24 volt battery chargers

place the batteries in parallel and charge both at once

Yer Ivan, they are wired to run a 24 volt electric motor, so at the plug is 24 volts

ray t1
Because the output of a Ctek is autonomous, ie not connected to anything but itself, simply buy a second charger, same as, and have it connected across the other battery.
When connected there will be one red and one black clip on the centre link.
Both chargers then plugged into same 240v source or 240v with timer control if required, the chargers can be left on there until you float the boat.
That will save opening the connecting series heavy link cable joining the two and remembering to rejoining again when trying to juggle 12 charger to do both at same time.
Pump motor won't be affected as it only sees the 24v total.

https://www.jaycar.com.au/12v-7-2a-24v-3-6a-9-state-charger/p/MB3613?utm_campaign=redirect&utm_source=MB3606r&utm_medium=web

I have it's older brother and it works fine

I use a Minn Kota MK2 onboard battery charger and love it. It will charge both batteries while the boat is running off the boat motor. When I get home I just connect a charger to the 12v auxiliary battery to top it up and the Mk2 will automatically top up the other 2 batteries (24 volt system) at the same time. The only thing you need to do is have isolator switches because, as the charger is always connected, it draws a minute (I think milliamps) amount of power to analyse if it should be charging or not. Not normally an issue but may drain the battery if not using the boat for 6 months or so.
I currently have 4 batteries in my boat and charge all 4 at once. 2 run at 12 volt and 2 in series running at 24 volt. I basically have the same dual battery system you would have in a car. Starter battery being charge off the alternator which is then connected through a redarc to the auxiliary to run all the accessories. This auxiliary is then connected to the MK 2 charger which chargers 2 x 12v in series batteries.

Hope this helps.

Tony

Very interesting, cheers

.
Hi Ray,

There are countless 24 volt battery chargers available. I cannot understand why anyone would want to muck around with fiddly reconnection in order to employ a 12v charger.

Google "24 volt battery chargers" and you will have many to choose from. Pointless in me making a specific recommendation. Fix a budget price then select a supplier that you feel confident with.
N.B. the cheapest may not be the wisest purchase.
If you like, make a selection then post it here for me and others to pass judgment.

Two identical 12 volt chargers linked in series will charge a 24 volt battery set up.
Treat the chargers as if they were batteries with the positive lead of one connected to the negative lead of the other. Used this for years to charge light aircraft 24volt batteries.