Battery Tender?

[GrahamClark_60-68]

On my lightly used cars (driven once a week, once every other week), I've found that my battery life is improved if I keep it on the tender. My thoughts are if a battery is allowed to discharge for a week, 2 weeks, or more over and over again between drives and charging, it loses its ability to take a full charge sooner in its overall lifespan. Before I was using a tender on a regular basis, seems like I was going through batteries every two years or so, and dealing with no-starts more often than I cared. Now with my regular tender use, I've managed to extend this lifespan much closer to my daily driven experience, I believe. Not a large dataset I recognize, just my personal experience, FWIW.

 

[Nick Sticks]

I feel like there is too much stress on this. The emira is a modern car and should work like a modern car- as in you can drive it around, park and drive again.

I think the trickle charger is there because it’s clear that the emira is mostly a 2nd 3rd or 4th car so may not be driven much in which case trickle charger makes sense. Also given Lotus you don’t want the battery to go wonky since the electronics are finicky as is. But there must be some reasonable guideline on when to use the trickle charger, winter hibernation? Yes. Maybe not driving for at least 2 weeks?

The main handbook says:
With normal daily use, it should not be
necessary to use a battery charger. In
low usage conditions, it is important to
maintain the battery charge state using
a suitable trickle charger, or automatic
battery management conditioner.

and

Starting difficulties may be
experienced after an unused period of
18 days approximately.

So it's a reasonable period but as someone else says, too many times fully discharging the battery doesn't do it's lifespan any good.

 

[Rupes]

My Lotus battery tender was not included in the sale of my car - supposedly it is backordered and will be shipped to me. I have a Battery Tender from ~2015 that I used on my E92 M3 for some time. Would this work (one time) to bring the battery back to full charge while I await the Lotus charger?

Not sure if the advances in battery tech make this a concern or not.

 

[scc.131.fe]

Would this work (one time) to bring the battery back to full charge while I await the Lotus charger?

I believe there are two things that could matter, happy to have anyone else support or correct this:

1) what is the peak output amperage on your 2015 Tender? The Lotus branded version is a 4 amp output. if yours is equal to 4 or less, it would charge your car at equal or less rate, which should be fine. If you have a 5 or 7 or 9 amp charger, that increased rate may have an impact on your battery. Would that impact be made on 1 charge, or 5 or 100 charges, dunno.

2) Is your 2015 charger specified as compatible with AGM batteries? Call Battery Tender if you're not sure. If documentation or a call suggests it was not made as a unit intended for AGM, then I would spend the $50-90 for a new Tender or CTEK to use in the meantime.

Just my four cents. (inflation...)

 

[Rupes]

I believe there are two things that could matter, happy to have anyone else support or correct this:

1) what is the peak output amperage on your 2015 Tender? The Lotus branded version is a 4 amp output. if yours is equal to 4 or less, it would charge your car at equal or less rate, which should be fine. If you have a 5 or 7 or 9 amp charger, that increased rate may have an impact on your battery. Would that impact be made on 1 charge, or 5 or 100 charges, dunno.

2) Is your 2015 charger specified as compatible with AGM batteries? Call Battery Tender if you're not sure. If documentation or a call suggests it was not made as a unit intended for AGM, then I would spend the $50-90 for a new Tender or CTEK to use in the meantime.

Just my four cents. (inflation...)

Thanks for this feedback. The peak amps in my tender are 1.25 (!!!), and it was getting very hot, so I decided to just unplug it and wait until I get the one from Lotus.

 

[scc.131.fe]

Thanks for this feedback. The peak amps in my tender are 1.25 (!!!), and it was getting very hot, so I decided to just unplug it and wait until I get the one from Lotus.

Not surprised. I think I have the same one and tried to charge my 540i with a large H8 AGM battery last week. After two days it still wasn't at 80% and, man, that thing was HOT. I think those <2 amp units should really be considered "maintainers", not chargers.

 

[DJFirstEdition]

My Lotus battery tender was not included in the sale of my car - supposedly it is backordered and will be shipped to me. I have a Battery Tender from ~2015 that I used on my E92 M3 for some time. Would this work (one time) to bring the battery back to full charge while I await the Lotus charger?

