Going through batteries, overcharging?

[rshutchinson]

Sorry for the long post in advance but want to give as much info as possible.

I've gone through 3 brand new sealed AGM batteries now and they don't last more than 40 minutes of riding. Just idling doesn't seem to have any negative impact on the battery though. It's not until I actually take the bike out for a long enough drive that it fails. They exhibit all the symptoms of a dead cell. 12.6 volts when key off, drops down to 2.4 volts with key on. Only load is the led brake light when its not running and key on.

The only thing going is the battery. It's not blowing anything else, fuses or otherwise. I thought after the second one that perhaps it was vibrations so I added rubber feet and a strap to hold the battery down.

It's a sealed battery but is supposed to have vents for overheating and whatnot. However, I don't smell any acid and there is no acid spilling out that I can see nor is the battery hot when I touch it nor any swelling or bows in the plastic.

The bike at idle charges at 13.5v with headlight on, 14.5v headlight off and never seems go above that when revving it up. I haven't left a multimeter on when riding as I don't have a good way to attach it but I'm going to order a small one to monitor it.

My wife rode the bike home today and when I was following in the car I knew it was going as when she came to a stop and the bike came to idle the rear brake light was flickering and got brighter with revs. Next stop sign the bike died when it came to a stop. I was able to kick it back over to start it and told her to keep the revs up when stopping to get home.

I'm assuming the bike is overcharging somehow after riding for a while but I'm not sure. I'll have to get yet another new battery and a new reg/rec combo.

The regulator is the only piece I can't test.

Before I fry another battery is there anything else you can think of that would be causing this? Anything I can double check? I believe I have everything wired right as it all seems to work.

This is really the last gremlin with the bike that is giving me grief.

Thanks guys!

 

[xschris]

What is the charge rate of your batteries. Some are only 13-13.5 volts and can be fried fast. You need to use one that can handle 14.5 + also they need to have good air flow around them or they will over heat.

 

[rshutchinson]

Hey Chris, this is the exact battery I am using. It's meant for Bikes and ATV's.

http://www.kapscomoto.com/product_p/ytz7s-1v.htm

 

[xschris]

Never seen that name before. It also does not state the charge rate of the battery. If you keep blowing them they may be a bad design With a price like that I would believe so. Is yours getting a lot of air flow around it? It also says nothing about mounting in any direction.

 

[rshutchinson]

I'm thinking they're blowing because of something on the bike, not their design but you could be right. It's likely a chinese brand battery but what isn't nowadays. That site I linked to is very popular and I've bought lots from them with no issues. The service rep I spoke with said they sell lots of those and never have issues with them and she sent me another. That's the one that died yesterday.

I don't think it's overheating, it wasn't even warm at all when I checked it. It's under the seat but has louvers directly below it for airflow. They are able to be mounted in any orientation and are vibration resistant as well.


These AGM batteries crank the bike over great for their size. I would get a lithium if I knew the battery was issue but at this point I am hesitant to do it until I know the bike isn't going to destroy it in an hour.

 

[xschris]

This is what I was talking about. It states it's cycle use of 14.5-14.9 volts. yours may only be 13.5 remember your bike has no lights and is not stock like that battery was intended for. If your bike reads 14.5 volts at rev you should be fine. My 80 has a 1.2 ah battery with a cycle use of 14.5-15 volts and has 7k miles on it with no issues. But it is in an open area with full air around it and the bike has full lights.

 

[rshutchinson]

I understand what you're saying. I'll contact them and see if they have that info.

When I've tested it at idle and just revved in neutral it never goes above 14.5v. I haven't been able to test what it is charging at after riding for say 20-25 minutes though. I was thinking that maybe when the regulator is getting warm that it starts failing and is overcharging at that point. But I can't be sure until I try another battery and hook up some sort of meter.

Do you have a link to the small battery you are using? I could get one that you know works and just try it with kickstart only and see if that battery lasts or not. I'd go with the Shorai that I know works but don't want to be out $150 if it dies in a ride too.

 

[xschris]

I got mine 5 years ago and the seller no longer has them. I would look on ebay for something. You can get them cheap. I got mine for $9 shipped.

 

[rshutchinson]

The battery is just a re-branded Yuasa AGM battery so it is fine to take the charging voltages that these bikes produce.


What are possible causes to create a dead cell in a battery so quickly?

I would think if it were shorting it would blow fuses or spark or get super hot and do any of these things almost immediately rather than after riding for a while but I'm not 100% sure.

 

[xschris]

With a custom setup bike it could be a lot of things.

 

[rshutchinson]

I didn't mean specific to my bike, I mean in general so that I can check them out if any apply to mine.

Also, is it possible to use an xs650 reg/rec combo from Mikes on the 80+ 400's?
I've searched and read tonnes of threads but all seem to be all over the place on which reg/rec will work with what bike and for some reason the older 400's don't seem to use the same equipment?

If not, what ones will work with the 80+? The rr38?

 

[xschris]

I only use the stock ones and never had any issues. I think a few guys have tried after market ones but went back to stock after a while. The sohc xs400 used a very common separate solid state regulator and rectifier. There are many still around. Google the part numbers for them and see what come up. I always see used ones on ebay all the time for cheap.

 

[rshutchinson]

Shipping up to Canada is never cheap on ebay or anywhere for that matter so I can't just pick up a cheap used one unfortunately. I'll have a look if there are some from Canada but don't usually find anything.

I don't want to spend half the cost of a new reg/rec combo on just one used 30 year old regulator, I'd rather get new. I don't mind re-wiring if that's required. I'm looking at the Rick's Motorsports reg/rec but if the Mikes one will work I'd use that as it's cheaper and can get it locally.