F800GT battery charging advice please

[LeeJo]

Hello,

 

I have a 2015 F800GT. I have a smart battery charger from my last bike and I’d like to connect this directly to the battery to trickle charge it.

 

I think I read somewhere that BMW don’t recommend this, has anybody done this and did it work out OK?
 

thanks!
 

lee

 

 

 

[Yorky]

I have an optimate connected to my 1250. It's been on it since around October and no problems.

 

[Bender]

A battery optimizer and a battery charger are different things? 

[Gerontious]

8 minutes ago, Bender said:

A battery optimizer and a battery charger are different things? 

The OP describes it as a Smart Charger which I imagine is the same thing. Would be helpful if he told us exactly what it is. As for the actual question there is no reason not to connect it directly to the battery!! I had an F800S and my optimate was connected in this way.

 

This assumes it’s a standard battery and not an upgraded Lithium. In which case you MUST use a lithium charger.

Edited April 1, 2022 by Gerontious

[Bender]

27 minutes ago, Gerontious said:

The OP describes it as a Smart Charger which I imagine is the same thing. Would be helpful if he told us exactly what it is. As for the actual question there is no reason not to connect it directly to the battery!! I had an F800S and my optimate was connected in this way.

 

This assumes it’s a standard battery and not an upgraded Lithium. In which case you MUST use a lithium charger.

I have a smart charger, it detects 12v or 6v and that's it. Tbh it's not that smart and does not do battery maintenance and comes with the disclaimer not to leave permanently connected, it's obvs not that smart... 

[Stu]

Connect it straight to the battery it will be fine. 

 

The manual will tell you that you can't do this and you have to buy a bmw charger to go through the din socket and will work with the canbus system. 

 

It's bollox really 

[Mississippi Bullfrog]

I use CTEK chargers on my bikes and they are connected permanently to the batteries via fly leads. But I don't have them switched on 24/7. They are plugged into a timer switch which turns them on two hours a day. 

 

It's probably being over cautious but it works for me. 

[Stu]

1 hour ago, Mississippi Bullfrog said:

I use CTEK chargers on my bikes and they are connected permanently to the batteries via fly leads. But I don't have them switched on 24/7. They are plugged into a timer switch which turns them on two hours a day. 

 

It's probably being over cautious but it works for me. 

 

This is probably worse for the battery than keeping it plugged in all the time 

 

Every time the charger is turned on it will charge the battery first before going in to a test mode then switching to maintenance mode 

 

Charging will be applying higher volts for a good 30 mins then it will test for 30 mins or so before going on to maintenance mode and holding it a float charge 

 

I would just plug it in and forget about it as your method could lead to over charging 

 

They are made to fit and forget 

[Mississippi Bullfrog]

1 hour ago, Stu said:

 

This is probably worse for the battery than keeping it plugged in all the time 

 

Every time the charger is turned on it will charge the battery first before going in to a test mode then switching to maintenance mode 

 

Charging will be applying higher volts for a good 30 mins then it will test for 30 mins or so before going on to maintenance mode and holding it a float charge 

 

I would just plug it in and forget about it as your method could lead to over charging 

 

They are made to fit and forget 

Well it seems to work quite well for me. The OEM battery in the Bobber is a bit naff and most fail within a year or two. Mine still has the original 4 years later. The Honda battery is at least 7 years old. 

 

A bike that is used every day gets the battery charged at higher voltage on a daily basis and from experience batteries seem to last longer that way. The batteries in our cars last longer in the daily use car than the one that's used less frequently.  My last one lasted 21 years getting a charge every day. 

[Stu]

1 minute ago, Mississippi Bullfrog said:

Well it seems to work quite well for me. The OEM battery in the Bobber is a bit naff and most fail within a year or two. Mine still has the original 4 years later. The Honda battery is at least 7 years old. 

 

A bike that is used every day gets the battery charged at higher voltage on a daily basis and from experience batteries seem to last longer that way. The batteries in our cars last longer in the daily use car than the one that's used less frequently.  My last one lasted 21 years getting a charge every day. 

 

I don't know why I put volts I meant to put amps as its the amps that kills the batteries 

 

Once cars and bikes are running you will have the same volts but higher amps to start with to bring the battery up to a fully charged state the reg/rec then dissipates that as heat so it doesn't over charge the battery 

 

Holding a battery at 13 - 14 volts is fine but sticking too many amps in is what over charges them and kills them 

 

Hence the need to not have a car running when jumping off a bike battery as the up to 450 amps that can be ploughed in to the battery will just fry it 

 

I'm not saying that your way will kill the battery but I would prefer to fit and forget as the chargers where intended to do 

 

I had 11 years out of the original battery on the TL1000 the FJR battery is 10 years old and as far as I know still going strong and I believe the BM to be on the original battery so lets see how that fairs but I don't know the history of that battery there was no evidence of a charger being attached but it could have had the BMW charger attached to the din port for all I know 

[Capt Sisko]

Hi, I've got both a F800GT and an Oxford Oximiser 3x wired direct to the battery via the socket they provide.

Not problems whatsoever.