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Nautilus · 01-31-2017, 05:42 AM

Until now, the AGM+supercaps combo performed reasonably.

Reliability: survived -11 to -16ºC (3-12ºF) nights without discharging or freezing. Cranked at -6 to -9ºC (16-21ºF) and above. Supercaps still leak over time, but the combo can hold 12.0-12.3 volts and crank. Connecting the solar panels (which include a pair or small 2.4Ah AGMs) when weather is bright compensates for the leakage, allows it to hold 12.6-12.7 volts over time and 13.0 volts under the winter sun.

Problems: cranked too slowly at -12ºC and couldn't start engine without a jump from a pocket lithium jump starter. Next weekend, after starting flawlessly from cold and running for some time, cranked slowly once in a gas station, when warmed up, for no apparent reason. Saved again by the pocket jump starter. Afterwards it ran properly.

For some weird reasons, the more exercise (start-run-stop-start again warm) is given to the supercaps, the better they perform. If the car is daily driven, they couldn't be happier.

Added a small cooling duct: 3/4" wire-wound rubber duct, from battery box to air filter box, and another from cold air intake tube to battery box. This way, engine draws cool air through battery box. Compared to yesterday (1-5ºC outside temps), today (6-7ºC outside temps) the inside of the battery box (after a similar run of some tens of miles) can be felt much colder.

Total weight moved from front to rear, toolboxes included, is around 42 kg / 92 lbs. Best roadholding is when gas tank (placed amidships, well inside the wheelbase) is half full, not full to the brim. This is not due to fuel weight itself, but to fuel sloshing left-right in tight turns; when tank is full, it can be felt and it's annoying. With half tank it's not.

Side note: all front wheel driven GTI cars are flawed from using small family car chassis and bodywork. Which had been designed for best weight balance when fully loaded. This is the reason for all efforts to balance the weight distribution.

Judging by cost, labor, reliability problems, a hybrid battery with supercaps is more or less a gimmick. Its only visible advantage is light weight. Even giant 2000-3000F caps are not great in this matter, since they approach in weight a small lead-acid battery anyway.

For people who seek a reliable car and they're not too much interested in brisk handling, the 150+ year old lead-acid is far more profitable.

01-31-2017, 05:42 AM	#78 (permalink)
Nautilus EcoModding Lurker Join Date: Dec 2016 Location: Romania Posts: 45 Simba - '05 Seat Leon FR Thanks: 22 Thanked 29 Times in 17 Posts	Until now, the AGM+supercaps combo performed reasonably. Reliability: survived -11 to -16ºC (3-12ºF) nights without discharging or freezing. Cranked at -6 to -9ºC (16-21ºF) and above. Supercaps still leak over time, but the combo can hold 12.0-12.3 volts and crank. Connecting the solar panels (which include a pair or small 2.4Ah AGMs) when weather is bright compensates for the leakage, allows it to hold 12.6-12.7 volts over time and 13.0 volts under the winter sun. Problems: cranked too slowly at -12ºC and couldn't start engine without a jump from a pocket lithium jump starter. Next weekend, after starting flawlessly from cold and running for some time, cranked slowly once in a gas station, when warmed up, for no apparent reason. Saved again by the pocket jump starter. Afterwards it ran properly. For some weird reasons, the more exercise (start-run-stop-start again warm) is given to the supercaps, the better they perform. If the car is daily driven, they couldn't be happier. Added a small cooling duct: 3/4" wire-wound rubber duct, from battery box to air filter box, and another from cold air intake tube to battery box. This way, engine draws cool air through battery box. Compared to yesterday (1-5ºC outside temps), today (6-7ºC outside temps) the inside of the battery box (after a similar run of some tens of miles) can be felt much colder. Total weight moved from front to rear, toolboxes included, is around 42 kg / 92 lbs. Best roadholding is when gas tank (placed amidships, well inside the wheelbase) is half full, not full to the brim. This is not due to fuel weight itself, but to fuel sloshing left-right in tight turns; when tank is full, it can be felt and it's annoying. With half tank it's not. Side note: all front wheel driven GTI cars are flawed from using small family car chassis and bodywork. Which had been designed for best weight balance when fully loaded. This is the reason for all efforts to balance the weight distribution. Judging by cost, labor, reliability problems, a hybrid battery with supercaps is more or less a gimmick. Its only visible advantage is light weight. Even giant 2000-3000F caps are not great in this matter, since they approach in weight a small lead-acid battery anyway. For people who seek a reliable car and they're not too much interested in brisk handling, the 150+ year old lead-acid is far more profitable. Last edited by Nautilus; 02-03-2017 at 12:43 PM..