Deltran Battery Tender or CTEK SmartCharger

Originally Posted by Thunder Dump

1+1 for Deltran. I've got this one:



This will be my fourth winter with it (car lives most of the snowy months sipping on the tender) and it has been flawless. Highly recommended, especially at this price point.

I have the same model. My third year with it, no issues.

Originally Posted by Nordic_Kat

First of all, I want to send out a big thanks to everyone who gave their input regarding both of these units. This was a very hard decision as they are so similar and as many of you stated it would be hard to mess up, going either direction. I finally ran it by a co-worker who has prior extensive experience keeping lead-acid batteries healthy for things like nuclear subs and batteries that were on the Space Shuttle. He said it was a coin toss between the two units, but gave a slight nod to the CTEK unit, mostly for the purdy lights.

I pulled the trigger and hope to have the unit in a week. I plan on experimenting a bit with it a'la ILMC's comments about hooking it up and watching it kick into action with things like opening and shutting doors and actuating the top.

Interesting to me is that some of the extra-curricular reading generated by the links provided by Galahad turned up 5 series and 7 series owners experiencing the same shock and puzzlement I experienced that the simple act of opening the driver's door and not turning the car on causes a huge gulp of battery juice to feed the system computers. Looks like this is a 'feature' on current model BMWs in general. I will have to go back over my owner's manual with a fine tooth comb because, while I do remember reading that actuating the top more than 5 successive times without the engine running could cause a significant drain on the battery, I never remember seeing that same warning about opening and closing the driver's door.

Again, thanks to all who helped me sort this out, your assistance is much appreciated.

Well, change my vote from the Battery Tender to the CTEK. That now makes it CTEK 14, Battery Tender 13.

My wife started reporting that she was having the low battery warning periodically. She's been working a lot for a couple of months now, usually 7 days a week getting the financials ready for the auditors and tax preparers, so the car is pretty much being drive 10 miles to and from her office with no time for weekend canyon carving or any longer trips. About a week ago we went out for take-out and while she was sitting in the car with the radio on the car shut down. Fortunately, it started right up when I returned with the food, but it's clear that her battery need recharging. I also decided on the CTEK 3300 and it arrived today. There are only three modes with one mode indicated as the "normal setting" and another mode indicated as being "recommended for many AGM batteries like Optima, Maxxima, and Odysses".

So for the BMW OEM battery in an E92 should the mode be set to "Normal (14.4V)" or the AGM mode (14.7)?

Where are you guys picking these up from? I'm thinking of getting one because I get the battery symbol if I leave my radio on for less than a minute after shutting the car off. I have a 5 mile commute and in most cases my car isn't warmed up by the time I reach work. But I do a lot of 20-30 mile drives on the weekends and in the evenings.

I've also noticed that my CA for lowering the convertible top doesn't work in the morning and I think it might be related to the battery being low on juice.

Amazon.com.

Originally Posted by unrealii

Where are you guys picking these up from? I'm thinking of getting one because I get the battery symbol if I leave my radio on for less than a minute after shutting the car off. I have a 5 mile commute and in most cases my car isn't warmed up by the time I reach work. But I do a lot of 20-30 mile drives on the weekends and in the evenings.

I've also noticed that my CA for lowering the convertible top doesn't work in the morning and I think it might be related to the battery being low on juice.

CTEK 3300 on Amazon, $55.00, Prime

CTEK 7002 on Amazon, $96.98, Prime

Can anyone with a CTEK 3300 tell me in which mode they set it for an E9x?

Originally Posted by SD Z4MR

Can anyone with a CTEK 3300 tell me in which mode they set it for an E9x?

I personally use the AGM/winter mode for my BMW, because I believed my black battery to be AGM. I also charge more frequently in the winter. Even at the higher voltage, it still always takes several hours or significantly longer, though thankfully it hasn't gone 24 hours like the first time (and I didn't have any dash warnings at all to begin with; IOW I won't be very surprised if your first charge goes even longer than 24 hrs, even when using the AGM mode).

