Mar 222014
La Crosse Technology BC-700 Alpha Power Battery Charger
- Battery charger for NiCad and NiMH AA and AAA rechargeable batteries
- Features 4 modes: charge, discharge, refresh, and test
- Charges both AA & AAA rechargeable batteries simultaneously
- 4 separate LCD displays for simultaneous readouts
- Overheat-detection to prevent over-charging
The La Crosse Technology BC700 Alpha Power Battery Charger has four modes and charges all NiCd and NiMH AA and AAA rechargeable batteries. The four modes include charge, discharge (discharges the batteries and then recharges them), recharge (discharges and recharges up to 20 times to bring old batteries back to life) and test (displays the battery capacity). BC-700 Battery Charger ” Features: • All modes automatically default to 200 mA charge on the BC-700 Battery charger • Charge both AA
List Price: $ 49.95
Price: $ 28.77
BC-700/900/1000 FAQ,
[Update on April 4, 2012]
My original review was written back in August 2007. Now, nearly 5 years later, most of its content is no longer current. So I will use this spot for publishing my “Frequently Asked Questions” relating to BC-700/900/1000 family of chargers. This list is work in progress and will grow with time. Let me know if you have new questions to be added. Here goes…
[Q1] There are four operation modes on the BC-700 (Charge, Discharge, Test and Refresh). Which mode should I use and when?
[A] Most of the time you just need CHARGE mode. That means put in the batteries and select the charging current desired (500/700mA, etc)
- If you want to know how much capacity your batteries can actually hold, use the CHARGE/TEST function. Be careful not to run this operation if the batteries are freshly charged (doing so may lead to over-charging).
- If you want to find out the remaining charge in a battery, run DISCHARGE/REFRESH and record the ‘mAh’ number at the end of the first discharge.
- If you suspect your batteries suffer from reduced capacity, run the DISCHARGE/REFRESH operation. Or you can use this mode to refresh your batteries once every 6 months or so. Don’t over do it!
[Q2] Why won’t the MODE button response when I press it?
[A] Press and hold the MODE button for 3 seconds, then toggle it to change mode.
[Q3] What is the difference between TEST and REFRESH?
[A] TEST starts with a full recharge, then it discharges the cell once to determine its capacity. Next it recharges the cell to full again.
REFRESH starts with a discharge to determine the cell’s remaining charge capacity, then it charges the cells back up and drain it down again to determine its new capacity. It wil repeat this Charge/Discharge cycle multiple times until the capacity stops improving. Finally it charges the cell in the end.
[Q4] My BC-700 has been discharging and refreshing for 3 days!! When does it stop?
[A] The REFRESH operation takes at least three Discharge/Recharge cycles to complete. If you use the default 100mA discharging (200mA charging) current for a 2000mAh AA cell, each Discharge/Recharge cycle takes about 30 hours! Terminate the Refresh operation and restart it using 350mA discharging (700mA charging) instead.
[Q5] What is the best charging current for recharging AA or AAA batteries?
[A] For AAA cells the default 200mA is just right. If you’re in a hurry, increase the current to 500mA.
For AA cells you should increase the charging current to either 500mA or 700mA. This reduces the charge time and, more importantly, ensure that the charger will not miss charge termination signal and ends up over-charging your cells.
[Q6] How does the BC-700 know when to stop charging?
[A] The primary termination mechanism is “negative delta-voltage detection” (-dV/dt). If this signal is missed, backup mechanism include: high voltage termination, over-temperature shutdown, and safety timer (stops when total charge > 3700mAh)
[Q7] I ran a Charge/Test operation but in the end it shows a capacity reading of “000 mAh”. Are my batteries dead?
[A] Most likely the charger missed the -dV/dt termination signal, and subsequently tripped either over-voltage or over-temperature shutdown.
[Q8] I used the BC-700 to recharge my Duracell 2650mAh batteries, and the capacity readings are over 3000mAh. Are those batteries great or my charger is bad?
[A] When you use CHARGE, the ‘mAh’ reading is for amount of charge going INTO the battery, not what is actually STORED by the batteries. Because the energy conversion is not 100%, you always need to put in more charge, especially if your batteries are old or leaky. To find out the charge stored, use either Charge/Test, or Discharge/Refresh
[Q9] I put in a set of exhausted batteries and one of them shows ‘null’. Is the battery dead?
[A] If a battery has been over-discharged, its terminal voltage may fall below 0.5V and the BC-700 cannot detect it. You can kick-start it by using my “Paper Clip trick” (see customer image section for details), or by charging the dead cell in a dumb charger for a few minutes. Then the BC-700 will recognize it.
[Q10] Why can’t I tell how much charge is left in my battery instantly?
[A] No battery testers in this world can do that. The only reliable way is to run Discharge/Refresh. However, you can estimate the `fullness’ of your battery by looking at its voltage. When you first insert in a battery, its voltage is displayed for 8 seconds. If the voltage is higher than 1.30V, the battery is mostly full and you don’t need to recharge it. If it is below 1.20V, it is nearly exhausted.
[Q11] How do I power the BC-700/1000 from my car battery?
[A] You need a CLA (cigarette lighter adapter) with 3V output at a 2.1/5.0mm barrel jack; current rating of 3A for the BC-700, 4A for the…
Read more
Was this review helpful to you?
|Best charger I ever owned,
UPDATE: (08-12-2012) It has been 5 years since I wrote this review. This charger is still working great!
I have owned at least 8 chargers in the past, Maha’s, Panasonic, etc. It is nice to see that this charger shows you the mAh on the LCD panel as the battery charges up. Most chargers you only see an LED indicator to signal when charging is done.
Compared to the specs of BC-900, the BC700 can only go up to 700mA (the max) which means it is somewhat slower than the BC900. But the faster the battery charges, the hotter it gets. And one of the worst enemy of rechargeable batteries is heat. Less heat means longer life for the batteries.
Pros:
- 3 adjustable charging speeds
- Will show you the actual capacity in mAh. This is good so you know which battery needs to be refreshed. You always want to use batteries with the same capacities in pair or in a group.
- 4 independent charging stations with individual LED readouts. “AA’s” and “AAA’s” can be charged in different combinations. Don’t you hate those gadgets that only use 3 batteries like portable radios? (walkie-talkies). You end up with 1 un-used battery if you bought a 4-pack. How will you charge it if your charger only charges in pairs?
- Reasonable price for an excellent charger
- Small and light. Better portability
- Multi-volt up to 240v. Very useful if you travel a lot to other countries.
Cons:
Now I have to stop myself doing impulse buying on NiMh’s because I enjoy using this charger too much.
Was this review helpful to you?
|Great charger but…….,
This is a great charger and when I bought it it was about $15 less than the BC-900. Now the BC-900 is less than this charger. The difference between this charger and the BC-900 is the lack of the faster charging speeds and the accessories. Definitley buy the BC-900 and the accessory package for less money. It seems they are constantly playing games with the pricing on these two chargers. The BC-700 charger does a great job of reconditioning batteries and the charging speed is usually between 2-3 hours for the different capacity batteries that I have. (1800mh – 2650mh). Time is not an issue for me as I have about 10 sets of AA’s and can just keep swapping them out. From what i’ve read the slower charging speed is better for the life span of your battery any way.
Was this review helpful to you?
|