Battery pack modifications?

[robertk]

One of the FAQ's on Whites website asks if you can use the spare alkaline battery case to make your own NiMH rechargeable battery pack. The answer says to "see the forums" for people who have done just that. I don't know which forums they refer to (didn't see a link?), but I can't find any such info. Does anyone know what's involved? It's not just a matter of putting NiMH batteries in the alkaline battery pack, because the alkaline pack doesn't have the center port for charging. Is there a simple way to add the charging port, or is this a really dumb idea?

 

[Saldog1]

Are we talking OVER KILL ? The rechargeable battery pack and the spare battery pack with alkaline batteries will give you ?????? 12 15 18 hours ?????
Why not just get rechargeable AA's with their own recharger, instead of trying to modify the spare battery pack..anyway you look at it, you're gonna have to be close to an electrical outlet.

 

[Rob (IL)]

I can send you a link to the post that shows the pictures of the mod. I can't post a link to another forum on Finds. It's pretty simple. It just saves you the time of taking the batteries out of the pack. As was stated if you take the batteries out and use a separate charger you don't have to do the mod to the pack. Rob

Parts

8 AA rechargeable batteries
Coaxial power jack Radio shack part # 274-1582
Diode 1N4001 Radio shack part # 276-1101
Two inches of hookup wire ( any insulated wire)

TOOLS

Drill

 

[robertk]

Ah. Is it OK to PM the link to me? I realize it only saves removing the batteries to charge them, but it also saves buying a separate charger and having it plugged in. I already have a half-dozen chargers plugged in and sitting on the counter. I'm not committed to the idea yet, I just want to see how difficult it is...

 

[Willee - Texas]

I own a BeachHunter ID and it uses a rechargable battery (green label) similar to the one in the V3. (red label)
It would have been nice to use the White's desk charger that came with the V3 to charge them both but they are slightly different and wont fit into the charger properly.
However, the V3 pack (red label) will work in the BHID so buying a second V3 pack is an option.

I understand about having many different chargers laying about ... most of which are unmarked as to what detector they go with.
Placing a white address sticker with information about what battery it charges on the wall wart helps a lot.

 

[Larry (IL)]

The batteries for each detector are different and require their own chargers. The V3 uses Lithium Ion batteries. The battery packs can be used with different machines once charged in their own chargers though.

 

[jgedde]

Larry is right about the charger compatibility, however the V3 uses Nickel Metal Hydride batteries (NiMH) not lithium ion. Lithium ion chargers and battery packs use smart charging technology to prevent damage to the pack/charger or the operator and they incude a monitor IC in the pack. The V3 pack has none of this inside and the cells are marked NiMH. Lithium Ion batteries are very dangerous if misused. My company is working on new products to allow the safe use of lithium ion technology with cell balancing in space vehicles.

That said, the battery pack mod on the other forum is for NiCAD batteries and may or may not be compatible with the V3 charger. I've opened up my V3 rechargable pack and intend to reverse engineer what's in the pack/charger tomorrow (which I won't share without permission). I'll modify an alkaline battery pack to use NiMH AA cells. Stand by. I will post instructions for modification of the pack. I'm not anticipating any headaches.

John

 

[Larry (IL)]

I stand corrected....You are so right. It is the TDI that uses the LI-ION system.

 

[jgedde]

I've opened up my V3 rechargable pack and intend to reverse engineer what's in the pack/charger tomorrow (which I won't share without permission). I'll modify an alkaline battery pack to use NiMH AA cells. Stand by. I will post instructions for modification of the pack. I'm not anticipating any headaches.
John

I've successfully reverse engineered the pack and charger. I'm now building a high capacity (2500 mAH) battery pack for the V3 based on the alkaline pack. This pack will provide more run-time than OEM NiMH pack (1600 mAH???). I had to order parts to modify the alkaline pack into a NiMH pack. Here's the bill of materials for the modified pack.

8 Energizer 2500 mAH AA NiMH rechargable cells (search online for an 8-pack - should be about $22)
1 10k NTC glass body thermistor (Beta=3890K). Digikey 615-1016-ND (80 cents each)
22 gauge stranded wire
1 new clad dime (used as the third battery pack contact. I didn't have a small piece of nickel or gold plated sheet metal and it's important to use a contact material that doesn't readily oxidize like steel, aluminum, brass, copper, etc)

Also needed: solder, soldering iron, tin snips, epoxy adhesive (I used JB Weld), hand drill, 9/32 drill bit.

When I get the parts, I will post photos of the process and document. It's fairly simple.

(The White's charger uses a thermistor (temperature sensing resistor) inside the battery pack to monitor the charging. When the pack reaches a certain temperature, the charger turns off because no more energy can be used to charge the cells, and they start to warm up. Taking advantage of this effect allows the charger to know when the pack is fully charged.

The beta of the thermistor I chose is slightly higher than the beta of the thermistor in White's pack. The Energizer cells aren't as tolerant to high temperatures during charging as the cells used in the White's pack, so using the higher beta thermistor won't allow the cells to get quite as hot (difference of about 5 degrees C) before the charger shuts off.)

 

[Larry (IL)]

Here is another way of doing it. I did this for my DFX and it works just as well for the V3. Nancy found on Ebay, two packs of 4 Energizer 2500 mAH AA NiMH rechargeable cells with their own chargers. I think we paid about $10 each with a little bit of freight for the two packs. I'm sure it was less than $25. I charge the cells in their own chargers and put them into an alkaline battery holder, so instead of alkaline batteries, I now have a NiMH pack in reserve for my backup pack.

 

[duclaw]

Larry, you beat me to the punch! I do the same thing for my XLT and get 10+ hours out of them from 1 charge. Seems a lot easier(and safe) to do and fairly cheap, especially in the long run.

 

[robertk]

I've successfully reverse engineered the pack and charger. ...
When I get the parts, I will post photos of the process and document. It's fairly simple.

That sounds great -- I'm looking forward to seeing the process. Sounds like aside from the batteries themselves, it's only about a dollar in parts. I already bought a set of those batteries, so being able to charge them in the case in the stock charger would be great!

 

[captainron]

I started using NiMH rechargeables from the get-go for the spare battery pack, even when I owned the DFX beforehand. No other way.....in my opinion.

 

[teckpro]

I Have filled the alkaline packs with NiMh and I used a Sensing charger to charge 2 packs at the same time. I also Made a "drop in" battery holder out of wood, with contacts.

However I allready had the sensing charger.
Since the company went this route , Jgedde's plan works fine for the lowest cost.