BMW battery tender question.

[c watson]

I picked up the Everstart H7 AGM battery this past week and I was wondering if my BMW Advanced Charging system tender would be safe to use. This is an AGM battery and I’m not sure if the mentioned trickle tender would work on AGM.

I have the cigarette lighter version which is very easy to use.

Thanks

[Arith2]

Whats the part number of the tender?

[c watson]

Whats the part number of the tender?

82110026663

[Arith2]

The amperage is fine, but it doesn't shut itself off. I would highly advise getting a tender that knows when to stop. That charger was made before BMW started using AGMs in their vehicles.

[c watson]

The amperage is fine, but it doesn't shut itself off. I would highly advise getting a tender that knows when to stop. That charger was made before BMW started using AGMs in their vehicles.

Thank you. I think it’s time to upgrade to a C Tek or a newer BMw version.

[ugaexploder]

Thank you. I think it’s time to upgrade to a C Tek or a newer BMw version.

I recommend getting a Noco one off Amazon. You can also buy it with Amazon's warranty and probably never have to worry about it again. I have both the 10A and 1A versions.

[Xmetal]

I recommend getting a Noco one off Amazon. You can also buy it with Amazon's warranty and probably never have to worry about it again. I have both the 10A and 1A versions.

How are you connecting your Noco chargers to your car? At the underhood terminals or at the battery terminials in the trunk? I have the genius10A charger and when I use the underhood terminals, it thinks my battery is fully charged and goes into tender/trickle mode after only about 5 to ten minutes. It stays in tender/trickle mode until the battery is actually topped off, which takes another 8 or more hours. It behaves this way on both of my BMWs when using the underhood terminals. The CTEK works much better when using the underhood terminals - it stays in charging mode until the battery is actually topped off before it enters tender/trickle mode. The NOCO, however, works as expected when connected directly to the battery.

[ugaexploder]

How are you connecting your Noco chargers to your car? At the underhood terminals or at the battery terminials in the trunk? I have the genius10A charger and when I use the underhood terminals, it thinks my battery is fully charged and goes into tender/trickle mode after only about 5 to ten minutes. It stays in tender/trickle mode until the battery is actually topped off, which takes another 8 or more hours. It behaves this way on both of my BMWs when using the underhood terminals. The CTEK works much better when using the underhood terminals - it stays in charging mode until the battery is actually topped off before it enters tender/trickle mode. The NOCO, however, works as expected when connected directly to the battery.

I've been solely using the posts under the hood. I haven't really paid that close attention to what it's doing after hooking up but it seems correct as it shows it topping off the charge and putting it in tender mode.

I know that these AC chargers for DC batteries can generate ripple currents so there may be some temp sensor in these devices that might change what mode it's in, not necessarily dictated by the capacity...not much in the auto industry to even detect that kind of thing, but I'm not too worried about it.

May have to take a closer look at what it's doing...thanks for the heads up 🤝

[siamkazi]

Sort of related, my car sits outside for long periods of time but no outlet nearby. Picked this up recently and it's been pretty solid.

[Xmetal]

I've been solely using the posts under the hood. I haven't really paid that close attention to what it's doing after hooking up but it seems correct as it shows it topping off the charge and putting it in tender mode.

I know that these AC chargers for DC batteries can generate ripple currents so there may be some temp sensor in these devices that might change what mode it's in, not necessarily dictated by the capacity...not much in the auto industry to even detect that kind of thing, but I'm not too worried about it.

May have to take a closer look at what it's doing...thanks for the heads up 🤝

Do you ever see a single solid green light? If not, and only see a blinking green light, then your battery hasn't been topped off yet as it's still in the trickle charging/tender mode. Your battery is only completely charged (topped up) if you see a single solid green light (LED).

[Xmetal]

Sort of related, my car sits outside for long periods of time but no outlet nearby. Picked this up recently and it's been pretty solid.

Great idea - I have a car that sits outside and this seems perfect for that. Unfortunately, there's one on sale right now with the cigarette lighter option for about 45% off, but it's sold out

[ugaexploder]

Do you ever see a single solid green light? If not, and only see a blinking green light, then your battery hasn't been topped off yet as it's still in the trickle charging/tender mode. Your battery is only completely charged (topped up) if you see a single solid green light (LED).

Nice. I typically see the solid green light, and sometimes when I just put it on the charger it will be at 2 or 3 bars and sometimes different colors (orange I believe?) before it reaches the solid green light if memory recalls.

[BlueBimmers]

I've used the Nocos for years with no issues. The Genius 3500 and the smaller one.

[Xmetal]

Nice. I typically see the solid green light, and sometimes when I just put it on the charger it will be at 2 or 3 bars and sometimes different colors (orange I believe?) before it reaches the solid green light if memory recalls.

How long does it typically takes you to see that solid green light? Mine goes through those flashing bars fairly quickly even on an H8 AGM battery on one of my car!

[siamkazi]

The green light blinking, this could be a point of reference: