Sena 20S battery replacement 

Mike - Thank you for this excellent video. Your delivery is perfect and confidence inspiring. My SENA 20S is not functioning at all...no lights red, blue or otherwise. Now, thanks to your fine example, I will order and change mine as well. Thanks for the lesson!

Just finished up, had a third Sena when wife forgot to bring hers on a trip and bough on the road, then didn't really use it at all for 3 years and it died from lack of charging, apparently. I did find a 750mah wattage that had the correct plug on it so that made it so much easier for this inexperienced solder guy. Thanks so much for publishing this terrific how-to!

Mike, your's is a very good, concise video. I just finished replacing my 20s battery maybe 20 minutes ago. Found a seller on eBay selling what seems to be a direct replacement. 650 mAh, 3.7v etc. Comes with the correct plug but with about 1.25" longer pigtail. 1"+ doesn't sound like much but it was a bit much to tuck inside the small 20s housing. On first attempt to mate case halves together I pinched one of the battery leads in two. So back apart and I shortened the leads. Lots of electronics repair experience here so soldering was a non-issue. If I had paid a bit more attention to the insides of both case halves I probably could have more carefully tucked away the excess lead length. So to those not comfortable with cutting and soldering small wires you can most likely be fine. Just be observant of where you tuck the excess. Again thanks for your video. Well done!

Thanks for the great video, I replaced the battery on my hubby's sena in 5 minutes thanks to watching. He's gone through 3 sena's and looks like I need to; #1. replace the other 2 batteries, #2 teach him about leaving them on the charger all the time. Read through all the comments and learned a lot! Thanks to all!!

Excellent. So many videos don't consider lighting. Everything was very clear.

Mike, Thanks very much for your video. I replaced my battery and it went very smoothly. I did have to solder on the connector however; it was no big deal. My battery was 6 years old and at this point the unit does not owe me a thing. Once again thank you for your very helpful video and saving me some money.

Great Video...this was very helpful. Until I did some researching I wasn’t quite sure why my Sena wasn't working nor why it wouldn't charge. It’s not often equipment this expensive craps out for simply a busted battery. Sena needs to do better. Thanks for sharing!

Thanks for this video. Very comprehensive and informative. Sena should provide a link to it since they aren't going to do anything to help. I like my Sena BTs for reliability before they crap out on you, which they will do. Sena's customer service pretends to be concerned about any issues while not doing diddly squat to help the customer resolve a problem. They want you to buy another unit assuming you will upgrade when you do.

First I like my Sena 20s ok, but like you said the speakers are garbage. Now I have one that wont charge so I call Sena and they tell me it's out of warranty buy a new one. Thanks to this video and battery links I can tell them to piss off and I'll never buy anything from them again. Thanks for the video Mike looks easy enough.

FYI, 752439 means that the battery is 7.5mm thick, 24mm wide and 39mm long. So the battery you found is 6.5mm thick, 25mm wide and 40mm long.

Thanks for the video, Mike. Sena replaced one unit for battery failure, then the same one crapped out a year later. Now they won’t help me at all. Screw them, it’s now my mission to spread the word about their crappy product. Now to find the battery.

nice. waiting for my battery to be delivered this evening. I'll take a leap of faith and solder as you did. I've never soldered without twisting or pig tailing the wires, however, i can see it may make things too bulky.

Nice video, the popping off the spin wheel was a big help.I installed a 700 MA battery and it fit fine and had the same electrical connection so it was a breeze.

Worked out great, thank you sir. Changed the battery on my Sena and one for the wife!

Thank you for great video, great walkthrough, saved me $250 bucks! Keep up the good work!

Thanks for making this! I'm sure you have saved a lot of people a couple hundred pounds/dollars. Lots of us owe you a beer ;)

I dont even need to do this but I'm glad I watched it incase I ever need to! This is awesome!

