AH battery drain

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[ericmark]

The charger I selected was designed for one battery but there are chargers designed for two batteries. But for what is required can't see it's required. The idea of twin outlets is where the usage of the two batteries are different.

I do find the word battery can confuse. A battery is a collection of similar items be that guns or cells. So putting two sets of 6 cells all connected together is still a battery. But put two sets of 6 cells as two groups of 6 would be batteries. Same with guns can have north battery and south battery together their batteries.

Putting cells in parallel as already said can cause problems with one bad cell draining a good cell but weight has to be considered and in order to accommodate the weight in a small boat like a canoe I would consider a port and starboard battery would make sense.

However 6 volt battery start at around 180AH at a 5 hour rate and weigh 37kg where as a 12 volt start at around 51AH at a 5 hour rate and weigh 22.1Kg so although theory may be two 6 volt units in practice it may be better to use 12 volt units. Firms like this one advertise reconditioned and used batteries and that may be the better route. Also they will provide the connectors needed to remove and refit batteries with ease. I would also suggest a visit to a disability centre as the batteries used with wheel chairs and scooters are likely the size and type you need.

 

[bernardgreen]

I would consider a port and starboard battery would make sense.

One step further would be to two 6 volt batteries on each side, one forward and one aft of the seat. Thi would move the wieghty items evenly away from the widest part where the seat is normally fitted.

 

[ericmark]

I would consider a port and starboard battery would make sense.

One step further would be to two 6 volt batteries on each side, one forward and one aft of the seat. Thi would move the wieghty items evenly away from the widest part where the seat is normally fitted.

I would agree except as I said if you look at traction batteries the 6 volt versions are much larger than the 12 volt versions. So I would think although in theory two 6 volt units would be best in practice likely two 12 volt units would have to be used.

The same problem was found with my sons narrow boat. Single cells of 330AH are hard to buy and very expensive and a 330AH 12 volt battery would be too heavy. So three 110AH batteries were fitted and connected in parallel. It is the only real way to do it. The forth battery was separate and used for engine starting. The only thing one can do is buy all batteries to be used in parallel together.

You will find things like the larger Ford Transit now use two 12 volt batteries in parallel from new. Only the older vehicles like the Land Rover used two 6 volt units. Even then I think it was more to do with location. One under bonnet and one under seat would mean the cables would be different lengths so unless in series they would not get even use.

Which is of course a good point to make. Cable lengths with batteries in parallel should be the same both using and charging.