Battery Tender

Simple question. I know the eletronics on the SD are sensitive.
I want to use a battery tender on the bike for long storage, but....
Do I have to use the KTM tender or can I use an off shelf one?
I have a quick connect on my Honda and it is very convinient.
The manual says that if I want to use a tender, I should disconnect the battery before I charge it.
Is it true or just Company BS trying to sell their product.
I like the quick connect and don't want to keep disconnecting the battery to connect the tender if I am not going to ride for a month or so....

i've just got a cheap £15 trickle charger on mine mate and does the job just fine.

i've got a battery tender jr., i leave mine plugged in 24/7, you do not have to unhook the battery to trickle charge, my bikes a left over '07 which sat on the showroom floor forever, and original battery is going strong

I use a 'battery fighter' and its all good, plugged in 24/7 while not ridden. Just KTM trash talk trying to get you to spend money on their charger.

That's exactly what I thought....Corporate BS.
Thanks for the info

Battery Tender- is that to say, beat me up but be gentle and do it with love?

I was given £50 in Hein Gericke vouchers for Xmas and am waiting for them to get some Optimate IV back in stock. It's the only thing I could see from their site that was worth buying.