BrianMc
Enlightened
- Joined
- Nov 4, 2009
- Messages
- 940
I went to BatteryUniversity.com, read threads here and on MTBR and I have a result that makes little sense to me.
Suspect: A nominal 12 volt 4.5 Ahr or 54 Whr (new) NiMH battery with protective circuitry, On/Off switch, on LED and low level warning LED. NOS (a year or more on shelf?) after 19 months of use (daytime running light, too), it would run a 14 watt HID 3.3 hours last September and a nominal 3 watt MR16 LED 12 volt bulb over 11.5 hours off a fast charge to 13.8 volt or so, or circa 46 Whr when checked in November.
Fresh off a fast charge voltage is 13.8-13.9 V range. Fresh off a night long trickle charge, 14.2-14.3 V. Both chargers specifically made for this battery.
I did a number of shallow use/recharges using it while testing lights & riding over the last two months. It was unused for a month before that.
First 'full' recharge with fast charger (charger green LED indicator on) I did beamshots for about an hour with two lamps between 0.5 and 1 A each, usually both at 1 A, then wore the helmet to help the clean up running at 1 A. Battery low LED came on, so dropped to 0.5 A and OK until done. Total run time less than 2 hours, 40-50 minutes with two lights at 1 A. Capacity at an average 15 watts was 30 Whr, maybe less.
A second fast charge and a day run with both lights on, one at 5.5 watts the other at 10 Watts, also gave about 2 hours, so also about 30 Whr.
It had not been trickle charged for 'memory' (NiMH is less susceptible than NiCd but apparently a long time on the shelf uncharged may create an issue, as it did this after the first few charges I used, too).
So I charged it for 19 hours on trickle charge. Battery voltage 14.2 off the charger and test with three XP-Gs driven by a Bflex at 0.75 A. Ran the light for 2 hours and resumed four hours later, for another 5 hours and the red LED battery low light or the set trigger for the 10 volt minimum triple flash set in the Bflex were still not on! Test terminated.
The Bflex needs 1.1 V over the 9.6 Vf of the three LED's. So I assume the load is 1.1 + 9.6 = 10.7 volts at 0.75 A is 8.03 W. The voltage will drop with heat but at 0.75 A, the light was barely noticeably warm, so no more than 85 F (27 C) at room temp ambient, and temp effect is well within Vf error of the LEDs Over 56 Whr and STILL going? TGTBT?
I am going to repeat with two lights confirmed absolutely to be at full power (22 watts total) and under the ceiling fan for air flow and check run time and capacity after a trickle charge to 14.2+ volts off the charger. A repeat would be a runtime of over 2.5 hours. Should be less, as the higher current draw will reduce recovery and total capacity.
OK, I can buy some rejuvenation in a deep discharge and trickle recharge. There's an 11% gain from the 13.8 to 14.2 charge levels, so a return to 40-46 Whr was expected, maybe 50 with the overcharge, but capacity above what it is supposed to do new? It will be in use two years in August and at least a year of shelf time before that. Is this the good side of YMMV?
Comments?
Suspect: A nominal 12 volt 4.5 Ahr or 54 Whr (new) NiMH battery with protective circuitry, On/Off switch, on LED and low level warning LED. NOS (a year or more on shelf?) after 19 months of use (daytime running light, too), it would run a 14 watt HID 3.3 hours last September and a nominal 3 watt MR16 LED 12 volt bulb over 11.5 hours off a fast charge to 13.8 volt or so, or circa 46 Whr when checked in November.
Fresh off a fast charge voltage is 13.8-13.9 V range. Fresh off a night long trickle charge, 14.2-14.3 V. Both chargers specifically made for this battery.
I did a number of shallow use/recharges using it while testing lights & riding over the last two months. It was unused for a month before that.
First 'full' recharge with fast charger (charger green LED indicator on) I did beamshots for about an hour with two lamps between 0.5 and 1 A each, usually both at 1 A, then wore the helmet to help the clean up running at 1 A. Battery low LED came on, so dropped to 0.5 A and OK until done. Total run time less than 2 hours, 40-50 minutes with two lights at 1 A. Capacity at an average 15 watts was 30 Whr, maybe less.
A second fast charge and a day run with both lights on, one at 5.5 watts the other at 10 Watts, also gave about 2 hours, so also about 30 Whr.
It had not been trickle charged for 'memory' (NiMH is less susceptible than NiCd but apparently a long time on the shelf uncharged may create an issue, as it did this after the first few charges I used, too).
So I charged it for 19 hours on trickle charge. Battery voltage 14.2 off the charger and test with three XP-Gs driven by a Bflex at 0.75 A. Ran the light for 2 hours and resumed four hours later, for another 5 hours and the red LED battery low light or the set trigger for the 10 volt minimum triple flash set in the Bflex were still not on! Test terminated.
The Bflex needs 1.1 V over the 9.6 Vf of the three LED's. So I assume the load is 1.1 + 9.6 = 10.7 volts at 0.75 A is 8.03 W. The voltage will drop with heat but at 0.75 A, the light was barely noticeably warm, so no more than 85 F (27 C) at room temp ambient, and temp effect is well within Vf error of the LEDs Over 56 Whr and STILL going? TGTBT?
I am going to repeat with two lights confirmed absolutely to be at full power (22 watts total) and under the ceiling fan for air flow and check run time and capacity after a trickle charge to 14.2+ volts off the charger. A repeat would be a runtime of over 2.5 hours. Should be less, as the higher current draw will reduce recovery and total capacity.
OK, I can buy some rejuvenation in a deep discharge and trickle recharge. There's an 11% gain from the 13.8 to 14.2 charge levels, so a return to 40-46 Whr was expected, maybe 50 with the overcharge, but capacity above what it is supposed to do new? It will be in use two years in August and at least a year of shelf time before that. Is this the good side of YMMV?
Comments?
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