Mike's Li-SAVER - RC-Monster Forums

**Mike's Li-SAVER -** 04.02.2008, 08:42 AM

I'm just about to order mike's li-saver. Question is how many cells can it handle? and what voltage does it cut off at?

jhautz · 04.02.2008, 09:12 AM

The Li-saver is good for 2-10 cells.

I dont see it in the documentation anywhere, but I believe it cuts off at 3.0v/cell.

04.02.2008, 05:39 PM

nice one...

has any had any issues with this save cutting out too low?

rchippie · 04.02.2008, 06:25 PM

Quote:

Originally Posted by andy85

I'm just about to order mike's li-saver. Question is how many cells can it handle? and what voltage does it cut off at?

I have used the lisaver on 4s with no problem at all.

04.03.2008, 09:26 AM

how does this li-saver react when voltage is low? total cut off or reduced power?

jhautz · 04.03.2008, 05:52 PM

Total cut off. going back to neutral resets it and you can move again to get it off the track, but you shouldnt drive after the cut out.

Arct1k · 04.03.2008, 05:59 PM

Nice - Would be a great feature to include with CC UBEC... option to cut power to RX...

04.04.2008, 10:46 AM

thanks for d input guys!!!

captain harlock · 04.04.2008, 05:24 PM

I'll definately get it for my Schulze controller.

kulangflow · 06:13 PM

Here's a question: Have any of you had problems with the li-saver cutting too early?

If I jump on the throttle, the truck jumps forward and immediately (violently) stops, which makes me think that the li-saver is cutting in.

The truck drives fine if I'm easier on the throttle (more gradual). If I bypass the li-saver, the truck acts like I expect it to and wheelies all the way down the road.

Are my batteries just dropping that much voltage that it trips the lvc, or is the lvc too sensitive or set too high?

Thoughts?

(Set-up: BL-Revo, MM, UBEC, 2 x 2s 6k lipos fully charged, Spektrum rx/tx)

Thanks!

jnev · 04.25.2008, 06:37 PM

If those 6000mah lipo's are the Max Amps ones, then they are probably the problem. They tend to drop their voltage without even a huge load on them.

kulangflow · 04.25.2008, 10:16 PM

Sure enough! I just got my EagleTree data and every time it hits 60 amps or greater, the voltage drops to 12V or below. To be a little fair though, they weren't freshly charged this time. They started at 3.9V/cell.

The peak current was 130A and that dropped the voltage to 9.1V. Yikes.

I have 4 total 2s 6K MaxAmps packs, so I'll have to test a few more combinations of them to see if I can narrow down one of them that might be causing the problem.

For this graph, I just averaged the voltages for everything under 110A.

jhautz · 04.25.2008, 10:36 PM

That'l do it. Glad to see you at least identified the problem.

I dont know if you have room, but try running 2 of those packs in parallel just to verify that a battery that holds voltage better solves the problem.

I think the reason the MM doesnt kick out is CC put a timer on the LVC in the MM. It needs to stay below the cut off voltage for a few seconds before it cuts out.

kulangflow · 04.25.2008, 07:08 PM

They definitely drop their voltage under load more than higher quality packs, but they were fresh off the charger at 16.8V. They can't be dropping that much voltage, can they? The same packs don't trip my MM's LVC.

I think I need to hook up my Eagle Tree to see what's happening when it cuts out like that.

Thanks again for your help.

jhautz · 04.25.2008, 08:28 PM

I remember having a similar problem when I first used that Lisaver. I was using 5s 8000mah 10C batteries in a heavy savage. I changed to better batteries and havent seen it since. I actually forgot about it until I read this post. The LiSaver seems to have a very hard cut off. If it touches 3.0v it shuts down.

I would be interested to see your eagle tree data though. I never did that... but probably should have looking back.