Stan Schweitzer
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From: Gippsland, Australia
GLE 450+ SLK350
Stan Schweitzer
New GLE 450. Doesn't get a lot of use so would like to trickle charger but dealer advises that because there are two different types of battery i.e. 12V Lead Acid AGM and a 48V Lithium I cannot use a standard charger.
Any suggestions?
Any suggestions?
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Joined: Jul 2020
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From: Southeast US
2025 CLE AMG 53
Did the dealer say why? I have an Acura RLX Sport Hybrid that also has dual electrical systems and I am using a Battery Minder as recommended by the dealership. I've never had any problems.
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Joined: Apr 2014
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From: Gippsland, Australia
GLE 450+ SLK350
Thanks. These batteries have entirely different charging requirements. The charger needs to have dual charging capabilities or you may cook one or both batteries. These are rare. I have tracked down one badged by Mercedes that states that it is suitable for both battery types. It appears to be similar to CTek chargers but a direct enquiry to them revealed that they do not make such a unit. I couldn't find one from another manufacturer. Mercedes recommend their charger for the GLE 450. I have taken their advice. Price about US$195.
Last edited by stan911; Aug 13, 2020 at 09:34 AM.
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From: Pennsylvania
2024 GLE 450 4matic
The 12 volt battery is an AGM and will sulfate (go bad) with prolonged discharge, It will benefit from a battery tender.
The 48 volt battery is a Lithium Polymer variant and is not subject to degradation from prolonged storage.
The 48 volt battery is a Lithium Polymer variant and is not subject to degradation from prolonged storage.
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Joined: Apr 2014
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From: Gippsland, Australia
GLE 450+ SLK350
Agreed...re degradation of AGM battery. Claims of doubling of battery life with maintenance of charge. The AGM in my ML 350 lasted over 9 years with careful charging. Information regarding the exact technology of the independent charging of the two batteries in the GLE 450 is not readily available at present. I was told by dealer that both batteries are directly charged from the posts under the hood and that is the reason for the dual lead acid/lithium capability of the charger. These are massive batteries and given the intermittent use I think it is wise to keep them on a tender, but lithium batteries are very sensitive to overcharging and overheating. The issue is not loss of charge but very real hazard of overcharging it. This is less of an issue with lead acid batteries, hence the need for different charging parameters.
Last edited by stan911; Aug 13, 2020 at 09:35 AM.
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2022 Mercedes EQS 580
Thanks. These batteries have entirely different charging requirements. The charger needs to have dual charging capabilities or you may cook one or both batteries. These are rare. I have tracked down one badged by Mercedes that states that it is suitable for both battery types. It appears to be similar to CTek chargers but a direct enquiry to them revealed that they do not make such a unit. I couldn't find one from another manufacturer. Mercedes recommend their charger for the GLE 450. I have taken their advice. Price about US$195.
The risk you describe is only an issue if you connected an AGM charger to a lithium battery. If you had just a CTEK AGM charger for the 12v and a CTEK Lithium charger for the Lithium, that would be fine too.
Last edited by stealth.pilot; Aug 13, 2020 at 06:10 PM.
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Thread Starter
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Joined: Apr 2014
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From: Gippsland, Australia
GLE 450+ SLK350
I am informed that it is...dunno if that's correct. I think the two batteries are connected by a DC/DC converter that allows this. 48V on the charging posts would represent a shock hazard. As to jump starting, I think 48V would be needed by the starter/alternator. Any one knows better please enlighten us. Lithium batteries do not appreciate continuous maintenance trickle charge like lead acid batteries hence need for special charger. A standard charger would probably be OK as long as it is disconnected as soon as full charge is indicated. I do not wish to risk a fried battery(s) so I have gone with Mercedes' recommendation. As a side note, US owners manual states 14.8V maximum charge voltage versus Australian manual's 14.4V. Is this significant? Comments?
Last edited by stan911; Aug 14, 2020 at 01:29 AM.
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From: Pennsylvania
2024 GLE 450 4matic
14.X volts is ok for the bulk and absorb stage of an AGM battery but you'll kill it shortly if left at that voltage. Unless you're planning on using a quality automatic battery maintainer, you're better of using nothing.
