Tekna DV-3 Battery help

[yojreilly]

Hi
I just bought a Tekna DV-3X
I'm going to clean it up and install new o rings
I'm thinking about 4 Li-ion 18650 from all battery .com
each battery of the four battery's are 3.7 volt X 4 = 14.8 volts
each battery is 9.62 watt hours X4 = 38.48 watt hours

The old battery's were 12 v each and 17.5 amp hours each = 24 volt 35 amp hour

I'm not sure what I'm doing with the watt hours and amp hours

Also I have not heard back from All battery as to the size of the 18650 as to if it will fit in my battery compartment.

Has anyone installed these battery's in there Tekna ?

Or is there a better way to repower the Tekna

Thanks for any help

 

[Teknadv3x]

Hi
I just bought a Tekna DV-3X
I'm going to clean it up and install new o rings
I'm thinking about 4 Li-ion 18650 from all battery .com
each battery of the four battery's are 3.7 volt X 4 = 14.8 volts
each battery is 9.62 watt hours X4 = 38.48 watt hours

The old battery's were 12 v each and 17.5 amp hours each = 24 volt 35 amp hour

I'm not sure what I'm doing with the watt hours and amp hours

Also I have not heard back from All battery as to the size of the 18650 as to if it will fit in my battery compartment.

Has anyone installed these battery's in there Tekna ?

Or is there a better way to repower the Tekna

Thanks for any help

Ive owned several teknadv3x over the years...The best replacement I have found are the powersonic battires 12v 18AH.... run them in series= 24v 18.0 AH... remember the batteries when installed must help support the bulkheads to keep the scooter from imploding..a new set should give you a 60 minute runtime on a #6 pitch prop. 1 set should cost you around a $100.

Dave

 

[DA Aquamaster]

As noted above, the old batteries are two 12V batteries wired in series, so you need 24V for the motor to even notice it's connected to a battery.

There are lots of batteries around in that form factor, but weight and power delivery traits tend to vary, so I tend to stick with Powersonics. I like the Powersonic PSH-12180FR in the larger Mako scooter, but they are 1.2 pounds heavier per set than the PS-12180.

The first is a 21Ah battery while the latter is an 18Ah battery but the major difference is that the former allows for a higher discharge rate, and it's somewhat subjective but I seem to have a bit more power available on continuous scooter runs over about 30 minutes with the PSH-12180FR in my 1000 rpm Mako scooters.

Note that Powersonic now has a PS-12200NB battery with the same form factor, but with NB terminals and 20 Ah rating at the same weight as the PSH-12180FR. I'd avoid it as it offers no upside.

If you go for a non-powersonic battery, the major motivation would probably be lighter weight to allow a bit better neutral buoyancy and/or ballast to improve the trim.

I also recommend you get a neoprene sleeve for it to protect the joint between the motor housing and the nose cone as damage there is a major source of leaks.

I'd also replace the nose plate with an aluminum or lexan nose plate as the stock plates have a tendency to implode around 130-140' - above the rated depth of the scooter.

 

[yojreilly]

As noted above, the old batteries are two 12V batteries wired in series, so you need 24V for the motor to even notice it's connected to a battery.

There are lots of batteries around in that form factor, but weight and power delivery traits tend to vary, so I tend to stick with Powersonics. I like the Powersonic PSH-12180FR in the larger Mako scooter, but they are 1.2 pounds heavier per set than the PS-12180.

The first is a 21Ah battery while the latter is an 18Ah battery but the major difference is that the former allows for a higher discharge rate, and it's somewhat subjective but I seem to have a bit more power available on continuous scooter runs over about 30 minutes with the PSH-12180FR in my 1000 rpm Mako scooters.

Note that Powersonic now has a PS-12200NB battery with the same form factor, but with NB terminals and 20 Ah rating at the same weight as the PSH-12180FR. I'd avoid it as it offers no upside.

If you go for a non-powersonic battery, the major motivation would probably be lighter weight to allow a bit better neutral buoyancy and/or ballast to improve the trim.



Do

I also recommend you get a neoprene sleeve for it to protect the joint between the motor housing and the nose cone as damage there is a major source of leaks.

I'd also replace the nose plate with an aluminum or lexan nose plate as the stock plates have a tendency to implode around 130-140' - above the rated depth of the scooter.

