JJ CCR both shearwater and hud dead

[Madddogggy]

For those not on the bookFace. Here is a link to a Shearwater post to discussing a possible issue with the Shaft batteries.

Under Performing SAFT Batteries - Shearwater Research

 

[Madddogggy]

I believe so... I think if we put some resistance on it that we might see a much lower voltage. Not sure though how to do that... I have a multimeter... but not much else.

Do you have any lights/toys/gadgets that operate off a single AA battery? If so, let me know and I can walk you through checking the batteries if you still care.

No I didn't not stay in a Holiday Inn Express, but I am a practicing EE.

 

[beester]

Do you have any lights/toys/gadgets that operate off a single AA battery? If so, let me know and I can walk you through checking the batteries if you still care.

No I didn't not stay in a Holiday Inn Express, but I am a practicing EE.

Yes I do (I have a 2,5 year old son so plenty of toys lying around :-D) , if you don't mind taking the effort!

Thanks

 

[Madddogggy]

Yes I do (I have a 2,5 year old son so plenty of toys lying around :-D) , if you don't mind taking the effort!

Thanks

No problem. I'll write it up for you during my lunch break. Depending on the pencils you have around your house it may work as a load as well, but you will need to check the resistance of the pencil lead first with your multi-meter before applying a voltage across it.

 

[beester]

No problem. I'll write it up for you during my lunch break. Depending on the pencils you have around your house it may work as a load as well, but you will need to check the resistance of the pencil lead first with your multi-meter before applying a voltage across it.

To make sure I don't fry the multimeter or put too much stress on the battery?

 

[Gone for diving]

Quick and dirty way with small batteries is.. check the voltage should be 1.5v-1.25 ish is spec... then put amp meter on 10amps. And touch the leads... for about as long as it takes to read the amperage aprox 1.5 seconds.
(5amps and up is a quite good battery...
Lower not as good. But even 1-2 amps is still good for low draws)
Test a new battery and it gives a good starting point...
Occasionally you will have a good voltage battery but can't put out any current... those are the ones that get you in trouble.

That's how I sort similar batteries when I have a mishmash of batteries and know one knows the state of use...

 

[Madddogggy]

To make sure I don't fry the multimeter or put too much stress on the battery?

Depending on the on what's being measured and how it is being measured, one or both could fail or greatly shorten its useful life. Fortunately, multi-meters have fuse protection in the event of excess current draw. But fuses are similar to incandescent light bulbs, small amounts of metal, flake off with time and they will eventually blow, specially when the current is repeatedly near the rated max.

 

[Madddogggy]

To make sure I don't fry the multimeter or put too much stress on the battery?

First: Here is the Voltage vs Current Load graph for the Saft LS14500 (AA). The voltage measured will depend on the load, so if possible keep the load to greater than 72 ohms or less than 50mA for a long duration. Lower resistances/higher currents can be used for short lengths of time, but Saft recommends the max pulse current draw be 250mA for 0.1seconds.

Equipment:
1) Multi-meter + probe leads: set to measure Volts - DC.
2) Graphite pencil lead than has an adequate resistance, and/or electronic device that operates off a single li-ion battery (ex. 18650) that the power/ground pins are reachable/available to make contact with. (Use the ohm-meter function of the multi-meter to measure the resistance).
3) Power and ground wires to connect from the battery's (+) and (-) terminals to the load (resistor, pencil lead, electronic device
s (+) and (-) respective terminals). The resistor and pencil lead do not care about which each is (+) or (-), but the electronic device does.
The wires should be long enough to connect from the load to the battery and be insulated except at the ends that connect to the load and battery.
4) Rubber-Band, zip-tie, second set of hands,etc: used to hold power and ground wires to the battery terminals.

Steps:
1) Determine what the load is going to be and verify it was stress the battery to much. This test is short, a few seconds so going over the 50mA max continuous current shouldn't damage the better or reduce its useful life to much. Equation (Ohm's Law) : Volts(DC) = Current (Amps) * Resistance (Ohms).
2) Connect the power and ground wires to the load before connecting them to the battery terminals. Depending on what wires/probes came with the multi-meter, they may be better options that ordinary wire. FYI, this is very low current and short duration, the wire gauge size is not critical.
3) Set up the multi-meter and probes (assuming this is known) and select Volts-DC to measure.
4) Connect the opposite end of the wires to the appropriate battery terminal. For electronic devices (+) to (+) and (-) to (-).
5) Use second/third set of hands/rubber-band/zip-tie to hold wires in place to battery.
6) If using an electronic device, turn it on and verify its working.
7) Measure voltage across battery terminals.

Results:
1) Depending on the load size (Resistance/Current Draw) verify that voltage is within specification in chart in this post. If the load is greater, ie higher current draw than the voltage may be lower.

Disclaimer: I didn't review the posts for grammar.

If you have any questions, don't hesitate to ask.

Sincerely,
Matt

 

[beester]

I sourced the resistors (luckily have an electrical store very nearby) and tried putting the 2 suspect SAFT batteries on. The result was amazing (or very strange if you will). With no resistance they both showed 3.5 volts, but putting on the resistor they were totally dead, not showing any voltage.

 

[Gone for diving]

That will do it!!!!
It possibly has a connection problem inside, (most probable)
Or for some strange reason it's going to 3.5v after dead....