Logic Sentry DPV dashboard on BlackTip?

Please register or login

Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.

Benefits of registering include

  • Ability to post and comment on topics and discussions.
  • A Free photo gallery to share your dive photos with the world.
  • You can make this box go away

Joining is quick and easy. Log in or Register now!

stuartv

Seeking the Light
ScubaBoard Supporter
Scuba Instructor
Messages
11,805
Reaction score
8,457
Location
Lexington, SC
# of dives
500 - 999
I have a Dive-X BlackTip Tech scooter.

Does anybody know if the Logic Sentry dashboard will work in my scooter?

Is it plug-and-play or how much cutting/splicing would I have to do?

Will it show me the state of each individual power tool battery?

How much is the Sentry? I don't see any pricing on the Logic website.

I want to get a Genesis 3.1 eventually, and would want to have the Sentry on that. Until I can afford that, getting the Sentry to use on my BlackTip seems like a very useful thing and then I can move it over to the Genesis eventually.

I have had issues on a number of occasions with my BlackTip that I *think* are because of the batteries being out of balance. They are DeWalt 12 Ah packs that I bought new. I have only ever used them in my BlackTip and charged them at the same time in my DeWalt 4-bay charger (which I got, even though I only have the 2 batteries). So, in theory, they have exactly the same usage and charging cycles on them and shouldn't be out of balance. But, obviously, in the real world maybe one has a weak cell or something. I don't know. It seems like the Sentry could maybe help me figure that out.
 
so heres a few things.

The sentry is basically an external volt and ammeter. It will display the total voltage of the pack and how much current is being drawn. I don't know what connectors it comes with but Im sure you could ask @Jon Nellis to install some PP45s on them for use in the BT, you will need to unbond the Blue wire from the other connectors or make an extension as it still needs to be connected to the ESC.

It will not show you individual voltage as they are wired in series (this is what that blue wire does) and the BT ESC will make you aware if they are out of balance, So long as the batteries are used specifically for the DPV and charged on the same charger, balance should not be an issue.

from the Paragon site, the sentry is $780... Ouch and can be found here. I think for this use case and the cost of the BT it is a poor choice, especially since the BT already displays the information you are looking for.

If the batteries are truly out of balance and causing issues, do a dive, come back, remove both batteries and check their voltage with a voltmeter. if they are off, you could do a few things but that's for later discussion.
 
so heres a few things.

The sentry is basically an external volt and ammeter. It will display the total voltage of the pack and how much current is being drawn. I don't know what connectors it comes with but Im sure you could ask @Jon Nellis to install some PP45s on them for use in the BT, you will need to unbond the Blue wire from the other connectors or make an extension as it still needs to be connected to the ESC.

It will not show you individual voltage as they are wired in series (this is what that blue wire does) and the BT ESC will make you aware if they are out of balance, So long as the batteries are used specifically for the DPV and charged on the same charger, balance should not be an issue.

from the Paragon site, the sentry is $780... Ouch and can be found here. I think for this use case and the cost of the BT it is a poor choice, especially since the BT already displays the information you are looking for.

If the batteries are truly out of balance and causing issues, do a dive, come back, remove both batteries and check their voltage with a voltmeter. if they are off, you could do a few things but that's for later discussion.

Thanks, Jona.

I bought my DeWalt 12s together, at the same time, brand new. They have only ever been used in my BlackTip and charged on my DeWalt 4-bay charger. So, as you say, I think battery charge balance SHOULD not be an issue - and yet I've had it shut down several times while showing the battery 1 or 2 indicator on the screen. And, this has happened with my Travel and Tech tubes.

The info that they are in series and so the Sentry cannot show individual pack info seals the deal for me - against buying a Sentry. Well, that and the cost.... LOL

I think I just need to see if I can get DeWalt to replace them both under warranty before I mess with anything else.

Last question: What are the potential consequences of turning off the battery balance checking in the firmware?
 
The Sentry can sense the individual voltage of two batteries connected in series, up to 50V per battery and 100V total. That is why there is a V1 and V2 on the display. The original Genesis used two batteries in series and the Sentry was design around that and the fact that older lead acid DPVs used two batteries in series. You just need to have a sense wire coming from between the packs. It also has a water sensor on the internal transmitter. We have customers using them in SS and DX scooters, but I'm not aware of any used in BT. Chances are that you have a bad pack. I've had a few drill batteries go bad over the years. It happens.

Cheers,
Jon
 
The Sentry can sense the individual voltage of two batteries connected in series, up to 50V per battery and 100V total. That is why there is a V1 and V2 on the display. The original Genesis used two batteries in series and the Sentry was design around that and the fact that older lead acid DPVs used two batteries in series. You just need to have a sense wire coming from between the packs. It also has a water sensor on the internal transmitter. We have customers using them in SS and DX scooters, but I'm not aware of any used in BT. Chances are that you have a bad pack. I've had a few drill batteries go bad over the years. It happens.

Cheers,
Jon
The V Sense wire does not operate in the way you would expect.

2 18v batteries in series and the v sense wire will output ~1.2v. It has a voltage divider circuit to reduce the voltage to where the ADC on the ESC can read it.
 
https://www.shearwater.com/products/peregrine/

Back
Top Bottom