3 batteries 1 tender?

I have a Dynamark high reach 39'9" extendable forklift. it is like a SkyReach. Powered by an industrial JD motor. It has 3 batteries in series. These are large 12V batties, but still tractor/auto size. I was wondering if I could hook a cheap HF battery tender on the 1st battery, there by keeping all 3 batteries charged. I will not be using the machine much if any this winter. TIA...MTP

We run one on a combine with 2 group 31 batteries. Worked good.

If they are in series no. That would be a 36 volt system.

You are talking parallel and that would measure 12 volts. Answer is yes. The other way is 36 volts and things would kinda smoke.

OK, this is how they are wired. Left to right. 1stBattery + terminal,jumping to 2nd battery + terminal,2nd battery + terminal jumping to 3rd battery + terminal. Power then is sent out of the 3rd battery to the system. The - terminals are wired the same way...TIA...MTP

Tender would be put on the 3rd battery...Right? MTP

(quoted from post at 17:40:45 12/16/15) I have a Dynamark high reach 39'9" extendable forklift. it is like a SkyReach. Powered by an industrial JD motor. It has 3 batteries in series. These are large 12V batties, but still tractor/auto size. I was wondering if I could hook a cheap HF battery tender on the 1st battery, there by keeping all 3 batteries charged. I will not be using the machine much if any this winter. TIA...MTP

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I bought a HF tender a few years back and it cooked my batteries....beware!

Hmmm. Makes a guy think. Were you tending just 1 battery or something like I'm talking about? I'm gonna do some Gooooogle-ing when I'm done here. Thanks for the advice...MTP
Thanks for the replies everyone, I would like to hear more yeas and nays... What does everyone think about the cheap HF tenders?MTP...

The key words that got me were "Cheap" and Harbour Freight" - that is a given. However, if you want to take care of your batteries, spend a FEW dollars more. If the units are in parallel, disconnect the plus and negative cables to the machine and you may be 'good to go'. Again, "cheap" is not an answer. HTH

(quoted from post at 20:48:18 12/16/15) OK, this is how they are wired. Left to right. 1stBattery + terminal,jumping to 2nd battery + terminal,2nd battery + terminal jumping to 3rd battery + terminal. Power then is sent out of the 3rd battery to the system. The - terminals are wired the same way...TIA...MTP

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All 3 batteries are hooked parallel, meaning you can hook the batt tender up in any configuration you want, it doesn't even need to be on the same battery as long as you keep the batt tender leads hooked up correctly.

There are a couple problems with using a single tender on multiple batteries.

Are you having problems with the batteries going down when sitting? If so, either one battery is weak, and it's drawing the other 2 down. Or there is a drain from somewhere in the lift truck.

If there is a problem, and all 3 batteries are left connected, and connected to the lift, the tender will never be able to bring them up and drop out. It will keep trying, and eventually cook the batteries.

My suggestion, since you are not going to be using the lift all winter, would be to disconnect all the batteries (only one terminal per battery necessary) from each other and from the lift. Then when you are ready to use the lift, check each battery. If one is dead, it was bad. A healthy, charged battery will easily hold a charge for 3 to 6 months.

Or, if you want to invest in tenders, get one for each battery, store the batteries disconnected from each other.

In any case, disconnecting the batteries from the lift would still be a good idea. Those have a lot of electronics on board, mice like to chew and pee on stuff like that when it's stored!