You would have to confirm, but I think the higher rate is fine even if your battery wasn't AGM, if the weather was "cold". I personally use the lower/normal rate on my truck. As far as I know, my BMW is still using the original battery, the car is over 5 y.o., and everything seems to be working just fine. The 7002 is capable of an even higher voltage at 15.7, but I'm sure you already knew that.

Originally Posted by Ilovemycar

I personally use the AGM/winter mode for my BMW, because I believed my black battery to be AGM. I also charge more frequently in the winter. Even at the higher voltage, it still always takes several hours or significantly longer, though thankfully it hasn't gone 24 hours like the first time (and I didn't have any dash warnings at all to begin with; IOW I won't be very surprised if your first charge goes even longer than 24 hrs, even when using the AGM mode).

You would have to confirm, but I think the higher rate is fine even if your battery wasn't AGM, if the weather was "cold". I personally use the lower/normal rate on my truck. As far as I know, my BMW is still using the original battery, the car is over 5 y.o., and everything seems to be working just fine. The 7002 is capable of an even higher voltage at 15.7, but I'm sure you already knew that.

Thanks, everything I was able to find seemed to indicate that it was an AGM battery but I just wanted some verification from someone who actually used the CTEK 3300 in that mode. I did get confirmation that the battery in my M Roadster is also an AGM battery so it also seemed to follow that the E9x battery was an AGM. As far as being cold, the overnight lows here have been in the lower 40's. I consider that cold!

I was also surprised that the terminals in the two cars differed so much. In my M Roadster the positive and negative terminals are large hex bolts and it appears that I may be able to unscrew them and mount the eyelet connector permanently, but in the 335is the positive terminal is a large c-shaped piece of copper and the negative terminal is a post that looks like it's a reverse torx bolt that's threaded internally. It looks like I could drill the positive copper terminal and bolt the eyelet connector to it. I'll have to investigate more tomorrow.

Although you got the battery replaced and don't care about the old dead one anymore, I'd say the battery is bad. My tacoma battery doesnt hold a charge after a couple of days. I had 3 people all run diagnostics on it even thinking it was a short. Batteries dont last forever and sometimes are built to last a day. :lol:

Also, has anyone used the solar chargers?

Originally Posted by raphen325i

Also, has anyone used the solar chargers?

Yes. They work well. But not at night, in the shade, or when it's raining.

Bwaaahaaahaaahaaaaaaaaa! I scorn your puny battery tenders!

Some more q's.

My battery light comes on if I leave the car in acc for a while. I have an apt next week with my dealer to look into this as well as some other non-related issues.

If they refuse to replace the battery I plan to recondition it with the ctek 7002. With that -

1) Do I need to disconnect the battery from the car? Are the pulses for desulfation safe for the car's electronics?
2) If the battery becomes magically like new again, would the car properly adapt its charging algorithms (old vs reconditioned battery)?

Originally Posted by unrealii

Some more q's.

My battery light comes on if I leave the car in acc for a while. I have an apt next week with my dealer to look into this as well as some other non-related issues.

If they refuse to replace the battery I plan to recondition it with the ctek 7002. With that -

1) Do I need to disconnect the battery from the car? Are the pulses for desulfation safe for the car's electronics?
2) If the battery becomes magically like new again, would the car properly adapt its charging algorithms (old vs reconditioned battery)?

1. Yes, it goes to higher voltage. I totally removed mine but you could just disconnect the negative terminal (that's what I did on my lawn tractor)

2. It won't be totally as-new; mine tested to 43Ah and is labelled a 90Ah battery. After reconditioning via CTEK the car still had issues in the first week. At that point I installed a new battery (no registration). It still had issues for at least a week but on testing at the end of the second week all was fine. From this I deduce the car eventually figured out it had a different battery

When a DCAN cable arrived I registered my battery. What you decide to do is up to. Technically it should be a new battery and registration. Personally next time I will go the recondition route and run the car a few weeks to see if it improves.

