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I have been looking at battery chargers for traction or leisure batteries.
The main thing is in order to charge quickly most have a duel charge voltage and charge at a higher output until the current drops below a preset value. This value is dependent on battery size and for example a 300Ah battery will switch once current drops below 2.5A.
These chargers will only switch stage if there are no other loads on the circuit so although they may work well charging a fork lift battery in a caravan or boat they could over charge the battery.
Some do have a time limit to counter this problem but to power all the 12V from a separate power supply while the batteries are charging would be ideal method.
Up to now, every problem I have found already has a solution and I am sure there is one to this problem?
If the power required exceeds what the power supply can deliver I would still want to be able to draw power from the batteries but for maybe first 5A it would not draw from batteries. Diodes seem likely answer with 0.6V drop two diodes between battery and current using equipment would mean the battery can be charged at 14.8V and the power supply need only provide 13.6V with a mains powered normally closed relay to bridge diodes once shore power fails.
Has anyone seen such a system. I am sure some one already makes one? While using the engine it is unlikely much will be used on domestic power but it could of course so another option would be to swap batteries while being charged so domestic items are powered from the engine start battery while the domestic batteries or on boost charge. For this one would need a change over relay which is voltage triggered so as soon as the engine battery voltage drops it will default back to domestic battery.
Again I know I can make one but I am sure somewhere it is already done.
Any ideas?
Eric
The main thing is in order to charge quickly most have a duel charge voltage and charge at a higher output until the current drops below a preset value. This value is dependent on battery size and for example a 300Ah battery will switch once current drops below 2.5A.
These chargers will only switch stage if there are no other loads on the circuit so although they may work well charging a fork lift battery in a caravan or boat they could over charge the battery.
Some do have a time limit to counter this problem but to power all the 12V from a separate power supply while the batteries are charging would be ideal method.
Up to now, every problem I have found already has a solution and I am sure there is one to this problem?
If the power required exceeds what the power supply can deliver I would still want to be able to draw power from the batteries but for maybe first 5A it would not draw from batteries. Diodes seem likely answer with 0.6V drop two diodes between battery and current using equipment would mean the battery can be charged at 14.8V and the power supply need only provide 13.6V with a mains powered normally closed relay to bridge diodes once shore power fails.
Has anyone seen such a system. I am sure some one already makes one? While using the engine it is unlikely much will be used on domestic power but it could of course so another option would be to swap batteries while being charged so domestic items are powered from the engine start battery while the domestic batteries or on boost charge. For this one would need a change over relay which is voltage triggered so as soon as the engine battery voltage drops it will default back to domestic battery.
Again I know I can make one but I am sure somewhere it is already done.
Any ideas?
Eric