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Joined: Aug 2019
Posts: 81
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From: Outside St Louis, MO
'20 GLE 450, Silverado 3500
Did anyone determine which CTek charger is the same as the MB charger for the GLE450? It is my understanding that CTek does in fact make the MB charger. Has anyone done a spec comparison between the MB charger and the various CTek chargers? Can someone give the part number for the MB recommended charger?
Last edited by Brer Rabbit; Oct 22, 2020 at 01:54 PM.
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From: Colorado
'21 AMG53 wDPP & ARC, 19 GLC300 - Former-03 C240,2 ML BlueTecs,20 GLE450 E-ABC,15 Cayenne D,17 Macan
Did anyone determine which CTek charger is the same as the MB charger for the GLE450? It is my understanding that CTek does in fact make the MB charger. Has anyone done a spec comparison between the MB charger and the various CTek chargers? Can someone give the part number for the MB recommended charger?
I use a Battery Tender, but only when I plan on not using the car for more than a month.
The 12V battery is VRLA, or more correctly a Valve Regulated Lead Acid battery. Meaning any gassing is contained by a valve that holds it in unless there are extreme conditions. There are a few types of VRLA's, including AGM and Gel. Self-discharge is lower than a straight Lead Acid, and less than the Lithium.
I thought there was a 12V tap from the 48v generator/charger, instead of a DC-DC 48v-12v converter. And that the systems were completely isolated. Anybody know for sure?
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Joined: Aug 2019
Posts: 81
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From: Outside St Louis, MO
'20 GLE 450, Silverado 3500
Thank you for the replies.
I sent an email to CTEK asking them what CTEK charger was compatible with the MB GLE450 mild hybrid. Their replay was:
" There are many charger options for you including the Mercedes-Benz branded charger that is manufactured by CTEK. This charger is available through your local Mercedes dealership. If you are interested in a CTEK branded charger, our MXS 5.0 (40-206) is designed for lead-acid and AGM batteries up to 160Ah. If your vehicle battery meets this criteria the MXS 5.0 will also work well."
From their response, I conclude
1) CTEK makes the MB charger
2) Sounds like the MXS 5.0 might be the right charger for the GLE.
The way I understand the charging process, from reading the owner's manual, the 48V battery(s) is charged from the 12V battery. Is that your understanding?
Owner's Manual pg 584 (at least the version I have):
This sounds like the 48V system battery is isolated from the charger via the 12V battery and the voltage converter. I think this would eliminate the requirement for a lithium compatible charger, but maybe not. As long as the 12V battery is charged correctly, I think the 48V battery will be charged. I do not know that for sure but sounds like it.
mikapen, which MB and CTEK chargers where you comparing? CTEK has a number of chargers and MB has at least a 5 amp and a 25 amp charger. GLS 450 Accessories
The manual talks about using a
. I would love to see that list.
They sure look the same. I checked the spec's on both about six or seven years ago and they were identical (CTek & M-B).
I use a Battery Tender, but only when I plan on not using the car for more than a month.
The 12V battery is VRLA, or more correctly a Valve Regulated Lead Acid battery. Meaning any gassing is contained by a valve that holds it in unless there are extreme conditions. There are a few types of VRLA's, including AGM and Gel. Self-discharge is lower than a straight Lead Acid, and less than the Lithium.
I thought there was a 12V tap from the 48v generator/charger, instead of a DC-DC 48v-12v converter. And that the systems were completely isolated. Anybody know for sure?
I use a Battery Tender, but only when I plan on not using the car for more than a month.
The 12V battery is VRLA, or more correctly a Valve Regulated Lead Acid battery. Meaning any gassing is contained by a valve that holds it in unless there are extreme conditions. There are a few types of VRLA's, including AGM and Gel. Self-discharge is lower than a straight Lead Acid, and less than the Lithium.
I thought there was a 12V tap from the 48v generator/charger, instead of a DC-DC 48v-12v converter. And that the systems were completely isolated. Anybody know for sure?
" There are many charger options for you including the Mercedes-Benz branded charger that is manufactured by CTEK. This charger is available through your local Mercedes dealership. If you are interested in a CTEK branded charger, our MXS 5.0 (40-206) is designed for lead-acid and AGM batteries up to 160Ah. If your vehicle battery meets this criteria the MXS 5.0 will also work well."