Looks like you had the white - non-agm battery. What was the Ah after you tried to recondition it? What type of errors were you getting?

I spoke to my mechanic and he said it isn't good to leave these cars disconnected because they will throw some codes. He didn't seem convinced about my plan to recondition the battery. I still think its worth a shot if I can make this battery last a year or two longer. Wondering if I should hook up a trickle charger to the car when the battery is disconnected.

Thoughts?

Originally Posted by unrealii

Looks like you had the white - non-agm battery. What was the Ah after you tried to recondition it? What type of errors were you getting?

Yup 90Ah lead acid, I measured 43Ah IIRC (I'd bet a brand new one measures at well below 90Ah). Car would run rough when started and jerk for the first mile up a small hill in the neighborhood. Left with ignition on/ engine off the yellow battery light appeared within about two minutes.

Originally Posted by unrealii

I spoke to my mechanic and he said it isn't good to leave these cars disconnected because they will throw some codes.

Briefly saw the yellow car on lift symbol. It soon disappeared. INPA shows these codes were thrown once each:
D690 1 Error Stored 20
A559 1 Error Stored 20

Originally Posted by unrealii

He didn't seem convinced about my plan to recondition the battery. I still think its worth a shot if I can make this battery last a year or two longer. Wondering if I should hook up a trickle charger to the car when the battery is disconnected.

Was his suggestion to give him ~$500 to install a new battery?

I left mine disconnected for quite a while. The car is fine. Certainly don't run the recondition mode with disconnecting - likely it would be fine but better safe than sorry.

If it all bothers you buy a new battery and DCAN cable. Registration is super simple using Tool32 (IIRC).

I've had a battery tender on my bike for the last 6+ years and my battery just finally died. That's a long time to keep a cycle battery alive. I keep it plugged in 24/7 when not riding and never had an issue.

Originally Posted by 3284me

I've had a battery tender on my bike for the last 6+ years and my battery just finally died. That's a long time to keep a cycle battery alive. I keep it plugged in 24/7 when not riding and never had an issue.

My 725cc V-Twin lawn tractor has a 12V motorcycle battery. It's seven years old this summer and finally died about three weeks ago failing to crank. After reconditioning with the CTEK it's started every time and it has been used a lot recently. It is used to move a small trailer once in a while and in the last two weeks the trailer has been used often. I never left it trickle charging when not in use, even while out of the country for a year.

Keeping the battery running a bit longer has to be a good thing for everyone but people who sell them. Years ago they were user serviceable and we topped up cells with distilled water + the DIY types could use sodium sulphate to desulphate the plates.

Lead lasts forever, sulphation and loss of liquid are the problems (AFAIK - not an expert, just know how to use Google). Aside: Today the spot price of lead is a little over one dollar per pound, likely ~40lbs of our 50lb lead acid batteries is lead. Plastic and distilled water cost next to nothing... so that $480 installed battery is likely under $45 in materials. Only a 10x mark up by the time we get it

Update: The lawn tractor battery died again four weeks after reconditioning. I am beginning to doubt clams about reconditioning.

Thanks for the info. I'm still under the 4/50k so I'll see what BMW does next week. My mechanic is honest, but not cheap. He takes more time to explain stuff to me than my SA at the dealer.

If not, I think I'll try to recondition it. I have a dcan cable so all is well.

Originally Posted by unrealii

Thanks for the info. I'm still under the 4/50k so I'll see what BMW does next week.

If not, I think I'll try to recondition it. I have a dcan cable so all is well.

Me too. Went is several times between 10K and 11K miles with low battery light/ rough running issues. Dealer said the battery was fine. Problems persisted until I change the battery out.

