Question Burn Testing DPV?

[PEDiver]

Outside of just doing an in-water test, how do you burn test your DPV batteries? Resistor bank and voltmeter? Looking for a way to properly burn test my DPV at home with either a DIY solution or something off the shelf if a company makes a tester. I have a DiveX Piranha (non-PTB) but would also hope the tester works with other DPV models if I decided to upgrade/buy another.

 

[Whitrzac]

The last non ptb piranha is at least 5(?)+ years old. Chances are the battery is hosed.

They make 150w battery dischargeers that work fairly well, but you'll need to put you're own connectors on it and make sure it's set correctly

 

[PEDiver]

The last non ptb piranha is at least 5(?)+ years old. Chances are the battery is hosed.

They make 150w battery dischargeers that work fairly well, but you'll need to put you're own connectors on it and make sure it's set correctly

Yep I actually have two and they are from 2016. One is currently having its battery rebuilt and the other still holds charge and has a decent runtime. But only a matter of time until I'll have to rebuild the second one. But looking for a way to periodically test burn time without having to get it wet.

 

[DiveDay]

This is what one of my local dive shops uses, seems like overkill for personal use: PRECISION DC ELECTRONIC LOADS but it would work across brands.

Suex manufactures their own for their batteries: Burn Tester

Perhaps the easiest option would be if you owned something like a Genesis DPV where you can just run it down outside the water at full blast w/o damaging it.

 

[Whitrzac]

150W Electronic Load Voltmeter Ammeter Battery Capacity Discharge USB Tester New | eBay

It is more more flexible to use. - Built-in over current, over temperature and over power safety protection functions. - 1 x Electronic Load Tester. Fast speed and strong wind. No Bluetooth pairing is required.

www.ebay.com

 

[rjack321]

150W Electronic Load Voltmeter Ammeter Battery Capacity Discharge USB Tester New | eBay

It is more more flexible to use. - Built-in over current, over temperature and over power safety protection functions. - 1 x Electronic Load Tester. Fast speed and strong wind. No Bluetooth pairing is required.

www.ebay.com

The problem is this load is too small to get the voltage to drop like the actual scooter motor. So the low voltage cut off in the controller will potentially trip earlier on real dives. Burn testing is also really hard on NIMH batteries.

 

[Whitrzac]

The problem is this load is too small to get the voltage to drop like the actual scooter motor. So the low voltage cut off in the controller will potentially trip earlier on real dives. Burn testing is also really hard on NIMH batteries.

Its not for testing time to discharge, its for testing AH capacity of the pack vs what it was originally.

If the battery delivers significantly less capacity at 10-15a(typical dpv cruise draw) than it does at 5a, you're battery is hosed.

 

[rjack321]

Its not for testing time to discharge, its for testing AH capacity of the pack vs what it was originally.

If the battery delivers significantly less capacity at 10-15a(typical dpv cruise draw) than it does at 5a, you're battery is hosed.

The NIMH batteries will typically age differently across the pack so there will be one or two cells that drop out leading to a sudden drastic voltage drop. That causes the ESC to stutter at high loads but they limp along at slow speeds. This tester isnt going to be able to detect that kind of age related failure mode ahead of time.

Personally I would 1) just dive run the scooter in a tank or barrel at high speed or 2) go for a long dive at site where swimming home isnt a big deal.

 

[stuartv]

Personally I would 1) just dive run the scooter in a tank or barrel at high speed or 2) go for a long dive at site where swimming home isnt a big deal.

He's got two. He could just run out for half the expected burn time on one, then turn around and start coming back, while towing the other.

 

[PEDiver]

Personally I would 1) just dive run the scooter in a tank or barrel at high speed or 2) go for a long dive at site where swimming home isnt a big deal.

I may look more into option 1 since that will allow me more flexibility on running the DPV at different speeds for longer periods in a controlled environment. I guess the only downfall is not being able to account for gear factors (doubles + stages) but I can approximate and get some round numbers before a proper in-water test.