Opening an EGO 7.5AH battery to test cells

[@jimmydavis7990]

Hello… I had same issue you had… took apart and put back together and it now works… EGO Rep. said I need to replace the battery… saved a lot of $$$.

[@summetj]

Only thing I can think of to explain it is that a wire with a bad connection got bent the right way to "fix" it......because I didn't actually do anything other than open it up and look at it.

[@BGittins1]

Hi, there is a pattern that I am seeing with EGO batteries with high resistance developing across the connector plug connectors. Sometimes just bumping the battery will fix it. If you pull it apart and simply plug & unplug connectors you fix 'unexplained' faults as recorded on the BM system. Best to have a can of contact cleaner (eg CRC NF Contact Cleaner) at hand and give the connectos a spray whilst seperated. One other point, thre main personal danger of opening these batteries is arcing faults between the high energy cables. (Any any short can also kill the electronics) A heavy arcing fault could also lead to battery explosion or fire both of which could be quiet bad. However, your skin is fairly resistive to 60 Vdc and so it is virtually impossible to get an electric shock off these batteries so your gloves are not really required for electric shock protection. That said, in other circuits with large inductors, 60 Vdc could be 'enhanced' with inductive loads, but not in these batteries.

[@coppulor6500]

You seem to knowledgeable in this area. I have a question for you. Since the cells appear to be 18650 cells, how feasible is it to replace them yourself and how would one go about increasing the capacity? Would that simply be a matter of using higher capacity batteries? Is there a circuit board that would need rewiring in which case, never mind lol? Your thoughts would be appreciated :-)

[@honeyforce996]

Ty for the video, I think I fixed mine by reseating/cleaning the connection that is between the 2 halves of the cell packs Check out 13:30 of this video: "EGO 56V Gen1 5AH Blinking Orange Fix" by Thrifty Tool Shed My original complaint was that the mower would randomly cut out while mowing. I think the battery would flash orange, and the mower might have flashed yellow. You would have to wait 10-30 seconds, and then it would be able to be restarted/used as normal I did the Thrifty Tool Shed "fix" (basically pull the 2 halves apart, pull the connector or two out, reseat them). I then mowed my lawn. The mower did not die. It also seemed to automatically kick into a "turbo" mode when about to bog down. I don't recall it doing that before the fix. So maybe the turbo boost is related; like, it draws more power, which overloads some loose connection or something, and causes a safety fault. I don't know; I'm not even 100% sure it's fixed, but it's been through 3 charges since, and no cutouts yet. Previously I think it would cutout once every 1-2 mows.

[@philmccracken2012]

The screws on the outside of the case that you need to start to remove first to get inside the battery is "Torx #15" security bit. It's like a normal torx bit that has a hole in the middle. The actual screw that you need to remove has a little nipple dead center on the head of the screw. That is the "security" part. Once you removed all of the screws that are on the outside of the battery case there is a possibility if you're wanting to take apart the battery packs inside with the individual cells that you will need a "Torx #10"

[@briansbausch]

My mower had the same failure: full charge 7.5Ah flashes Red after 10 feet, not using self-propulsion. Watched videos, was leaning towards checking the 3 safety relays and for frayed wires @ pivot point, then I remembered hitting a stone with the blade and having to Dremel an edge on the resulting ding. Put this blade on a nail and discovered it was a couple degrees off level so unbalenced. A new mower blade fixed this problem, have had no problems for over a month mowing 2 lawns that total 1.5 acres.

[@grandpaworks8632]

according to ego tech support if the batteries do not have that extra shell around the cells then its a rebuild battery. ego tech told me that all they use in all their batteries and has not change their technique.

[@K03sport]

my 7.5 kept showing a overheat condition when just starting and I got the solid red light on the quick charger. it happened 10 days prior to the end of the 3yr warranty. EGO replaced it, so kudos to them....I haven't pulled it apart yet...prior to failure, my mower would cut out due to over-temp, even on 60* days

[@CaedenV]

Huh... Well... I'm stumped. My old battery appears to be perfectly fine. I was sure I had some bad Leakey cells because of some white stuff that showed up behind the holes of the covers, but nope, it's just the insulation they use. All the cells look great, and the voltages are right where I would expect... So... Vrm or connection issues?

[@Suzukii-DIY]

The tool to remove the screws is a T6 Security tamperproof torx bit. Your welcome

[@cuisinartOH1]

You're. You're welcome.

