Ohmmu Na-Ion: DO NOT BUY

[fhteagle]

After only 66 days in service, my Ohmmu H3 sized sodium ion (specifically listed on their website for use in the F150L) battery is completely defective. No exterior signs of damage, overheat, fire, etc., and I DID do the 12V BMS reset the moment it was installed. It just will no longer take a charge, at all. I put it on a verified working 12V / 3A battery charger in AGM mode for ~15 hours. I still only have 6.7V across the terminals.

I have put in for a refund from the company. We'll see what they say, but if it is anything other than yep here is your money back, this becomes a credit card dispute.

So glad I kept my old worn OEM H3, so I could at least swap that back in until I can get something else.

You have been warned.

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[Maquis]

Open it up and you’ll see the junk components these things are made of.

 

[rockfish]

That sucks about the battery. I am just curious what prompted you to go with that type of battery instead of the AGM ? I was under the impression that the charging for a lithium or sodium type battery requires some change to the charging system... i could be wrong tho.

 

[The Weatherman]

That sucks about the battery. I am just curious what prompted you to go with that type of battery instead of the AGM ? I was under the impression that the charging for a lithium or sodium type battery requires some change to the charging system... i could be wrong tho.

OHMMU uses electronics on their Sodium and LI-ion to emulate a standard lead acid battery. In other words it has a BMS that looks a regular battery, but charges the battery appropriately.

You may say how does that guy know anything about these batteries?

The answer is he replaced his OEM with the LI-ion version a month or so ago.

 

[fhteagle]

I am just curious what prompted you to go with that type of battery instead of the AGM

1. Lead acid is an ancient, junky chemistry, and the sooner we quit using it, the better.
2. Even "premium" AGMs die in 3-4 years up here in the crazy daily/seasonal temp swings.
3. I thought Na-ion would be more durable than lead acid
4. I thought the vendor had fixed their issues after @Aminorjourney 's misadventures, but I guess not. We'll see if that was a "YouTuber got special treatment" case or not.

 

[Aminorjourney]

They'd offered to look at ours, but I don't think we ever got to an agreement on sending it back - it's still here for sure!

For the record, we try REALLY hard to not get any special treatment, and call it out if it happens!

 

[21st Century Truck]

Hmmm... as posted by me previously, I (so far) have had great service from the OHMMU battery, in pretty harsh Canadian Maritime weather and Newfoundland Winter weather.

My OEM battery was bulging, so I had to get "something" before the Canadian trip.

I hope that either Your case is an outlier, or that my case is and will continue to be an outlier case of unusual quality . And of course I'm sorry about Your failed OHMMU battery.

 

[garsh]

OHMMU uses electronics on their Sodium and LI-ion to emulate a standard lead acid battery. In other words it has a BMS that looks a regular battery, but charges the battery appropriately.

That is the hope, but the implementation cuts a lot of corners in that "emulation", and that can cause issues.

In this video, Ingineerix talks about 12v batteries for Teslas in general. But in the middle, he includes a teardown of an Ohmmu Lithium Ion replacement battery, explaining how it works, why people have so many problems with them, how it can actually damage a Tesla's PCS, and recommends avoiding them.

I think we'll eventually see more EVs switch to 16v (or hopefully, 48v) Lithium-Ion batteries for the low-voltage circuits in place of 12v systems. But until that happens, I'd stay away from trying to use these kinds of aftermarket replacements and just stick with the type of battery the vehicle was designed for.

 

[Mike G]

That is the hope, but the implementation cuts a lot of corners in that "emulation", and that can cause issues.

In this video, Ingineerix talks about 12v batteries for Teslas in general. But in the middle, he includes a teardown of an Ohmmu Lithium Ion replacement battery, explaining how it works, why people have so many problems with them, how it can actually damage a Tesla's PCS, and recommends avoiding them.

I think we'll eventually see more EVs switch to 16v (or hopefully, 48v) Lithium-Ion batteries for the low-voltage circuits in place of 12v systems. But until that happens, I'd stay away from trying to use these kinds of aftermarket replacements and just stick with the type of battery the vehicle was designed for.

I have avoided the temptation to 'upgrade' to the Diehard H3, which supposedly has a slightly greater Ah rating, simply because the BMS settings in the truck would likely routinely undercharge it. There are FORScan settings available for those who wish to 'tweak' their charging threshold etc. in the hope that somehow that would help, but I've found that simply doing a BMS learned values reset every six months and then going for a drive of an hour or more seems to do the trick. I'm still on my original battery after 3.6 years (1342 days since build date) and it's showing 100% SOC and no SOH warnings yet.