Ditto on the thanks for your video. Just ordered a replacement with correct plug. Sena should be ashamed of themselves for not having replacements available. After years of messing around with headsets, ear pieces, external speakers, etc. I am thoroughly satisfied with Big Ear stereo plugs. Tunes out all noise, to include my Valkyrie truck stacks, and provides good sound at any speed. They are also comfortable.

Thank you, I replaced my with no problem. Yes I needed to change the connector and boy was mu old battery fat. Thanks for your video

Thanks for the awesome video and thank you for the link to that battery. Please don't take this as me being rude, but the way you went about splicing these batteries could have been fairly dangerous. You stripped both leads of the new battery then laid it down on a metal work surface. You probably could have reacted in time to pick it up if it shorted, but had you walked away for anything it very much could have went through thermal runaway and potentially exploded. You can avoid this by soldering one side before stripping the other. Ride safe brother.

excellent video for Sena 20 user's to watch.....Thank you for your great work!!!!

Thank you very much!!! I had the same problem and now everything perfect!!!

Tried this on a 20S Evo. By the way, you can get the battery with the proper connections now on E-bay or Amazon. However, on the 20S Evo, the battery lies beneath the circuit board, which must be removed. I did so with some difficulty, got the battery replaced, and it powered right up. Problem was there was no sound coming through the speakers. This is because getting the circuit board back in properly is darned near impossible. I almost threw it away, but decided to save it to see if any one else can successfully accomplish this and post a video on it.

Great video. This is the Battery I used excel Power Supply DC 3.7V 850mAh 102535 Li-ion Rechargeable Lithium Polymer Li-Po Battery Available at Amazon

thank you Mike! Great video, I will be doing this. I am not drinking the kool aid and replacing perfectly good radios that don't need to be!

Merci beaucoup pour votre vidéo! Petit conseil! Ne jamais couper les deux fils de la batterie en même temps 😉. Ça risquerait d'endommager la batterie. Bonne journée et merci encore!

Biggest lesson I learned from Sena is to NOT throw your Sena on a charger and go to bed. You should charge it and check on it to immediately unplug it when it's charged fully. This will prolong battery life. Great video, thanks.

There's a second battery in the 20s, under the main circuit board. A smaller 100mah 401722.

In your description there is an “update” about s viewer named Chris that has a link to a direct replacement battery. It is incorrect. I ordered the battery and it’s about an 1/8 of an inch to long and the connector is a millimeter or two too large. I ended up having to cut the wires and solder the original plug to the new battery, plus I basically had to jam the battery in like you did. Not what I expected to do. I’m terrible at soldering... At the end of the day my Sena is now working but it was a crappy fix...

My 20s evo is draining the battery fast. I bought it 6months ago from amazon so i dont know why the battery is draining so fast

Why would anyone downvote that video?!?!?! 🤷‍♂️SMH

That part number is the dimensions of the battery. 7.5thick 24 wide 39 long

great video, very helpful, had a dead sena 20s and did not know why, found this video, and saw how easy I could check the battery , and sure enough, that is the issue, link for new battery did not work for me, but I was able to find some. 5 pcs 3.7V 600 mAh Lipo Polymer li ion Battery 602540 power for MP3 DVD GPS PAD. $13 for 5, I could not find a US seller with the correct size and voltage, etc.. and I tried! but basically people can just search for 3.7v 600mah 6mmx25mmx40mm and find options, there are some larger and smaller capacities out there that will fit also, just depends on how long you need it to last, but they get larger in size too and harder to fit into the area allotted for it.

Thanks for your veido very informative 👍

There is also a small battery on the backside of the circuit board 100mah 0.37Wh 3.7V

BrightTea battery above from amazon do not have the exact same adapter. I bought it to skip the welding, but ended up having to swap the adapters anyways. Took a pic, but I can't upload it.

Brilliant!

hey so trying to make the most of my down time here, can't get the top to unmarry from the bottom, were there any model updates that don't allow you to remove the cover after taking out all 5 screws? i did locate all 5 including hidden behind antenna boom

thanks

Awesome video. Thank you.