I've been reading a lot of posts about this and came across this. I dont think it has been mentioned before. If anyone with TIS access wants to reconfirm, that would be great:

Originally Posted by tampamark

The TIS manual specifically says that charging of the battery should occur from the "external start-support point". It goes on to say "only then can the energy being fed into the vehicle be registered". If you have the TIS it is under REPAIR INSTRUCTIONS/61 GENERAL ELECTRICAL SYSTEM/21 BATTERY/VAPOUR SEPARATOR. Once in the page DISCONNECTING AND RECONNECTING NEGATIVE BATTERY LEAD. Then the sub link in the instructions listed as POWER SUPPLY.

Sounds like it is supposed to flow through the IBS. Anyway, just more information to digest.

http://www.bimmerfest.com/forums/sho...78&postcount=9

Battery tender works fine with my E60 through the underhood connections. However, a buddy came over for some coding on his 2006 330i E90. We had the key in position 2 and had the tender connected under the hood. After about an hour we were finished and he needed a jump.
He just wanted a jump so he could go home, meanwhile I'm stumped to the point that I could barely help him. I'm still trying to figure out what was going on. So I vote CTEK.

I received my ctek 7002 last week. Hooked it up Friday and it topped off the battery in a few hours. I clamped the ctek to the under hood posts. Saturday, I disconnected the neg terminal (I left the battery in the car and kept it well ventilated) and connected the ctek directly and ran the recondition. The recondition part took a about an hour (it does a full standard charge first before reconditioning). I let it sit for an hour or so without the charger then reconnected the terminal.

While the battery was disconnected, I mounted the permanent plug on the terminals under the hood. The proximity to the coolant expansion tank and all the heat generated has led me to consider putting a wire loom over the wires. I have a bunch of loom at my folk's house, so I'll be doing that within the next few weeks.

Back to the ctek. Sleep voltage was 12.37-12.41v prior to reconditioning/charging. One day after reconditioning it is 12.53v. This has resolved two issues - 1) bluetooth remains on if on an active phone call when car is turned off, 2) Comfort access for convertible top works in the morning

Few other things. When reconnecting the battery, I had to reset my clock. There was an idrive warning for that. I checked for codes using bmwlogger & usb dkan and it found none. I swung by my mechanic and his autologic tool detected a battery disconnected code (I dont know the number) and cleared it.

Any thoughts on if this is an acceptable battery voltage? I'd like stretch the life of this battery out as much as possible.

Originally Posted by unrealii

Any thoughts on if this is an acceptable battery voltage? I'd like stretch the life of this battery out as much as possible.

Right now you might just be seeing the effects of a recently charged battery.

Give it two weeks with no CTEK charging. Leave the car with engine off + radio on in your garage and see if the low battery light appears. IMO this is as good a test as any. Please report back so we have another data point.

Yeah, I'll keep an eye on it.

I took it to the dealer. Dealer said battery was ok. They ran a mid tronics test while doing the battery cable recall and that passed as well. Bluetooth decided not to stay on yesterday when I tested it after shutting the car off.

I'll take some more volt readings in the morning and see. I might just bite the bullet and replace the battery if its still bad in a few weeks. I have different battles with the dealer to fight which are worth more time than this.

Originally Posted by unrealii

Yeah, I'll keep an eye on it.

I took it to the dealer. Dealer said battery was ok. They ran a mid tronics test while doing the battery cable recall and that passed as well. Bluetooth decided not to stay on yesterday when I tested it after shutting the car off.

I'll take some more volt readings in the morning and see. I might just bite the bullet and replace the battery if its still bad in a few weeks. I have different battles with the dealer to fight which are worth more time than this.

Again I am repeating info but my brand new battery took over a week to behave well. My lawn tractor has run fine for almost two months since reconditioning its dead (motorycyle) battery + my old reconditioned BMW battery holds a decent amount of amp hours. It'd be interesting for someone to test Ah on a brand new OEM battery. Reading a book on Electronic components last week led me to believe manufactures may quote theoretical Ah which can be almost double actual Ah. i.e. my reconditioned battery's capacity may not be too far off a brand new one.