I recently had an issue with a weak battery on my brute force and I was wondering if anyone can explain a few simple items to me:

1. On the new Brute 750 EFIs, assuming you have enough battery to start the quad, will the quad produce enough power to ride even on a weak or non-charging battery?

2. Does the Brute actually charge a batter via the generator or does it simply just maintain the current battery level, requiring a battery tender to be used during storage?

3. Does the EFI and computer run of clean power, aka the battery, making it even more important to always have a strong battery?

4. Accessories, like winches, etc. Are they setup to pull from the battery VDC before using any engine supplied VDC ? If so, what happens when the battery VDC is too low to run the winch, will it actually take juice away from the EFI and Computer, causing the Quad to die?

Sorry for all the questions, I am trying to wrap my head around an issue I had with my new quad, where it would run for 10 mins until I engaged the winch a few times, and then it would die, and I would not have enough juice to restart it. I added a new battery and the problem seems to be gone, but I was told by the dealer that the quad does not charge the battery, only maintains it and that comment bothered me a bit..for obvious reasons...due to the face that there is no way to manually start this quad, dead or weak battery = walking...

Thank you in advance for any insight this, and any workaround other than plugging it into a tender after each ride..

 

<div class="FTQUOTE"><begin quote>Originally posted by: ruetheday69
1. On the new Brute 750 EFIs, assuming you have enough battery to start the quad, will the quad produce enough power to ride even on a weak or non-charging battery?
</end quote></div>
Yes & No.
Yes, the 750's alternator has enough output capacity, 24.3 amp @14VDC, to charge up a reasonably weak battery.
No, the quad won't bring back a too weakened/sulfated battery back to full life. Once the AGM battery is sulfated, like the Yuasa in BF, internal shorting happens between the divided cells inside the battery. Too weakened AGM batteries can rarely come back to full life. It is extremely important to keep the AGM batteries fully charged during long storage period to prevent the permanent internal sulfation.

<div class="FTQUOTE"><begin quote>Originally posted by: ruetheday69
2. Does the Brute actually charge a batter via the generator or does it simply just maintain the current battery level, requiring a battery tender to be used during storage?
</end quote></div>
Yes, the battery gets charged by the alternator (not generator).
Yes, quad's battery should be hooked up to a "automatic" battery tender when not it use. If you don't use automatic type, the battery will be cooked.

<div class="FTQUOTE"><begin quote>Originally posted by: ruetheday69
3. Does the EFI and computer run of clean power, aka the battery, making it even more important to always have a strong battery?
</end quote></div>
Yes, the battery is more important on EFI models because EFI system uses voltage level as feedback signal between ECU and many sensors (TPS, CPS, Temp sensors, etc.).

<div class="FTQUOTE"><begin quote>Originally posted by: ruetheday69
4. Accessories, like winches, etc. Are they setup to pull from the battery VDC before using any engine supplied VDC ? If so, what happens when the battery VDC is too low to run the winch, will it actually take juice away from the EFI and Computer, causing the Quad to die?
</end quote></div>
If your quad is using more watts than what your quad's alternator is making, the battery will be taking a toll and the EFI system would not work properly. It's like you are spending more $$ than what you are making - your bank account will bottom out and checks will be bounced. The maximum watt usage should be lower than the maximum output capacity of your alternator which is about 340 watts at 6000 rpm (WOT). If you are just idling or running the quad at low rpm, the alternator output will be less than that. So, when using a winch or some other high watt accessory, rev up the engine to make up the increased watt usage to save the battery. Again, if you would be spending more $$ than the usual, work overtime to make up. Hope this analogy explains.

 

Thanks Hayashi!

Turns out I had the charging systems checked out, no issues there..this all boiled down to a cheap and weak factory battery that got even more hammered when the winch was used. I just wanted to be sure that the Quads alternator DOES charge the battery..the dealer made a comment that indicated that it only "maintains" it at its current level and I didnt agree with that. Are there any alternatives to the factory battery that has proved to be a better battery .. all around..like teh Optima Gel Batteries that I have on my camper?? While more expensive..they have proved to be well worth the expense. For example...I leave them in an unheated garage all winter long with no tender..and for over 5 years they have still worked perfectly...wonder if I can find a similar battery for the quad...any ideas?

 

I've had the same stock battery in my V-Force for 5 years now. It lives in an un-heated garage where last night the temp was -30C It has sat on the lake overnight in the wind at -40C

I do not believe that there is a better battery than the Yuasa that comes with them.

My .02

 

<div class="FTQUOTE"><begin quote>Originally posted by: ruetheday69
Are there any alternatives to the factory battery that has proved to be a better battery .. all around..like teh Optima Gel Batteries that I have on my camper?? </end quote></div>

Yes, there are some better quality batteries out there than Yuasa which is still slightly better than some other known cheaper ones like Exide, Delco, Interstate, GS, etc.

As you just mentioned, Optima is one hell of good brand as its price might give some indication. Another brand that you should check out is DEKA which is one solid quality battery. It doesn't sulfate as easily as Yuasa would even during long storage period. Another difference is that it would come back to life even after its terminal voltage drops below 10 vdc. At that low level, Yuasa is a goner forever. This is from my personal experiences.

The reason why your factory Yuasa had that ill fate on your quad is probably due to improper "initial" charging method that whoever (your selling dealer?) did that in first place. According to Yuasa, it is supposed to be very critical to its total lifespan (it could be as short as 50% if done not right). No other battery manufacturers emphasize that as Yuasa does. Yuasa is OK for land-use recreational vehcles like quads, but I would not use that on my off-shore fishing boat that I take out 50+ miles away from the main land.