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Has anyone actually tried the ACDelco LN1AGM battery? Looks to be exact size, vents on both ends with a plug for the unused port.
I would not use an AGM battery unless there is a need to be spill-proof. They are not as durable, particularity against overcharging and the cells can't be equalized which can lead to premature failure of some cells - which you definitely don't want to happen on the ED as this can trigger a traction pack bricking.

I recently bought an Advance Auto "Die Hard Gold" group H5. It is slightly longer than the OEM battery but fit in the battery well with still some room to spare without problems. A tab on the hold-down bracket had to be bent upward for it to work with this battery - that was the only modification. (See the link below - not "down for maintenance")

 

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I would have no qualms using an AGM battery personally. But I have not tried one in the smart.

Some digging has revealed potential size matches:

LN1
H4
140R
L1 ? (? because I only saw one source mention it batterysource.com)

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I would have no qualms using an AGM battery personally. But I have not tried one in the smart.

Some digging has revealed potential size matches:

LN1
H4
140R
L1 ? (? because I only saw one source mention it batterysource.com)

Sent from my moto g(7) power using Tapatalk
i have a lot of (bad) experience with AGM batteries in a traction application (an early electric motor scooter) and they certainly are not at all good for deep cycle applications, becasue of the inability to balance-equalization charge them by periodically deliberately overcharging them. Overcharging cannot be done on AGM cells since they have no excess electrolyte to lose and no ability to replace lost electrolite. One or two cells inevitably become out of balance and the rest of the cells see repeated overcharging and the battery is ruined.

While the battery should never get deep-cycled on an ED, I simply see no advantage to an AGM, only potential disadvantages. The OEM is a conventional flooded battery with an old-fashioned "Delco eye" to indicate low electrolyte level.

As I wrote, group H5 also fits.
 

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(I don't mean to be argumentative just looking for your experience). AGM is claimed to last longer than the regular flooded type in similar application. Is your experience opposite?

They claim it charges back up quicker/less internal resistance. Is this not true? (I agree likely not (as) beneficial in an ED as it is not drained cranking a starter).

I've also read that they are more sensitive to overcharging. Yes that makes perfect sense there is not much electrolyte buffer to boil off in the first place. Interestingly they all seem to develop concave/uneven casings over their lifespans. Likely due to outgassing and since it is a one way valve the vacuum created after. With that concern one would assume the charging system needs to be set at a lower voltage relative to flooded. I was surprised when I read my NOCO G7200 manual to find that charging voltage is actually set higher for AGM. (I am attaching a screenshot of the online owners manual showing this).

2nd and 3rd Gen Prii have the 12 V battery in the trunk. AGM is prescribed as this is part of the cabin. Safety aspect as acid can't leak out and cause a hazard. I've read about instances where the battery was being cooked by the ED charging system and the smart interior smelled like rotten eggs. The smell is actually H2S, same stuff they use to tint gasoline in PPM to make it smell and is actually a toxic gas. An accident may not ever reach the 12 V in a smart but...






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In my experience, with using AGM's in an 48 volt upgraded to 60 volt electric motor scooter where spill proofness was required, the life of the batteries was very short - less than a hundred cycles sometimes. Invariably a cell in a battery would go bad - probably from overcharge or over discharge, and cause the whole battery to go bad. You certainly don't ever see AGM's in golf carts, forklifts, underground mining equipment, trolling motor batteries, sailboat power systems and other applications subject to deep discharge that still use LA batteries.

In the case of the scooter, I replaced the LA batteries with 20 LiFePO4 cells and a balancing system for a dramatic improvment in battery life, range and weight.

My general feeling is that you have to be sceptical of information provided by someone trying to sell you something.
 

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I gave up the idea of an AGM and bought an OEM battery. It was expensive ($200.25), but all in all I think it might have been the better choice. What a bear cat to change! Anyway, it's done so I feel better about the future of our little blue rocket. Thanks to all for your inputs.
 
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