I have a Snap-on 18V cordless impact that's about 6-7 years old. Anyhow, over the last 6 months or so it seems that both of my battery packs won't hold a charge very long, go dead within a day or two of non-use, and don't have much power even when left on the charger overnight.
I know some batteries there are processes to restore "full power" to them so to say.
Anyone know if this is the case for a Snap-On battery packs? IN particular, this is a CTB3185.
Otherwise, I guess I'll hit up that ebay store that rebuild them for like 50 bucks...
I was told never to leave them on the charger, and that they have an average life expectancy of @2 years. FWIW.
If they are Ni-cads they are gone. You can probably find someone to rebuild them.
I have a similar situation. I have not tried this myself, but I do know folks that swear it has worked.
So undertake this at your own risk.
"according to the internet" ..... (Google and you will find)
You can restore much of the capacity. It involves a 'brief' reverse charge from a greater voltage source. Two 12V car batteries in series will make a 24V that should do the trick. Attach heavy leads to the pack contacts (minding the polarity), and connect one of the leads to the 24V battery.
The other lead is briefly touched to the other 24V battery terminal a few times (8-10? with attendant sparks of course) longer duration connections are discouraged due to the possibility of Ni-Cd cell explosion.
Recharge the pack, and then test. If it works, cool, but some of the cells (15 I think in an 18V pack) may not revive, and you can cut out and replace them with good ones.
The explanation given is that repeated cycling builds up crystaline structures in the electrolyte that act as internal short circuits. The brief reverse high current spikes break up these structures, allowing the cells to work properly.
Carter
erohslc wrote:
I have a similar situation. I have not tried this myself, but I do know folks that swear it has worked.
So undertake this at your own risk.
"according to the internet" ..... (Google and you will find)
You can restore much of the capacity. It involves a 'brief' reverse charge from a greater voltage source. Two 12V car batteries in series will make a 24V that should do the trick. Attach heavy leads to the pack contacts (minding the polarity), and connect one of the leads to the 24V battery.
The other lead is briefly touched to the other 24V battery terminal a few times (8-10? with attendant sparks of course) longer duration connections are discouraged due to the possibility of Ni-Cd cell explosion.
Recharge the pack, and then test. If it works, cools, but some of the cells (15 I think in an 18V pack) may not revive, and you can cut out and replace them with good ones.
The explanation given is that repeated cycling builds up crystaline structures in the electrolyte that act as internal short circuits. The brief reverse high current spikes break up these structures, allowing the cells to work properly.
Carter
yeah, been doing some reading since I posted this question and looks like they're toast. I got 5-6years out of them, so that's not bad. Definitely not planning to go to any majore effort like that, lol.
Also these are 18V, so I'd need 1 1/2 car batteries to even try that haha.
There's a place on ebay that for $45 will rebuild them, so I think I'll go that route!
I thought about trying one of those Battery Warehouses in our area to see if they rebuild or just stock the ones I need. My $80 impact can get 2 wheels off after 4 years and being stored in my garage (cold PA winters).
I have an older Snap-on model, so they don't sell the batteries anymore. But I don't want to get something new, since this thing has great gearing and blasts big-time bolts off (try rusty old lag bolts on a deck, or major suspension bolts on a 40-year-old rusty-as-hell car)....Lugnuts come off with a very short burst, easily.
Guess I'll send the batteries to the ebay rebuilder and see how they do. They offer 2100ah and 3300ah service on this battery (original one is 2300ah) for $45 or $75 respectively. Not a bad deal to not need to buy a new $500 impact :D
From what I understand you can rebuild them yourself fairly easy. Pull the battery appart, make note of how the cells are arranged and then go to an RC store and get a like number of cells.
The local Battery Warehouse store will rebuild them for not much more then you can buy the individual cells yourself. I've done that on a pack that wasn't made anymore. I have another in a pentop that I think I'll let them do.
Just as a side note, with the $20 18V drills from HF, for example, they give you a dumb charger. That is, it has no type of overcharge prevention. There's a little note that says don't leave it on the charger more than 6 or 8 hours or something. What I did is buy a light bar, outlet box and a spring timer. I wired it all up so that I plug all the HF dumb chargers into the light bar, put a battery in whatever charger it fits, turn the timer on to 6 hours and leave it. It turns off after 6 hours and won't cook the battery.
Most nicads go bad over time when the water in them gets blown off.
In reply to irish44j:
I've found that Interstate sells replacement batteries for just about everything. Might not be as cheap as rebuilding, but they seem to be reasonably priced.
irish44j wrote:
I have an older Snap-on model, so they don't sell the batteries anymore. But I don't want to get something new, since this thing has great gearing and blasts big-time bolts off (try rusty old lag bolts on a deck, or major suspension bolts on a 40-year-old rusty-as-hell car)....Lugnuts come off with a very short burst, easily.
Guess I'll send the batteries to the ebay rebuilder and see how they do. They offer 2100ah and 3300ah service on this battery (original one is 2300ah) for $45 or $75 respectively. Not a bad deal to not need to buy a new $500 impact :D
My local snappy dealer is priced at $300 for the impact kit and 2 batteries. Not bad for the usual price of snap on.