Do you have a link for the battery

Please, not a big Weller iron/gun. Pencil, pencil, pencil. They cost peanuts and don't melt insulation so fast. Rosin core solder applies flux as it melts. Go for the really skinny solder. The solder melts in a hurry, making tinning and final soldering much faster - less chance of cooking the insulation. As of 6/19, Amazon price is $18.99+5.99 S&H, eBay price is $25.99 & free shipping. Amazon charges sales tax, eBay does, too. Sales tax is the tipping point between eBay and Amazon. The US vendor, Bright Tea, is listed in both places, using the same artwork. The battery includes what looks like the connector Sena uses for their battery.

How about making a video of sena 50S changing the battery.

Hi mike I'm from the uk and cannot for the love of me find a battery for my sets do you know of anywhere I can get them?

Hi bro, greeting from indonesia. I read my sena box it said 20s should last up tp 13 hours talk time. I'm little bit worried about my sena 20s. It last 6 hours. The last time i use it when i was touring to a beach. When it reach 5 hours of usage near the destination, it is still on medium but when im arrived then the battery reach low. Does my battery should be replaced? Any suggestion?

Hi My Sena 10s connector Pogo Pin break how I'll change how I'll get the PoGo pins please advice

Anyone got a link for us Canadians, sense we can get these shipped over the board. Also, all the replacement batteries I have found have been 44mm or 1.73" long and the original is only 38mm or 1.5".

Does anyone know if the 30K uses the same battery ?

I left mine charging for two days. Guess I'm luck lol

Mike Geene, you’re super dangerous with those batteries. When you clipped both leads at the same time you instantly shorted them out. At 6:07 you can see the spark on the old battery, and then you clip both leads again on the new battery after mentioning it yourself that there was a spark. You then stripped both leads right across from each other where they could have easily shorted out right there... not only that but you set the battery with exposed leads on a metal table top... yikes! I know there wasn’t much charge in those batteries, but I have to say that was bad practice and you earned the title of dangerous with electricity. Please don’t attempt to change a light switch or anything of the sort. I am an electronics technician I was cringing the whole time. With all that out of the way, thank you for the video, my battery is on order.

Great the 30k battery is under the board, and i could not lift the board...

Beat you to it did this 6 years ago.

Hold the camera correctly next time you shoot a video please.

That battery was definitely made in China…

Useful, and I bookmarked the amazon link - But don't cut both wires at once please.

Great vid! Used your vid last year to replace battery, then this year after it died again and a replacement didn't work, I pulled out the circuit board and discovered another tiny bloated battery underneath it. Are you having any issues with yours again?

Thank you for such an informative easy to follow step by step video to replace the battery in my Sena 20s. Infact, once I easily replaced the battery in my 20s I purchased a battery for my old 10s in my other helmet and replaced it to.

this is so amazing at the same time very disappointing to sena

Thanks so much for the video! Ordered a replacement battery on ebay, there seem to be plenty of sellers and a few in the US.

Does anyone know where the internal microphone is on the board? Great video will be nice to know in the future

Thank you for the video, I was grateful to know I could fix my Sena. We also found batteries with the right connector.

Some do seem to use T7 Torx as well, great video!

Wow. I left the last comment a few weeks ago and a second Sena died on me. 2 for 2 on the fix and I have a third I think I’ll proactively repair given the first two died at the same time (about 5 years old). Thanks much for this tutorial!

Thanks heaps

Hi Mike! Thanks for posting this video. Would you have the dimensions of the original battery?

You're right, Sena told me you cannot charge these units longer than 3 hours. For example, don't plug in before bed time! :-) It apparently degrades the batteries.