I also have connected up a trickle charger pigtail to the positive terminal of the battery and the chassis ground, and I did use that to keep the battery charged for a two-week period while I was on a trip once. But I only did that once and haven't bothered to do it since.

On a somewhat related 'getting locked out' topic.....everybody knows you can use PAAK (if you have that option) to unlock and drive your truck. If you don't also carry a fob with the backup key blade and the 12V battery dies, you might find it difficult to get back in to the truck. Another reason to either carry a fob, or stash a spare key blade somewhere inside the truck, is you might find you have no way to get to your spare tire in the event you have a flat and need to change it. The old "Hide-a-Key" thing is a good idea.

 

[TaxmanHog]

I have avoided the temptation to 'upgrade' to the Diehard H3, which supposedly has a slightly greater Ah rating, simply because the BMS settings in the truck would likely routinely undercharge it. There are FORScan settings available for those who wish to 'tweak' their charging threshold etc. in the hope that somehow that would help, but I've found that simply doing a BMS learned values reset every six months and then going for a drive of an hour or more seems to do the trick. I'm still on my original battery after 3.6 years (1342 days since build date) and it's showing 100% SOC and no SOH warnings yet.

I'll be at the six month mark early February, I'll pay attention to my Diehard H3 to see if it's under performing, if so I'll give the BMS reset a shot, so far so good though 5+ months in.

 

[Ekiehn]

I had a warranty OEM replacement AGM earlier last year. Months later I started seeing similar 12v symptoms, checked with car scanner and determined that I was stressing the battery. I drive maybe 10 min to work in the morning and about 15 min in the evening due to traffic. Some days of the week I may go to meetings within typically 5-10 min. Weekends can be longer drives or no drives at all. Not a good scenario for AGM. So I switched to the OHMMU Li-ion and it's been about 3 months with no detection of the old 12v issues... my basis for doing the switch was that Li-ion can handle the deeper discharge than AGM. Right now "mistress" is at the dealer awaiting a replacement LED control module for the left high beam flicker reported elseware on the forum. It will be about a week sitting there. I would have worried with the AGM given my driving situation before dropping it off. Right now no worries...

 

[chl]

1. Lead acid is an ancient, junky chemistry, and the sooner we quit using it, the better.
2. Even "premium" AGMs die in 3-4 years up here in the crazy daily/seasonal temp swings.
3. I thought Na-ion would be more durable than lead acid
4. I thought the vendor had fixed their issues after @Aminorjourney 's misadventures, but I guess not. We'll see if that was a "YouTuber got special treatment" case or not.

I have kept my AGM battery in my Nissan Leaf alive since 2012 by keeping it on a battery maintainer when ever not in use.

It is not magic, just chemisty - lead acid batteries prefer to be fully charged as often and as long as possible - keeps them healthy.

Deep discharging and high charge currents are what slowly kill lead-acid batteries.

Deep discharge = sulfation on the plates
High charging current = heat and hydrogen gas

So give them TLC and they'll live happily ever after.

 

[mr.Magoo]

I have avoided the temptation to 'upgrade' to the Diehard H3, which supposedly has a slightly greater Ah rating, simply because the BMS settings in the truck would likely routinely undercharge it.

I'll be at the six month mark early February, I'll pay attention to my Diehard H3 to see if it's under performing, if so I'll give the BMS reset a shot, so far so good though 5+ months in.

I've had mine for 674 days (1yr and 10 months) and so far I have not seen anything that would indicate that the battery is being undercharged and I haven't been kind to mine, (one complete discharge down to 0% SoC by mistake and a few down to 20-40% on purpose).

 

[fhteagle]

Ohmmu replied. They are denying the return for refund, claiming the battery was damaged due to overdischarge. This is BS for at least two reasons:

1. This battery is advertised as fit to be used with the F150 Lightning, so therefore it should be resilient against normal use / discharge by that platform.
2. If these were authentic sodium ion batteries, they should be able to be discharged safely to 0V and then brought back into service.

So, Ohmmu is fraudulent and not fit for the advertised purpose in multiple ways. Credit card dispute / chargeback in progress.

 

[fhteagle]

They'd offered to look at ours, but I don't think we ever got to an agreement on sending it back - it's still here for sure!

That kind of adds to the "something is wrong here" if they did not want it back for a postmortem / failure analysis.

For the record, we try REALLY hard to not get any special treatment, and call it out if it happens!

Sure, that was not a jab at you all. Just wondering if you and/or your company name might be recognizable to vendors in the space. Whether you ask for it or not, said vendors have a vested interest in making sure those with a following have a good experience.

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