[@miken7275]

Very helpful, thanks. My battery is 2 years old and after 10 mins of running it will flash orange. It’s so confusing and curious if you have had to repair or test that issue yet.

[@summetj]

They come with a 3 year warranty (for the original purchaser) and that sounds like something ego would definitely repair under warranty.

[@miken7275]

@@summetjthanks will call the company.

[@TooncesLives]

Wondering if you're able to provide the order for the 12-pin connector on the 7.5 batteries? Was taking mine apart for a different reason and they pulled out with very little force (was quite surprised). Thanks!

[@summetj]

I'm afraid I do not have that pinout information.

[@TranTek]

when you took them apart you un tangle those wires i seen a few report that is how to fix most of Ego issue unless your cells go bad, those Samsung cells are pretty reliable

[@summetj]

It is certainly possible that one of the wires has a small break or intermittent fault within it and by rearranging them I touched the ends back together better.

[@TranTek]

@@summetj you don’t really need to wear those gloves lol i worked on many tools batteries they won’t shock you, just make sure you don’t short them up cuz they burn anything even those gloves

[@summetj]

@@TranTek well, since I had them, I figured better safe than sorry. In the US under 48 volts is the "low voltage" designation, but I do agree with you that the 56 volt battery is nowhere near as scary as the 400 volt Nissan leaf pack.

[@georgepelton5645]

@@summetj 60 V is the threshold generally used for lethal shock risk. Better safe than sorry.

[@Decscorpion]

Do you happen to have pics of the connectors on the “BMS” I’m trying to repair one that was found and curiosity is stringing of proper order for the wires and which one should be in which terminal of the plug. THANKYOU and great video! 5 7.5ah batteries !!!!! Yeeeshhhhhhh

[@summetj]

I'm afraid I do not, in the one I opened the BMS board was "potted" inside

[@Decscorpion]

@@summetj Thank you for your response!!!!! I was looking for the connectors that plugged into the bms.....the terminals pulled out of the white clips. I appreciate all of your help!

[@markbrown1609]

56 volts will wake you faster than a cup of coffee.

[@paradislarry]

I've read other comments where they just take the battery apart like you did, moved some wires out of "crunch positions" re-assembled & wallah !!! just like what happened to you.

[@Suzukii-DIY]

I can't believe that I just took my 7.5ah battery apart, put it back together, and now the dang thing is charging and running my mower with no problem. What it was doing was that it would charge up 75% and immediately jumped 100%. Then, when I go to put it on the mower or the blower, it would immediately flash red.

[@parkgee9848]

May I ask what is the part number of the Samsung li-ion battery? Is it INR18650-20R or INR18650-25R?

[@summetj]

The label on the cells only says "INR18650S-2500mAh 3.6 v 9.0 Wh UL1L031FQB 234642" so hopefully that helps

[@parkgee9848]

@@summetj Thanks. It is not meant to be used for power tools which require high drain current of at least 20 amperes (CDR continuous discharge rate). It has a max. CDR of 7.5 amperes. That is why these batteries die early. They should have last more than 10 years if they are the original Samsung INR18650-20R (discontinued).

[@victoryfirst2878]

How much did the battery pack cost you fella ??

[@summetj]

I don't remember exactly, but I usually buy a used mower and battery in the $200-$300 range.

[@toddk63]

Some wires came loose from the connector while taking apart. Its the upper right connector (low side?) 12 pins, but with only 10 wires. Here is what I know {Blk-Blk-Red-Grn-?-?-?-Wht-?-Grn-?-Blk}. I have three wires that pulled out. They are Blu,Red, and Yel. Can anyone help?

[@TooncesLives]

Wondering if you ever figured this out? I didn't see this post when I asked the same question a bit ago. Thanks for any info you can pass along!

[@toddk63]

@@TooncesLives No. I keep hoping

[@TooncesLives]

Order is: black, red, green, yellow, white, blue, empty, empty, green, red, black, black

[@toddk63]

So you matched what you knew from remaining wires with what I knew/ Brilliant!

[@NaughtyGoatFarm]

Test the cells by probing the balance cable plug.

[@arthurhudgens8213]

I fixed my ego mower by cleaning the carb on my old gas lawnmower it had replaced.too many battery and control module problems.too costly to replace as often as they give problems...

[@joeshmoe7789]

To test battery cells-Fully charge as normal. Use for about 2 or 3 minutes. Now take apart and test each cell pack or each individual cell. You can run the battery longer, but don't try to discharge.

[@noahking4725]

Ego got a scam timmer

[@summetj]

@@noahking4725 ???