How to increase a Gem's range

One of the top questions I get asked is how to increase a Gem’s range . So I want to share a few ways to do it . Some are easy and cheap , some not .

  1. Increase the tire pressure . Most Gems I get in the tire pressure is low . Increasing it to 35psi will increase range and top speed . I did a test on flat ground . Gem had 21psi in the tires , increased it to 35 psi and picked up 2 mph .

  2. Keep your speed down , This is No fun but Gem’s are like cars . The faster you drive the lower your MPG or in this case , MIles per Kilowatt ?

  3. Increase it’s regenerative braking . Regenerative braking takes your speed and converts back into energy and puts it in your battery . Without it you are taking all that energy and wasting it on braking .Tesla’s have a lot of this programmed in and they call it one foot driving. Once you have it you don’t want to be without it . Gem has it but from the factory it is set on low . Also for you pre 2005 guys with crappy drum brakes , This will help slow you down and probably eliminate the need for a disc brake upgrade .

  4. When programming a controller keep #7 as high as possible . Reducing field current (#7) will increase a shunt motors top rpm . For those looking for more top speed you want to do this but it takes more amps from your battery . If you have all the top speed you need , Especially the lithium guys don’t reduce this number . On my personal gem I increased it . Because my Gem has high voltage lithium the top speed is more than i need so no reason to reduce #7 . If you drive your Gem and it surges at top speed your #7 is too low.

  5. Increase battery voltage . Raising your pack voltage increases speed and range . You can do the 7th battery hack for lead or add additional cells for lithium . If you have a 25s lithium pack increasing it to 26 , 27 or 28s will increase range . Don’t forget to increase the chargers voltage to compensate .

  6. Replace your batteries with higher amp hour ones . Lead and lithium come in higher capacities so when you put in new batteries put in bigger ones . The DeltaQ charger can handle them .

  7. Get the lead out ! The number one thing you can do to a Gem is lithium . It will make it faster ( with a stock motor 40mph is possible ) It will go farther , Mine is probably 50+ miles . And it will get much lighter . A stock pack with hardware weighs about 425 lbs . A lithium pack 85 to 150 lbs . A stock E4 weighs about 1200 lbs. Take out 300 lbs and you have removed 25% of its weight . That in itself makes it accelerate faster , handle better and stop much quicker . Add it with all the other benefits of lithium and it is the best thing you can do to a Gem .

Hope this helps some of you out . I always enjoy the comments .

Kinghappy , The Godfather of Lithium .


Good Info @LithiumGods !
I just acquired a 2011 E6 to flip. FS rebuilt the T4 and took the limits off. Checking the program later today. Any Suggestions while I’m in it?
7 hp and instead of the 9-8volts I installed 6-8G31 Deka gels. I’m thinking of adding the 7th to up the overall stats.
What are your thoughts?

You can add a 7th but you have to figure out how to charge it . The Gem will love it . FS might have locked your controller . Let us know if you can get in .

OH!? I will run out there now to see. Will be back to you shortly.

I could not connect to the FS controller. Tried changing ports with no luck

Can the DQ be reprogrammed for a 7th battery algorithm?

No you would need a 84v charger . @Inwo had a guy put a extra battery with dedicated charger right before controller and it worked .

I charge the first 6 batteries with the Zivan. for the 7th battery I have a small 6 amp mini charger with a read out. I plug both in at the same time. Always 100% in the morning

This is the thread Mike was referencing LiFePo4 "7th battery" on a lead bottom GEM

1 Like

@LithiumGods What are the setting for regen? I am swapping parts with my guy tomorrow and he’s bringing his controller.

decrease 19 and 20 . Try 100

@LithiumGods Cool, thank you.

Fyi , I turned regen to 1 once . Let off the gas and almost put my nose into the windsheild . I think there is a differnece in regen depneding on type of battery pack .

Bigger numbers equal less regen.

Which controller?

On a T2, 20 is not a regen setting.

Other regen settings on a T2:

I was refering to a T4 or T5 . Just looked at the T2 manual . It does it differently . It apprears you would raise 9 and 10 to increase regen amps . I have not done it with a T2 so cant be sure .

The t4/5 you can adjust amps but there is another setting that allows you to adjust the amount of regen . #19 &20

Thanks Mike. I’ll give those settings a try this weekend.

Thanks for the update. I guess I should have been more clear on what controller I have.

Well unfortunately, changing the #9 and #10 settings didn’t seem to make any difference or it was so minimal that it wasn’t noticed. I kind of saw this in the other threads. No one really mentioned any success. Thanks for looking into it I guess in the end though the T2 just isn’t going to do regen braking.

If the 7th is still in the series, how can the 72 volt charger can charge the 6 while the 7th is in the circuit? I do understand the dedicated charger wired to the 7th.