Helix 7/Lithium Shuttle Voltage Question

So I got a Marcum Lithium Shuttle for my Helix 7 this year. I mounted the Helix and soldered the adapter to a Humminbird power cord. Powers up great right away.

I’ve seen other posts about the battery percentage discrepancy which is fine with me but I’m noticing that the battery meter on my Helix goes from full to 20% within two hours. The shuttle will still show 85%+. The problem is that when the Helix meter gets that low it’s saying it’s around 11.5v (+/- 0.3v). When it’s full, it’s around 12.3v. I thought that lithium batteries give full output until discharged? The voltage will also drop if I plug my phone in to charge or turn on the built in LED light. When it drops that low I feel I notice more interference on my flasher.

Is it normal to see the voltage levels dropping into the 11.2-11.8v range when the shuttle still says it’s at 85%+? I’ve never used a lithium battery before and this is my first season using my Helix on the ice so not sure if this is normal and expected or if something is faulty.

I know guys have run into problems with the marcum shuttle and the battery in it. No issues with a better battery like an amped or Dakota. It reads 100 percent until it dies.

I am having the exact same issues with mine. (I did not do any soldering) Plan to use it a few more times, as I hope this was a fluke this time.

As mentioned the battery percentage left on the Helix unit is no longer accurate with a Lithium. You have to go by voltage on the unit.

The Amped’s in my Helix and Panoptix start off at 14.4-14.5v then will slowly drop to 13.5-13.3v and then stay there for hours.

At 11.5v the units shut off. Party is over.

The runtime in the panoptix is 24hrs from full charge to dead. No idea on my Helix as I’ve never did a runtime experiment.

I’m using my Helix for the voltage readings but I feel the voltage readings you’re getting are what I should be getting when it’s fully charged. Not 12.3v. I’ll have to contact Marcum and maybe the store I bought it from. Problem is that I had to tap holes to mount my Helix 7 so probably can’t just return or exchange for a new unit…

I had same problem checked actual voltage from shuttle with helix on and shuttle fresh off charger at 100% voltage only 11.7 volts. Pulled helix off shuttle put on amped outdoors lithium. No more issues.

That’s what I’m afraid of. I used my voltmeter and checked and my Helix is spot on at 12.3v with the shuttle fresh off the charger. Might be purchasing an Amped battery.

I know I won’t be able to return or exchange the shuttle. Has anyone opened it up and seen if you can fit an Amped battery in it?

https://marcumtech.com/product/lithium-shuttle-battery-replacement/ shows what the lithium battery in the shuttle looks like – no you can’t put a sla sized lithium in the shuttle

Thank you for that. That’s helpful because I don’t want to pop it open until I hear back from their customer service. I probably already voided my warranty by tapping the holes into the shuttle. If that’s the case I’ll pop it open and see if I can find a way to cleanly mount an Amped battery somehow. I like the shuttle itself but really wish I felt more confident with the battery.

BackwaterICE wrote:

https://marcumtech.com/product/lithium-shuttle-battery-replacement/ shows what the lithium battery in the shuttle looks like – no you can’t put a sla sized lithium in the shuttle

Interesting!

Thanks for the picture!

So it looks like that’s just a big 3 cell lipo Rc battery. I run 3 cell 11.1v lipos in my rc crawler so that’s My reason for saying this.

So that “should” fully charge to around 12.6 volts +\- and conservatively cutoff at 10.2 volts or so.

That clears a lot up about the marcum shuttle.

For the guys that have the Helix/shuttle combo I’d just run it and see what you can get out of it.

If a full day can be attained with no issues I wouldn’t worry.

It’s going to be a different experience than a 12v sla style battery.

That is just my thoughts. I could be way off.

They list the shuttle as 12.8v at full charge. I’m only getting 12.3v. It lasts a long time and still runs the Helix. I tested it and it was still working after 8hrs. The shuttle was still showing 70%. The problem for me at least, has been when it starts draining I get interference showing up on my flasher. I think it’s due to the lower voltage not being able to power the Helix properly. My old LX9 got bad interference when the battery was drained.

I am tempted to take my shuttle apart and see if there is some kind of resister/voltage regulator in there that could be bypassed. or if a 9ah milwaukee drill battery and adapter would fit.