All 3 batteries were bought and replaced in 2011. They have held charge through prior winters fine. At the price of batteries these days, I don't feel like replacing them yet or in the spring for that matter. I was working the lift a few months ago. I was on a semislope, so I had the body rolled to compensate the grade. I blew a hydraulic cylinder on it. I limped it back across the road as fast as I could. It was spraying fluid all over the place. I got it to a place I could shut it down, until I could get the cylinder rebuilt. Needless to say leveling the body prior to shut down was the last thing on my mind. I put the cyliner back in. Then was looking at all the acid crud on the post/cables. I cleaned them up, and charged the batteries. I had to charge them about 3 times before I got it to start.
The batteries seem weaker or with the body rolled the battery plates may not have been covered with acid, time will tell.
As soon as it started ,I warmed it up for couple minutes ,then I leveled the body. I then started working the hydraulics to bleed any air out of them. I drove it up to my pole barn and shut it down. Tomarrow I am going to check the air preasure in the tires and work all the hydraulics more. I will also check fluid level in the batteries and then put a load test on each of them. Thanks for all the advice [email protected]
P.S. Steve I've been working on the F600 wrecker. Please check back on that post, as I posted an update and want your opinion...page 6 or so... Thanks MTP...

P.S.S. Steve if one of the batteries check out weak/bad now or sometime down the road, do I have to replace the set? I had always heard, that if one is bad they all should be replaced.I would just put the other 2 in my diesel truck or split them up and use them in other things...TIA...MTP

If your in it for the long haul, bite the bullet and get a 3 bank battery tender like they make for boats. Not cheap, but they work great.

I'd do what Steve suggests, disconnect them from each other and move the tender to a different battery every few days.
If you do decide to do 3 at once, keep an eye on the tenders temperature.
I've used tenders, voltage correct, but outside the design specs before. They did what I asked, but got hotter than I liked while doing it.

Hello Michigan's,

I would think you have a 12 volts system which means you have a parallel system. Schumacher makes a very good battery tender. Cheaper then buying batteries, and yes you will need 3 of them,

Guido.

Mike, the problem with changing one and leaving the others in the same vehicle, if another goes bad it will drain the new one, then over charge it when it's running. Splitting them up is no problem, that's the best way to put what's left of them in use.

As far as the acid and corrosion on top, depends on how it got there. If it was tilted far enough, and the batteries were full, it may have just ran out the vents. That acid/corrosion mix is conductive and could have caused a drain on the batteries. Now that it's clean they may be OK. But, if the acid was there because it boiled up out of the batteries, that's a sign they may be getting near the end. The alternator is having to work them hard to get them up and keep them up.

Steve thanks for clearing up my questions. When winter does finally set in, I am going to pull the batteries and put them on tenders. I already have 3 new HF tenders, I'll use them since I have them.
I didn't get much done to the lift today. I put the battery charger back on the batteries. It only charged 10 or so minutes. I really don't know when it kicked off , as I was filling the first tire. I did check/air the all the tires up. Then check the H fluid, I had already put 5 gal. in the lift. I added almost 4 more today. I then replaced the rubber mat that was on top of the batteries with a new one. The rubber mat is to keep the batteries from shorting out when the steel battery cover is put on. I did not try to start the lift before or after I put the charger on.
So, I lost right at 9 gallons of hydraulic fluid when the cylinder blew. I still need to work/extend all the H cylinders. I needed to make sure the tire presure was right, before getting to Wacko with the the lift. Leverage is a great and dangerous thing with these machines. Thanks Steve/everyone...MTP

Not a problem with a 3 battery parallel hookup. My two Steiger tractors and the semi tractor all thave 3 grp 31 batteries in parallel.

In the off season, I keep them maintained with a BatteryMINDer cjarger / maintainer/ desulfator.
Dont buy a cheap maintainer and risk a fire or battery damage. The BatteryMINDer is a high quality unit that will maintain 3 batteries at the same time. I have used 4 of them for 10+ years and added 4 more when they were discounted to $20 a few weeks ago.
Thir still at $25 at Northern tool, very good units.
Battery minder.

I hook up three tractors to a tender, haven't had any problems.

Jon, thanks for the link/advice...I'll check them out online later or look through my catalog...MTP

I checked the link out... They look good, thanks again. MTP

Your welcome. If you read down in the BatteryMINDer spec sheet, their good for up to 4 batteries on 1 unit.