Lithium Conversion on 2006 e4

The traditional Gel batteries are up for replacement on our 2006 e4 and are failing to hold a charge so I’m looking at lithium replacement options. I’m not an electrician but am somewhat handy if I have enough information or guides to assist so I’m not opposed to a DIY job.

I ran across the 72v 40ah kit online which peaked my interest. Any experience with these?

I have the DeltaQ charger onboard now and assume I need to replace it. Are there other items that need rewiring (harnesses, etc?) or reprogramming? It can’t be as easy as swapping out batteries and chargers is it?


$3900, ouch.

If you don’t mind a little minor wiring work and a little custom fitting, pretty sure Dave @Inwo could set you up with a 60Ah lifepo4 set that would give you more voltage (= more speed, lots more in some cases) and decent range for a lot less.

I was able to get a complete volt pack for $2300 delivered. That’s enough battery modules for two high voltage GEMs. Charger reprogram and a few odds and ends and I’m in for well less than $2000 for my half. Much faster and longer range. Pretty easy diy job. There’s a ton of info on this forum.

I deeply regret not getting an entire volt pack like you did. I ended up buying them in chunks and probably spent more over the long run.

40ah is not going to be enough unless you are only looking for a couple miles of range tops.

where are you located ? can get you into a lithium set up for under $1500 . between 25- 30 mile range .
Or the super deluxe high range set up for 3k . 4x more capacity then the link you posted . Good chance you wont have to buy a new charger . We are here to help .


@Inwo LiFePO4 25 cell set ups are great in my 2002 e825. Easily under $1700 shipped. Simple install - goodbye lead acid.

1 Like

@cbepps 25s battery with balance boards are boxed up and ready for ups to drag behind their truck. :sweat_smile:

Half filled at the same time first try.<1ah topped the rest off.
Took out about 30ah for shipping. Can’t wait to see how the stock charger works.
@LithiumGods for setting.

Thanks, @Inwo and others (@LithiumGods and @Reddevil) for feedback and insight thus far. It helped with the decision. I started getting the car prepped last night for when these get delivered. Looking forward to the conversion and longer term value of the lithium. I’ll make sure to post results and info here on my progress seeing that my perspective is that of a beginner hobbyist.

Hopefully I’m not jumping the shark but I found another project car, an '03 e4, that I’m heading to look at this weekend. Safe to say I’m hooked.

Could I get more info on this set up my email is