Hey bro maybe you know the name of the USB port for the speakers? I need to find a replacement for that but can't cos idk the name of it

This is the battery spec that Sena provided to me when I asked about battery replacement for my Sena 20S : Capacity: 650 mAh 3.7V 2.4 Wh Dimension: 752439 So, when searching Google for "3.7V 650mah" include the 752439. I found two possible replacement batteries. Also, this youtube video was recommended by Sena support but in this video a toy drone LiPo battery is used to replace the OEM Sena battery which has different wire AWG (gauge) and connector. the OEM connector is a JST PitcH 1.0 mm 2 PIN connector which these two AliExpress batteries have. I purchased the link 1 only because link 2 was a minimum of 5 batteries. Also, the website for these two links below was the only one with 752439 in the search criteria. Important note about Li-polymer batteries. I fly drones as a hobby and all powered by Li-Po. here are a few things I've learned about these batteries: Fully charge battery before use. power on 20S lLED flashes 4 times then it's 70-100% 2 flashes 0-30%. DO NOT charge battery immediately after it is depleted and still warm. Allow it to cool down for about 15 minutes. It is not over charging that causes Li-Pos to balloon it is charging an already warm battery and over depleting or over discharging. Eventually they all swell a little anyway so you can buy more battery life by following these tips. 1. link www.aliexpress.com/item/XHR-2P-1-0-802540-3-7V-800MAH-Rechargeable-li-Polymer-Li-ion-Battery-For-bluetooth/32841845070.html?spm=2114.search0604.3.1.66454614TLVGie&ws_ab_test=searchweb0_0,searchweb201602_1_10065_10068_10130_10890_10547_319_10546_10548_317_5734611_5730311_10545_10696_10924_453_10084_454_10083_5729211_10618_10920_10921_10922_10307_537_536_10059_10884_10887_10928_100031_321_322_10103_5734511-10890,searchweb201603_51,ppcSwitch_0&algo_expid=72c9c10b-2cc7-4218-aa3d-3ef99485aeba-0&algo_pvid=72c9c10b-2cc7-4218-aa3d-3ef99485aeba and 2. link www.aliexpress.com/item/free-ship-5pcs-lot-3-7v-702540-752439-750mAh-polymer-lithium-battery-li-po-rechargeable-battery/32823579892.html?spm=2114.search0104.3.2.16475490Ou22ci&ws_ab_test=searchweb0_0,searchweb201602_1_10065_10068_10130_10890_10547_319_10546_10548_317_5734611_5730311_10545_10696_10924_453_10084_454_10083_5729211_10618_10920_10921_10922_10307_537_536_10059_10884_10887_10928_100031_321_322_10103_5734511,searchweb201603_51,ppcSwitch_0&algo_expid=fa0867af-f0f5-4f02-abd3-de0a3950f51c-0&algo_pvid=fa0867af-f0f5-4f02-abd3-de0a3950f51c

The link to the battery is dead

Very useful video. I changed my battery with a replacement from Snackazon in 15-20 minutes. The replacement battery had the right connector, so it was very simple. Testing shows battery duration at full volume (I wear earplugs) for at least 6 hours.

Hi mike, good video by the way, can I ask when your sena went dead, did the charge light stop glowing red and did the sena just become dead with no life at all? I ask because mine has died but I managed to put a multi meter to the battery and it showed 3.8 v , this lead me to believe my battery was fine, also my talk/music time was still lasting fine as it’s only a year old but rarely used. Sena are being very difficult and it could cost almost $200 Nz to send and receive back from Sena USA. To be honest I’m very disappointed with the customer care, I feel like I’m talking to robots with no feelings or reactions . Any help as to why it has died will be much appreciated. Ps I’ve tried the reset button on the back of the unit multiple times and still nothing, Regards Pete 👍

Hey Mike, helpful video! I'm unable to track down a replacement battery. Do you have a link to the one you used? The link you posted does not work for me. Thanks.

Any one know what type battery connector that used? Please answer...

is this possible for sena sf4 ??

I was able to find a direct replacement battery with correct plug. Thanks