Thanks for the reply's
I ordered battery's, heavy nose plate, o rings today.
I'm thinking to add a amp meter or three light amp meter like the Mako has in the head light since i'm not using the light.
It would be nice to know when your at half charge left.
Seems it should just work off the lights wires.
Any Idea were I might find a three light amp meter?
Thanks

 

[Peter_C]

If you are putting in a see thru nose plate made of Lexan, then you could just put in a small digital voltage gauge. In fact I might have to do that in my Mako. The LED's are about useless.

 

[jamesb]

A voltmeter gives the best information under load but if you can't see it under load, it is less useful. A bad battery can show full voltage under no load and be dead when you pull the trigger. Also, 25.4-25.6 is fully charged and 24 is dead under no load so you need a meter with good resolution. That is why the LED is useless, their range is too small. As the battery ages things change a bit too. An amp meter alone doesn't give as much information as a voltmeter. Under load expect 24 volts on a fresh sealed lead acid battery and 22 volts is nearly dead. At 21 volts you will be towing it soon.

 

[Peter_C]

The batteries do take a few seconds to recover voltage once off the trigger though. Plus you could always clamp the scooter between your legs and hit the trigger to get a reading.

 

[DA Aquamaster]

Thanks for the reply's
I ordered battery's, heavy nose plate, o rings today.
I'm thinking to add a amp meter or three light amp meter like the Mako has in the head light since i'm not using the light.
It would be nice to know when your at half charge left.
Seems it should just work off the lights wires.
Any Idea were I might find a three light amp meter?
Thanks

All the above comments are valid.

I use an Eagle tree data logger and power panel in the nose under the lexan plate. It shows voltage and you can set the parameters - but more importantly, it also lets you track the miliamps used. If you track the data over time, it tells you a lot about the effects of higher flow, different prop pitch, run times, etc on total miliamps used, maximum amps pulled at any one time, amps currently being drawn and how much you have left in the charge at any given point. It also lets you spot trends and sudden changes in battery health. And on any given dive, it lets you track exactly what you've used to that point, in addition to current battery voltage.

And you can hook it up backwards and then monitor your charge - telling you how much current you've put back in, amps/rate of charge, etc.

It's also basically idiot proof and if it fails it won't cause a power loss to the motor.

 

[Peter_C]

Is this the data logger you are talking about? Eagle Tree –R/C RPV RC Heli Model Aircraft Telemetry data logger GPS logger GPS telemetry MicroPower elogger e-logger RC Model Airplane Telemetry jet ECU telemetry Eagletree MicroPower Wireless Telemetry RC data logger Flight Data Recorder high

Kinda expensive but probably works great. I would prefer to put the money towards a Genisis or a Cuda at this point. Although a simple voltage read out would be cheap enough to consider purchasing. I just checked and they can be had off of ebay for less than $3.00 with a buy it now. Like this one that goes up to 30 volts DC. A little double stick tape and some soldering should set it right up. I don't know what the milli-amp draw is of the digital readout though. Matters to me since I never unplug my batteries. Unlike most scooters I have solid state circuitry with speed control that doesn't draw measurable power. Found the specs listed under an Ebay ad. They do come in red, green, or blue.

Operating voltage: 4.5 ~ 30V
Operating Current: <60mA

 

[DA Aquamaster]

Yes, I use the eLogger V4 and power panel. It's the same one used in the Tahoe Benchmark. Order one with the wire leads, then solder on the required connectors. Even though I have not seen more than a 21 Amp load in my scooter, I case 50 Amp Anderson connectors on all our scooters, chargers and batteries. They don't come unsnapped as can happen with the smaller 30 Amp Anderson format, and they are far better than the trailer connectors used in the stock Tekna and Mako. With long runs (40 minutes) on a 1000 rpm motor, I noted the stock connectors were getting warm, as evidenced by some permanent deformation of the rubber parts of the connectors.

Eagle Tree &#8211;R/C RPV RC Heli Model Aircraft Telemetry data logger GPS logger GPS telemetry MicroPower elogger e-logger RC Model Airplane Telemetry jet ECU telemetry Eagletree MicroPower Wireless Telemetry RC data logger Flight Data Recorder high

The eLoggger is $70 (I use the 100 Amp model), and the power panel is another $30. I also use a 12" extension to allow a bit more room to attach the power panel to the nose plate. I hold it in position with 2 velcro strips behind the power panel.

It's arguably expensive, but it's a lot cheaper than a burn tester and gives you a lot more information on battery performance and health.