of cells to monitor or balance, as they are locked in step by electrical connection. I’m working now with a guy connecting 4 sets in parallel 24 in series. They are Volt batteries but same theory. He will have 200ah and 88v nominal. 100 volt peak. Using a single bms-24. ![](https://canada1.discourse-cdn.com/flex030/uploads/electricforum/original/1X/b081a164196a1d40b95d52268b5406cad53e03d8.gif) ---
**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:** [February 10, 2017, 11:48pm UTC](https://community.electricforum.com/t/gem-e2-2-seater-2002-e825-lithium-upgrade-tighter-fit/12042/15 "2017-02-10T23:48:05Z")
Here is how you double capacity with same cell count and voltage. Example 4 of 20. ![](https://canada1.discourse-cdn.com/flex030/uploads/electricforum/original/1X/62bc75cc4b04ad621ad2fd7950037917cb38e17f.gif) ---
**Author:** ![nakedwaterskier](https://avatars.discourse-cdn.com/v4/letter/n/258eb7/32.png) [@nakedwaterskier](https://community.electricforum.com/u/nakedwaterskier)\ **Post date:** [February 12, 2017, 7:07pm UTC](https://community.electricforum.com/t/gem-e2-2-seater-2002-e825-lithium-upgrade-tighter-fit/12042/16 "2017-02-12T19:07:53Z")
I will bounce it off my electrical engineer if he ever wakes up! ---
**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:** [February 12, 2017, 7:19pm UTC](https://community.electricforum.com/t/gem-e2-2-seater-2002-e825-lithium-upgrade-tighter-fit/12042/17 "2017-02-12T19:19:49Z")
Meanwhile don’t run it like that. Also, be careful not to parallel cells after this, as they will be out of balance. Make sure modules are within 100mv or so. When connecting unbalanced cells in parallel, current is only limited by connecting strap, and internal resistance. See if your engineer agrees. As always. IMHO ---
**Author:** ![nakedwaterskier](https://avatars.discourse-cdn.com/v4/letter/n/258eb7/32.png) [@nakedwaterskier](https://community.electricforum.com/u/nakedwaterskier)\ **Post date:** [February 12, 2017, 7:30pm UTC](https://community.electricforum.com/t/gem-e2-2-seater-2002-e825-lithium-upgrade-tighter-fit/12042/18 "2017-02-12T19:30:03Z")
I am afraid to go up to 88 Volts. I am set up 60 to 80V, 12x500= 6000W capacity; 88V to 100V would require more alterations to the Gem system? Stock is 72. ---
**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:** [February 12, 2017, 9:22pm UTC](https://community.electricforum.com/t/gem-e2-2-seater-2002-e825-lithium-upgrade-tighter-fit/12042/19 "2017-02-12T21:22:44Z")
With 20, 21, or 22, you don’t need a modification. Just charge a little over what Gem likes. It sags quickly. I finally had someone copy my 98v 24s setup. So far so good. Keep an eye on him in forum. Only issue was electric heater got too hot. I never use mine. It’s only the unbalanced system I take issue with. To work properly all series packs must be the same, or use separate bms and charging. Only way bulk charging works, is by dividing evenly between all packs in the series string. If one or two packs are greatly different capacity or voltage, it’s not good. If **all** packs in string are doubled it’s fine. ---
**Author:** ![nakedwaterskier](https://avatars.discourse-cdn.com/v4/letter/n/258eb7/32.png) [@nakedwaterskier](https://community.electricforum.com/u/nakedwaterskier)\ **Post date:** [February 12, 2017, 9:36pm UTC](https://community.electricforum.com/t/gem-e2-2-seater-2002-e825-lithium-upgrade-tighter-fit/12042/20 "2017-02-12T21:36:44Z")
Joe Engineer wants to read over the BMS manual before deciding what to do. He thinks bms might be able to be setup to compensate. ---
**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:** [February 12, 2017, 10:35pm UTC](https://community.electricforum.com/t/gem-e2-2-seater-2002-e825-lithium-upgrade-tighter-fit/12042/21 "2017-02-12T22:35:11Z")
See if this link works. Even if it can be compensated, there is no advantage to having the extra 2 modules. [https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=3&ved=0ahUKEwjxp8uvzovSAhXK7IMKHWLcD2MQFggqMAI&url=http%3A%2F%2Fwww.chargery.com%2Fdoc%2FChargery\_BMS24\_specification\_V1.0.pdf&usg=AFQjCNH7eWJZuafKn7-0HrSuT8JpOwYzAw&sig2=hP8SMv\_kvYJhjGhPZ8carg&cad=rja](https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=3&ved=0ahUKEwjxp8uvzovSAhXK7IMKHWLcD2MQFggqMAI&url=http%3A%2F%2Fwww.chargery.com%2Fdoc%2FChargery_BMS24_specification_V1.0.pdf&usg=AFQjCNH7eWJZuafKn7-0HrSuT8JpOwYzAw&sig2=hP8SMv_kvYJhjGhPZ8carg&cad=rja) [Next page](https://community.electricforum.com/t/gem-e2-2-seater-2002-e825-lithium-upgrade-tighter-fit/12042.md?page=2)