From their response, I conclude
1) CTEK makes the MB charger
2) Sounds like the MXS 5.0 might be the right charger for the GLE.
The way I understand the charging process, from reading the owner's manual, the 48V battery(s) is charged from the 12V battery. Is that your understanding?
Owner's Manual pg 584 (at least the version I have):
The charge level of the 48 V battery is too low. You can no longer start the engine.
# Switch off electrical consumers that are not required.
# Connect a suitable charger approved for Mercedes-Benz with sufficient charge output to the jump-start connection point of the 12 V battery (/ page 481).
The 48 V battery is charged via the voltage converter in the vehicle.
# Switch off electrical consumers that are not required.
# Connect a suitable charger approved for Mercedes-Benz with sufficient charge output to the jump-start connection point of the 12 V battery (/ page 481).
The 48 V battery is charged via the voltage converter in the vehicle.
mikapen, which MB and CTEK chargers where you comparing? CTEK has a number of chargers and MB has at least a 5 amp and a 25 amp charger. GLS 450 Accessories
The manual talks about using a
charger approved for Mercedes-Benz
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From: Colorado
'21 AMG53 wDPP & ARC, 19 GLC300 - Former-03 C240,2 ML BlueTecs,20 GLE450 E-ABC,15 Cayenne D,17 Macan
.........
mikapen, which MB and CTEK chargers where you comparing? CTEK has a number of chargers and MB has at least a 5 amp and a 25 amp charger. GLS 450 Accessories
The manual talks about using a . I would love to see that list.
mikapen, which MB and CTEK chargers where you comparing? CTEK has a number of chargers and MB has at least a 5 amp and a 25 amp charger. GLS 450 Accessories
The manual talks about using a . I would love to see that list.
That 25A charger is a lot more than anybody would need to maintain a battery, even one that was pretty low on charge. I use 1.25A Battery Tenders on most of my equipment and they are plenty adequate - four stage, too. So that 5A CTEK should be more than enough for most needs.
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Joined: Apr 2014
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From: Gippsland, Australia
GLE 450+ SLK350
I use a cheap 8 amp charger that is superior in use to CTek and 20% of price (~US$20). It displays temperature, voltage, charging amps and is 12V/24V switchable between car, motorcycle and AGM?Gel. Switches off when fully charged and maintains level at about 13.6V. Hard not to like.
Search Banggood (excellent to deal with)
Search Banggood (excellent to deal with)
Enusic™ 12/24V 8A Red Touch Screen Pulse Repair LCD Battery Charger For Car Motorcycle Lead Acid Battery Agm Gel Wet - US Plug
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From: Colorado
'21 AMG53 wDPP & ARC, 19 GLC300 - Former-03 C240,2 ML BlueTecs,20 GLE450 E-ABC,15 Cayenne D,17 Macan
.....
The way I understand the charging process, from reading the owner's manual, the 48V battery(s) is charged from the 12V battery. Is that your understanding?
Owner's Manual pg 584 (at least the version I have):
The way I understand the charging process, from reading the owner's manual, the 48V battery(s) is charged from the 12V battery. Is that your understanding?
Owner's Manual pg 584 (at least the version I have):
"The charge level of the 48 V battery is too low. You can no longer start the engine.
# Switch off electrical consumers that are not required.
# Connect a suitable charger approved for Mercedes-Benz with sufficient charge output to the jump-start connection point of the 12 V battery (/ page 481).
The 48 V battery is charged via the voltage converter in the vehicle."
This sounds like the 48V system battery is isolated from the charger via the 12V battery and the voltage converter. I think this would eliminate the requirement for a lithium compatible charger, but maybe not. As long as the 12V battery is charged correctly, I think the 48V battery will be charged. I do not know that for sure but sounds like it.# Switch off electrical consumers that are not required.
# Connect a suitable charger approved for Mercedes-Benz with sufficient charge output to the jump-start connection point of the 12 V battery (/ page 481).
The 48 V battery is charged via the voltage converter in the vehicle."
But it doesn't make sense for that to be the primary circuit to charge the 48v battery - inefficient energy loss through the converter (conversion losses), plus wire size would have to be increased.
