Hi there,
I have recently become the boat manager for Somerset Waterways, Taunton, Somerset, UK. I am looking after a 2.5 ton, 12 passenger trip boat that is powered by an Agni Lynch motor (probably a 95, but I have not found a works plate yet to verify this). The boat is three years old. The battery pack is a Powercell 600Ah 24v set, and is not in very good shape at all, due to very poor battery management.
I have no end of 'challenges' with the technical side of this boat - I feel that some of them might have been avoided with some level of technical understanding by the users earlier in the life of the boat, but whatever, I would welcome some opinions on what I have discovered so far.
The Agni is linked directly to the prop shaft - the boat is a canal and river cruiser, not a speed boat, so I would estimate the prop shaft rpm (and thus the motor rpm) as perhaps 250 rpm cruising, maybe 400 max (rarely used). My concern is that there is an awful lot of heat being chucked out by this motor. Someone has installed a thermometer remote sensor about 2 cm away from the motor casing, which records (during the course of a half hour journey, at an estimated 250 rpm, drawing 35 Amps) a gradually increasing temperature, eventually topping out around 65 degrees Centigrade - the thermometer does not record more than 70, which is not useful.
There is evidence of heat damage to the plastic end cap around the power connections. There has been evidence, in the form of excessive heat and a hot-electric-motor type smell, of overheating when the power is pushed up to 50 or 60 amps for any protracted period.
The motor and prop shaft turn easily and freely, much as they have always done - we are not in seize-up country.
As a design 'feature' the motor has no external air flow at all, with the floorboards in place. One of my first concerns is to remedy this - which I find quite amazing (is the polite way of putting it!).
I would really welcome the opinions of anyone with technical knowledge, on the various matters that this installation raises:
Theoretically the motor is rated at 100 Amps. If I ran it like this for a couple of minutes, I am sure I would burn it. Is maximum current limit actually limited, in real life, by the speed of airflow through the motor, and thus by the rpm? If so, is there something technical I could read somewhere to 'learn the rules'?
I am thinking of cutting (inbound) vent slots in the floorboard panel, installing a 24 volt truck radiator fan, with a thermostat, and providing some form of ducting arrangement to get the heat out of the small, unventilated space that the motor lives in.
Really, the whole installation is far to 'lightweight' for a boat that is allowed out on a river - 2.4Kw supposed maximum power - smaller than the smallest outboard. Unfortunately, upgrading or replacing the drive line components with something meatier is not an option - I have to make do with what I am given.
Any comments anyone?
Ken Bussell
I have recently become the boat manager for Somerset Waterways, Taunton, Somerset, UK. I am looking after a 2.5 ton, 12 passenger trip boat that is powered by an Agni Lynch motor (probably a 95, but I have not found a works plate yet to verify this). The boat is three years old. The battery pack is a Powercell 600Ah 24v set, and is not in very good shape at all, due to very poor battery management.
I have no end of 'challenges' with the technical side of this boat - I feel that some of them might have been avoided with some level of technical understanding by the users earlier in the life of the boat, but whatever, I would welcome some opinions on what I have discovered so far.
The Agni is linked directly to the prop shaft - the boat is a canal and river cruiser, not a speed boat, so I would estimate the prop shaft rpm (and thus the motor rpm) as perhaps 250 rpm cruising, maybe 400 max (rarely used). My concern is that there is an awful lot of heat being chucked out by this motor. Someone has installed a thermometer remote sensor about 2 cm away from the motor casing, which records (during the course of a half hour journey, at an estimated 250 rpm, drawing 35 Amps) a gradually increasing temperature, eventually topping out around 65 degrees Centigrade - the thermometer does not record more than 70, which is not useful.
There is evidence of heat damage to the plastic end cap around the power connections. There has been evidence, in the form of excessive heat and a hot-electric-motor type smell, of overheating when the power is pushed up to 50 or 60 amps for any protracted period.
The motor and prop shaft turn easily and freely, much as they have always done - we are not in seize-up country.
As a design 'feature' the motor has no external air flow at all, with the floorboards in place. One of my first concerns is to remedy this - which I find quite amazing (is the polite way of putting it!).
I would really welcome the opinions of anyone with technical knowledge, on the various matters that this installation raises:
Theoretically the motor is rated at 100 Amps. If I ran it like this for a couple of minutes, I am sure I would burn it. Is maximum current limit actually limited, in real life, by the speed of airflow through the motor, and thus by the rpm? If so, is there something technical I could read somewhere to 'learn the rules'?
I am thinking of cutting (inbound) vent slots in the floorboard panel, installing a 24 volt truck radiator fan, with a thermostat, and providing some form of ducting arrangement to get the heat out of the small, unventilated space that the motor lives in.
Really, the whole installation is far to 'lightweight' for a boat that is allowed out on a river - 2.4Kw supposed maximum power - smaller than the smallest outboard. Unfortunately, upgrading or replacing the drive line components with something meatier is not an option - I have to make do with what I am given.
Any comments anyone?
Ken Bussell