Question about HT1000 charger NTN1174A

[Josh380]

First thing I notice about this charger...doesn't appear to stop charging when the battery reaches capacity, and I don't like that. I feel like I'm overcharging and effectively frying my battery. I never have the radio on while in the charger, so it's probably not as bad as it could be, but I want something new.

With that being said, I'm curious if there's a way to modify the charger to either stop charging when the battery reaches capacity, or give me some sort of visual signal that the battery is done charging.

See, I'm kinda cheap, mostly because I don't have a ton of money, so if there's a way to accomplish this without buying a new charger (and making my current one...well..useless), I would love to know how.

BTW, I have a 1200mAh battery, and I have no clue what the typical charge time would be, and honestly, a light or a charge-cutoff would be a lot easier than keeping track of time.

Any ideas?

 

[N4KVE]

That charger is the slow charger from hell, & a total waste of time. It belongs in the trash. At the last 2 ham fests I was at, a seller had buckets of these current tri chem chargers, including the wall wart for $10 each. I suggest you try to find one of these $10 chargers. All the battery chemistries work well on this charger.
Motorola NTN8831B Charger Base | RadioParts.com

 

[teufler]

a ball park figure , for charging time, look at the charger output, mah output, then your battery size, and divide the twop, and you get the time. If your ht 1000 chareger has a small wall wart, , thats called a slow charger. The big wall wart is the rapid charger, about 2 hrs. The small wall wart is 200 mah output so its called the slow or trickle charger. Usually 10 hrs or more is good.

 

[Josh380]

Big wall wart? Small wall wart? The wall wart says 12v 2.4w output. No mAh output. It is a motorola wall wart too. Here's the p/n for the wall wart: 2580955Z02

 

[teufler]

Sounds like you have the large wall wart. wall unit is slightly heavy, I have a bunch here but I think they are in storage downstairs. I found the small one,. The pin that inserts into the desk charger is more robust. So if it says 2.4 watt output, that about 2-3 hours, the battery should be good to go. I can't remember if the charging light changes color on full charge. Youi could plug ther unit into a timer, and set it for 3 hours.

 

[Josh380]

The charge light does not change color or turn off...main point behind my original post. I suppose I could get a timer for it...I just figured there might be some sort of fuse or relay or something I could solder inline that would trip when the battery reaches full charge...sorta like the temp limiters on coffee makers.

Interesting thing I noticed about my charger base...no screws. Just 4 clips to unlatch..odd. I wonder why they opted for clips instead of screws......

 

[N4KVE]

The charging tray [1174] with 2 pins to contact the battery is the slow charger. Only the small wall wart will fit, as the large wall wart has a different plug that won't plug into the 1174. The 2 pins are for charging only. +, & -. When you get the fast charger, there is a 3rd pin [& sometimes 4] which reads battery voltage, & tells the charger to shut off when the battery is full. Since the 1174 only has 2 pins, there is no way for the charger to know that the battery is full, & not paying close attention will cause the battery to overcharge. I recently gave my last 1174 charger to a friend for free, as he lost his only charger.

 

[Josh380]

The charging tray [1174] with 2 pins to contact the battery is the slow charger. Only the small wall wart will fit, as the large wall wart has a different plug that won't plug into the 1174. The 2 pins are for charging only. +, & -. When you get the fast charger, there is a 3rd pin [& sometimes 4] which reads battery voltage, & tells the charger to shut off when the battery is full. Since the 1174 only has 2 pins, there is no way for the charger to know that the battery is full, & not paying close attention will cause the battery to overcharge. I recently gave my last 1174 charger to a friend for free, as he lost his only charger.

Finally...an answer I'll buy for a dollar (not really, but you know what I mean). I figured I had the slow charger, since a search on ebay for the rapid charger turns up one that looks completely different.

So I guess there's no way around it. Gotta plunk down $20 for the rapid charger, since I don't like having to wait forever for a full charge. Geez..all the accessories for this radio are expensive. I'm spending more on the accessories than the radio cost.

I've been charging the radio for about 6 hours, so if teufler's ball-park figure is accurate (10 hrs), then I haven't overcharged the battery.

 

[cmdrwill]

The NTN1174A is a slow rate charger. It does not 'shut off'. Depending on the battery, the time is 16 hours.
Intended as a 'overnight charger' for the standard battery. Some call it a 'trickle charger'.

"The wall wart says 12v 2.4w output." puts out about 25 miliamps. That is all the slow charger needs, it steps that down to 7.5 - 8 volts at constant charge current of 20 miliamps.

" no screws", the clip together was much faster to build.

The "fast charger" can over charge your battery if left in the charger for more than one hour after the charger goes green, Complete.
There is a mod that will change the "Complete" charge current to a lower value.

 

[Josh380]

There is a mod that will change the "Complete" charge current to a lower value.

Got a link to that mod?

 

[slicerwizard]

The NTN1174A is a slow rate charger. It does not 'shut off'. Depending on the battery, the time is 16 hours.
Intended as a 'overnight charger' for the standard battery. Some call it a 'trickle charger'.

"The wall wart says 12v 2.4w output." puts out about 25 miliamps. That is all the slow charger needs, it steps that down to 7.5 - 8 volts at constant charge current of 20 miliamps.

Math fail.

And no way will 25 mA fully charge a > 1Ah battery in 16 hours. This should be obvious...