The primary charging of the 48v system is directly from the ISG (Inline Starter Generator)
I have another quote from Daimler, which states
"The power for the 48 volt network is generated by the ISG. Located between the engine and the transmission, this electrical machine combines the functions of a starter and alternator. The conventional 12 volt network is likewise supplied from the new network using a 48 volt/12 volt DC/DC converter." (Source- https://media.daimler.com/marsMediaS...l?oid=22934110 )
So it looks like there is a 48v/12v converter (should be more efficient than 12v/48v) to keep the 12v system charged.That makes sense, since the high load stuff stays 48v, with smaller wires and connectors, and the 12v "legacy" equipment doesn't need as much current.
It seems that there are two DC/DC converters are aboard - one 12/48 and one 48/12.
MBWorld Fanatic!
Joined: Oct 2009
Posts: 7,057
Likes: 2,214
From: Colorado
'21 AMG53 wDPP & ARC, 19 GLC300 - Former-03 C240,2 ML BlueTecs,20 GLE450 E-ABC,15 Cayenne D,17 Macan
I use a cheap 8 amp charger that is superior in use to CTek and 20% of price (~US$20). It displays temperature, voltage, charging amps and is 12V/24V switchable between car, motorcycle and AGM?Gel. Switches off when fully charged and maintains level at about 13.6V. Hard not to like.
Search Banggood (excellent to deal with)
Search Banggood (excellent to deal with)
Enusic™ 12/24V 8A Red Touch Screen Pulse Repair LCD Battery Charger For Car Motorcycle Lead Acid Battery Agm Gel Wet - US Plug
Member
Joined: Aug 2019
Posts: 81
Likes: 22
From: Outside St Louis, MO
'20 GLE 450, Silverado 3500
That is likely true, but only in the case of depleted batteries. It looks like there is, in fact, a 12vDC/48vDC converter so you can get juice into the 48v battery without a 48v charger.
But it doesn't make sense for that to be the primary circuit to charge the 48v battery - inefficient energy loss through the converter (conversion losses), plus wire size would have to be increased.
The primary charging of the 48v system is directly from the ISG (Inline Starter Generator)
I have another quote from Daimler, which states
That makes sense, since the high load stuff stays 48v, with smaller wires and connectors, and the 12v "legacy" equipment doesn't need as much current.
It seems that there are two DC/DC converters are aboard - one 12/48 and one 48/12.
But it doesn't make sense for that to be the primary circuit to charge the 48v battery - inefficient energy loss through the converter (conversion losses), plus wire size would have to be increased.
The primary charging of the 48v system is directly from the ISG (Inline Starter Generator)
I have another quote from Daimler, which states
"The power for the 48 volt network is generated by the ISG. Located between the engine and the transmission, this electrical machine combines the functions of a starter and alternator. The conventional 12 volt network is likewise supplied from the new network using a 48 volt/12 volt DC/DC converter." (Source- https://media.daimler.com/marsMediaS...l?oid=22934110 )
So it looks like there is a 48v/12v converter (should be more efficient than 12v/48v) to keep the 12v system charged.That makes sense, since the high load stuff stays 48v, with smaller wires and connectors, and the 12v "legacy" equipment doesn't need as much current.
It seems that there are two DC/DC converters are aboard - one 12/48 and one 48/12.
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Joined: Apr 2014
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From: Gippsland, Australia
GLE 450+ SLK350
Yes...totally mystifying. Obviously there is no direct connection between the 48V Li-ion and the engine bay terminals. The 12V must be used to charge it if required, as there is no direct way to access or charge it. There is no separate alternator, the ISG motor is the only charge source so current flows from 48V to 12V via DC/DC converter for charge. The 48V system is used to start the engine so it must retain enough charge to allow this in normal use. How a 12V jump starter on the engine terminals works is uncertain, but there must be a reverse 12V to 48V pathway. When driving, the engine display shows ~14.6V which must be Li-ion system voltage, but at rest ~12.6V which must be AGM voltage.
The Enusic charger is very similar in function to CTek and switches off when charge is achieved. I have found them very solid performers. The only disadvantage I can see is the lack of the CTek's quick release clips and maybe less moisture resistant.
The Enusic charger is very similar in function to CTek and switches off when charge is achieved. I have found them very solid performers. The only disadvantage I can see is the lack of the CTek's quick release clips and maybe less moisture resistant.
