Pulsar DNV battery packs refuse to charge.

[Nugs]

A plea to the more technically minded.....

Twin Pulsar DNV battery packs purchased about 18 months ago now refuse to charge.
Thermal is a HD50s. DNV batteries certainly haven't been charged more than about 100 times each, so should be within their life expectancy.
The charger light goes green from plugging in (should be red to denote charging cycle), even though the battery indicator on the HD50s states low capacity.

Any suggestions, as it doesn't appear i can buy the charger separate, and i refuse to shell out another 70 notes for a £10 charger.

 

[Tim.243]

If it has a usb lead, try it in the car through the cig lighter port

Tim.243

 

[Nugs]

If it has a usb lead, try it in the car through the cig lighter port

Tim.243

No USB Tim, batteries can't be charged whilst in the unit, and have to be charged in the dedicated 3 pin plug charging station.

 

[finnbear270]

Charging station available from a friend?, test charge on theirs?

 

[sikasako]

Haven't had any charging issues with My DNV batteries, which are older than yours and have a fair bit of use.

As mentioned above, if possible try borrowing another charger to see if it's at fault.

If you still have your AA battery unit, try it (with healthy batteries) in your HD50s to see what battery indication it gives.

If you do manage to borrow a Dnv charger, then it would also be worth borrowing a healthy battery pack to try in your charger and HD50s.

 

[Tim.243]

No USB Tim, batteries can't be charged whilst in the unit, and have to be charged in the dedicated 3 pin plug charging station.

oh pants my xq38 as a 3 pin plug with a usb outlet and fly lead

Tim.243

 

[Nugs]

Charging station available from a friend?, test charge on theirs?

Haven't had any charging issues with My DNV batteries, which are older than yours and have a fair bit of use.

As mentioned above, if possible try borrowing another charger to see if it's at fault.

If you still have your AA battery unit, try it (with healthy batteries) in your HD50s to see what battery indication it gives.

If you do manage to borrow a Dnv charger, then it would also be worth borrowing a healthy battery pack to try in your charger and HD50s.

Thanks all, i need to eliminate the charger first....... looks like i will be putting out a plea to the SD massive.
I do still have the battery cradle, will pick up some new batts to try.

 

[pinkfoot1]

If they are NiCad and go flat the charger is unable to begin a charge as it is unable to detect voltage in the battery. If you have, or can borrow any sort of battery with about double the voltage of your faulty battery you may find if you connect negatives together and then briefly, as in a quick tap, positive to positive about six times you may introduce enough voltage to enable the charger to deliver.

 

[pinkfoot1]

BTW, this works for any NiCad that seems dud. The problem is the supposedly intelligent chargers which lack the intelligence to spot when cells needs a kick-start.

 

[Andy-shooter]

Looking at the spec the DNV uses Ni-MH cells (not NiCad).

Cell voltage will be 1.5v when absolutely full, about 1.2v for most of the majority of the charge and then 1.0v when flat. The DNV uses 4 cells in series.

If the voltage you measure at the output of the pack is significantly less than 3.6v there is every chance one of the cells has gone open circuit which is fairly fatal to the pack. If it is between 3.6 and 6v the pack is likely to be fine and the charger could be suspect.

Andy

 

[Andy-shooter]

I should add that Ni-MH charging is somewhat complex, normally the charge is terminated by the rate of change of temperature increasing. (Signifying the cell can’t absorb any more energy and the charge current just turns to heat).

If you don’t use the right charger there is a very good chance the cells could be damaged.

That said, pinkfoot’s trick of pulsing small amounts of charge into a pack which has got below 1.0v per cell ( 4v for the DNV) can get the cell voltage up to a level where the charger can start to work. For the DNV I would try boosting using an applied voltage of about 5v.

 

[Nugs]

Cheers Andy and Pinkfoot, one of the batts is at 3.8v and the other at 5.4v. The charger still refuses to charge the higher so i suspect the charger may be at fault....... now to try and source a new one.