Thanks for the feedback 👍
That's what we're here for! 😎

Many thanks for your input lads,this as been so helpful,Dont know what I'd do without your help
Regards
Joe

Yep! Good one Dave👍
I guess that about covers it, with the input info we have. 😉
Over to you Joe, bon chance, Doug 😎

Hi Joe
I guess this is a follow on from your last request re charging batteries in the boat. Your tandem is usually referred to as parallel connected where the positive terminals on each battery are connected together as are the negative terminals. This will give you 12 volts but double the Amphr capacity in your case to 24Amphr.
Is this to be used in the fishing boat with the working winch?
As Doug advised the total expected current draw will determine the cable required and you should protect this with a fuse in the positive lead from the batteries.
If you can run separate cables from the battery to the ESC and the winch control then they will only need to carry the current for that device. Again each cable should have an appropriate fuse.
As regards the charging lead this will be less than 5 amps and your SLA will have suitable leads.
I would not recommend charging SLA's in parallel as in my experience one always charges first and the charger goes into trickle mode leaving one battery undercharged. I thinke you will need to have the two positive battery connections accessible so you can charge each separately.
Halfords have a range of cables which should cover your requirements and also have fuses.
Cheers
Dave

OK. Then you mean in parallel to double the capacity and therefore run time. Then you have to always make sure that both batteries are the same type, same age and same charge level! Otherwise the stronger one will always be charging the weaker one until they are both at the same state!
I can still only point to my previous advice, have a look at the link to 'Electrical related', cos I don't know how much current you want to stuff through the cables. in the same forum you will also find some guidelines for fuses to protect; cables, motors, ESCs, other expensive equipment!

For the record tandem to me means one behind the other like the bike! 😉 I.e. in series! Good luck, Doug 😎

Doug
I want to use 2 12volt batteries in tandem but still want a 12volt supply
Regards
Joe

Hi Joe,
depends on the current drawn! What's the ESC / motor setup?
Any other loads? Lights, other accessories?
Total possible current required?
In the 'Electrical forum I discussed which cable for what with some other members. Check if that answers your query.
https://model-boats.com/forum/electrical-related/28332

Tandem? I assume you mean in series to give 24V total supply.
Is this correct?
cheers Doug 😎