Not sure if the advances in battery tech make this a concern or not.

Mine either, so I came here looking for someone who was told the same thing.

I am a little annoyed. I thought it was shady of the dealer to tell me after we completed the sale, and I signed the paperwork with "nothing owed" instead of a due bill with the Lotus-branded charger that I paid for.

I am wondering if you ever got yours.

(Now, back to the thread to see what I should do. Mine will undoubtedly sit for long periods at different points of the year.)

Edit:
After re-reading the thread from top to bottom, I picked up the BatterymindER (brand name) 4 amp. I haven't cracked open the battery box, but from the pictures in the threads, it doesn't seem that difficult to sort out.

As always, thank you for sharing our experiences and helping other owners. New Lotus guys like me appreciate learning from the guys/gals who have been there and done that.

 

[Rupes]

I am wondering if you ever got yours.

I did. It was mailed to me as promised without any additional followup from me.

 

[DJFirstEdition]

I did. It was mailed to me as promised without any additional followup from me.

Thank you. I hope my dealer is as honest or good as yours.

 

[seriously]

My dealer is still “back ordered”

 

[morphious]

Thank you. I hope my dealer is as honest or good as yours.

If not mistaken, I believe you got your car from Galpin as did I. When we signed all the paper work we signed a parts missing form stating what was missing on the car vs. what was listed on the window sticker. I received a UPS tracking email saying a package is being delivered to me from Galpin next week which I assume should be the charger, we will see.

 

[Bulls-Vivid-Red]

My dealer is still “back ordered”

My dealer is Glenview IL and I haven't heard a peep from anyone as to my missing battery tender. Nice to hear that some people have had theirs mailed to them, I'll reach out to my dealer to share this "discovery" and see if they can replicate for me.

 

[DJFirstEdition]

. I received a UPS tracking email saying a package is being delivered to me from Galpin next week which I assume should be the charger, we will see.

How long ago did you get your car?

He said they were back-ordered and going out as the cars did.

I am not super vexed about this or anything. I really just came to figure out if they were really back-ordered (the answer is yes) and what people were doing in the meantime (thanks for that - be sure you get 4amps and not just a 'trickle charger')

 

[morphious]

How long ago did you get your car?

He said they were back-ordered and going out as the cars did.

I am not super vexed about this or anything. I really just came to figure out if they were really back-ordered (the answer is yes) and what people were doing in the meantime (thanks for that - be sure you get 4amps and not just a 'trickle charger')

I picked up my car on 6/9/24, did they tell you that they would mail you one? If not, call your sales person and they should take care of it, as Galpin has been very transparent with me through out the whole process.

 

[DJFirstEdition]

I picked up my car on 6/9/24, did they tell you that they would mail you one? If not, call your sales person and they should take care of it, as Galpin has been very transparent with me through out the whole process.

He said he would call me when they come in. I feel a little bit better after reading that you bought from them and they made good.

My sales guy was Arnold. Did the whole "unveil the car via the vault" gimmick? It was fun.

 

[DJFirstEdition]

He said he would call me when they come in. I feel a little bit better after reading that you bought from them and they made good.

Update: They didn't call me but sent it via UPS automatically just a week later.

 

[NorCalEmira]

I received my Lotus battery tender by mail within a few weeks of purchase.

 

[Bulls-Vivid-Red]

My dealer is Glenview IL and I haven't heard a peep from anyone as to my missing battery tender. Nice to hear that some people have had theirs mailed to them, I'll reach out to my dealer to share this "discovery" and see if they can replicate for me.

Despite me reaching out, still complete radio silence from my dealer here in Chicagoland.

Any type of response at all would have been appreciated......being ghosted for something so trivial makes me wonder how things will go with any serious issues down the road.

 

[VroomPop]

I didn't disconnect anything when installing the tender. Just connected the ground first, removed the inline fuse from the + lead, connected it to the positive terminal, then re-installed the fuse, no issues or codes. I've had it for over 3 months.

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How did you get the cover off the positive side? I'm having a heck of a time trying to get that plastic cover out of the way. Thanks for any help and pics.

 

[Time2Fly]

It unclips on the front and on the side. I fitted the pigtail for my tender under it and out towards the back from one of the hinge gaps.