Boulder GT3

I'm not going to be driving the SL55o for a few months. If I connect a battery tender to the starting battery will it charge the aux/trunk battery as well? Thanks

R230_Nicke

I dont think so.
I use two chargers when I winter store my baby now.
Last winter I only use one tickler to the front and and the rear was out when I started it up a few months later.

Nicke

Boulder GT3

Not what I wanted to hear but thanks for the answer. That's what I was afraid of. There is a relay of some sort that isolates the two even though some functions are on the same power bus.

Thanks

jj0822

I think I read somewhere that the starter (front) battery will eventually not draw any power and will stay charged for months. The rear battery supports the electronics and will only last a week or two. I always trickle charge the rear, but haven't needed to charge the front but it only sits for about a week or two max. The rear battery warning will come on if I don't charge it after about 5 days.

IngenereAMG

When my SL55 sits for more than 2 weeks the rear battery is the one that gets weak. I am still able to start the car, but there is the 'consumables off line" message. Within a few miles of driving it is fully charged.

jmf003

+1. I put the charger on the rear battery, not the front.

StephenK

Consumables Battery isn't that located in the trunk???

R230_Nicke

Yes..

TwinCam

The best way to keep your car charged while in storage is to use the CTEK Multi 3300 battery charger. This is the exact same unit sold by Mercedes, but MB parts charges a much higher price than other CTEK retailers. The CTEK is a trickle charger that electronically maintains the charge in the battery. I hooked the device up to the trunk battery in my 2007 SL600 last year while I spent the winter in Florida, 4 months later when I got back to Chicago, my SL started right up and was fully charged. I purchased my charger on line from the Home Depot who had the best price, however there are other retailers listed on line. Other friends with SL's report great results with this charger. Just make sure you attach it to the trunk battery as that also keeps the under hood battery fully charged. TwinCam

SPIKES

i believe by charging the rear battery it keeps the front battery charged up as well.

Boulder GT3

Right you are. I hooked up a Battery Tender to the rear battery and checked voltages 2 days later. Both full up.

ohlord

charged before storage,then hook up
http://www.harborfreight.com/cpi/cta...emnumber=42292

it works great.

khaz3al

what if i got the battery sign, and the consumables offline sign when i drive the car, not even off for 12 hrs or so... maybe the alternator?
what else could be the problem, now i turn on the car and it turns off by itself..
and i get the STOP turn off car sign.
anybody else has the same problem?

khaz3al

rodin66

Can you connect this battery tender to the Convenience battery while the Conv Battery is still connected to the car ? -- Or does it have to be disconnected

While away over Xmas I connected my Porsche Battery Maintainer ( via the Cigar Lighter ) and I don't think this fed into the convenience battery --- Car still starts and runs but " Convenience Functions Temporary unavailable" -- I've tried driving the car ( albeit only 20 miles ) and Convenience Functions yet to return

My Range Rover was parked ( outside) at Newark with a Solar Powered Maintainer plugged into cigar lighter and it started up first time

SPIKES

i have the same porsche charger from my 911 and tried it on the sl.
i found that the light under the mirror would come on while it was connected. i dont think the sl electronics like it.

rodin66

Yes I think you're right

brtuffli

concerning the above posts, an engineer from deltran (the battery tender manufacturer) opines that if you try to charge both batteries by connecting to the rear one only, you run the risk of frying the front battery if the rear one fails. he says that the battery tender will read the bad rear battery as needing more charging and the resulting increased charging will cause the front battery to be overcharged. i guess if you're convinced that both batteries are in good condition, this would not be a worry.

for what it's worth.

Lee Wireless

Read this for the truth instead of a bunch of Internet opinions that may or may not be correct. Do your homework. http://batterytender.com/faqs.php?os...4a358a7302eb85

Lee Wireless

See attachments

funnyguy1

CTEK Charger, they run about $69 bucks. Hook it to the trunk battery and store it.

mlandis

I don't know if the charger cable or port location will allow it, but did either of you try connecting to the power outlet in the trunk instead of the cigar lighter?

DeLorean00

I have been using those for years on my Ferrari and DeLorean. Works great!! Good ol' Harbor Freight.

mlandis

For those of us who don't have electrical outlets in garages (the joys of living in an apartment) does anyone have any product recommendations? Are solar chargers really that useful? Etc. Etc.

Thanks in advance,

Michael

Rook3300

I'm sure you could go over to Lowe's or Home Depot and pay one of those guys standing out front to ride a bike for 9 hours and charge it up.

Rook

Lee Wireless

This is a good unit. I have them installed on over 100 backup generators to keep the start batteries fully charged. It has a regulator to keep from over charging. Good Luck. http://www.batterystuff.com/solar-chargers/SP-2.html