Are they man enough for what they are wired up to?
I would suggest no... I bought my 250 last year and had dual batteries fitted.
I left one battery to supply the starter and the windlass and the bow thruster.. Although on boats supplied with just one battery it supplies everything.!!!
The second supplied the house electrics.. (Navionics, lights, stereo etc)
Last year a couple of times when manoeuvring up and down the side of anchored tankers I had to keep on and off the bow thruster.. A few times it made a grinding/grating noise and failed to operate..
Even though the engine was running the power consumption was draining the battery reserves flat..
Today I started and used the windlass to retrieve 50ft chain and 80 ft rope, by the time it had got it up the battery was knackered enough that the bow thruster once again didn't want to know..
The batteries supplied are the cheapest highest Ah capacity batteries you can find and once again shows the penny pinching mentality of Arvor/EBY..
These 110ah batteries can be bought for less than £60, vs the cost of circa £200 for a top of the range Optima.
For the sake of £140 more when spending £70k vs the reliability and performance of using optima it would make sense to fit Optima as standard..
Gripe over... Ordered 2 x 75aH Optimas 10 minutes ago..
PS: Should have changed them last year when I bought the boat as standing reading was only 12.3 volts even after being fully charged with an external charger. And with low voltage alarm set to 11.5 volts, it will sometimes go off if I have the plotter on, stereo, heater and then use the VHF.. In short... Cr*p batteries..