Yet another battery thread

[chessie4905]

I use Pulse Chargers on my batteries. You can also buy a unit that will maintain each battery a given amount of time, then switch to the next.

[Jim Blackwood]

Sounds expensive. Well, the Stark also does 12v/34A if I needed to use it that way but with the other chargers I have it's pretty pointless to do it I think since I can just use one of them. Maybe for reconditioning but if I keep these two 8Ds topped up shouldn't it be a few years before I have those problems? That's the issue for me. I'm lousy about battery maintenance and I realize it. Got a lot of batteries around the place and they all get about the same attention, which is basically to replace them when they go bad. I know, that's horrible. If I was retired maybe I'd have the time to do it right... no, wait. I AM retired. Oh, it's hopeless. A couple bills is all I can swing and you don't get much for that these days. I'm feeling poorly after buying all that stuff for the bus. I don't understand how these fancy chargers are supposed to work so it's hard to justify the extra money.

Disconnects are a good idea but the only easy to use,  reliable yet reasonably inexpensive ones I am familiar with are marine battery switches. Which are pretty good but still cost money both to buy and to install, and then still don't solve the charger issue. I like the fact that you can open a small door and throw the main disconnect. It'd be nice if that was all you had to do.

Jim

[Jim Blackwood]

Andy says the military are using a matt of solar cells on the roof of their vehicles because they spend so much time in storage. Seems like a reasonable idea, don't need enough capacity to recharge or carry loads, but enough to keep the batteries from running down. What would be suitable for a bus?

Jim

[dtcerrato]

We have a measly 500W split system. 400W on house bank & 100W on the starts. It's great - lot less need to charge with the pole nor the genny.

Andy says the military are using a matt of solar cells on the roof of their vehicles because they spend so much time in storage. Seems like a reasonable idea, don't need enough capacity to recharge or carry loads, but enough to keep the batteries from running down. What would be suitable for a bus?

Jim

[kyle4501]

My knowledge of chargers is quite limited, but as I understand  -
- the lowest voltage cell tells the charger when to start.
- the highest tells it when to stop
- disconnecting batteries reduces the number of cells
- 'smart' chargers are better at getting all cells up to the same level of charge
- 'smart' chargers WILL NOT work as well if there are ANY loads attached to the battery (disconnecting solves this)
- 'smart' chargers have limits as to how big of a battery they can charge effectively

I was having sporadic starting issues which lead to a dead starter -- so-- I got some Cole Hersee switches off ebay (- 1/2" stud rated at 300A continuous/2000 start ), a hydraulic crimper, wire & lugs to make my own cables. Was not cheap, but I haven't had any issues since. (now it is easy to make custom cables anytime I need)

My experience is it usually costs less in the long run to do it right the first time 
The only thing cheap about these big rigs seems to be the owner 

A wise man once told me " If you are going to eat like an elephant, expect to poop like one too"   

[Jim Blackwood]

Seems reasonable but... the charger can only see the total of all cells in the battery. Because the cells are in series there is simply no way to differentiate one from another. Of course low voltage can indicate a bad cell but no way to say which one. I think about the most you can hope for is that by splitting the bank you can at least tell which battery has a bad cell and then the hydrometer can tell the rest.

But as to the finances of the situation. I'm on a fixed income with a nest egg. When Edith retires I may be able to look to her for additional funds if she deems it worthy. No guarantees but I am ever hopeful. And there is at least the possibility of a modest inheritance at some point. So I need to be circumspect about my expenses. House batteries will be one, tires will be another, and those are pretty much unavoidable. In the meantime there is much to do. AC compressors will approach 2 grand for instance. There are some things I can do to keep costs down and some I cannot and quite a bit of it is discretionary. The battery charger falls into that category.

On one hand, I can disconnect the batteries at the terminals and use my 6/12v 200A processor controlled starter charger by moving it from battery to battery periodically, checking electrolyte, and only attaching the leads when needed. Cost: absolutely nothing but labor even should I need a bit of battery acid which I have on hand in more than adequate quantity, for anodizing. But the labor is more than I am happy with.

At the other end of the spectrum I can pay a couple grand for a high powered inverter, buy an expensive hydraulic cable crimper and cables, and fit each battery with it's very own disconnect, even use contactors and remote controls if I like. And maybe plate the top of the bus with solar cells.

I consider both ends of the spectrum to be undesirable for a number of reasons mostly having to do with convenience on one hand and cost on the other. What I'm looking for here is a modest means of removing the worst of the inconvenience while enhancing the reliability overall. As mentioned I'm not historically very good at battery maintenance, and I want to give my brand new start batteries the best chance for a long life. To me that means an onboard charger of some sort that will hold up for the long haul, simply for maintaining the batteries. I thank you all for all the valuable input.

It's not decision time yet. NAPA tells me the batteries will be there tomorrow. So there is still time to think about this and solution #1 will suffice short term. But I have no intention of leaving my best starter/charger sitting out in the rain next to the battery compartment any longer than I have to.

I also noticed that nobody had anything to say good or bad about the automatic watering system to keep the electrolyte level optimized. Has nobody else heard of this?

Jim

[belfert]

I have four group 31 AGM batteries to start my bus.  I could probably get by with two batteries, but I didn't want to figure out how to rewire things at the last minute.

I use a Battery Tender 24 volt charger to keep the start battery bank charged when the bus is not in use.  The Battery Tender can't be doing too bad as my starting batteries were purchased in December 2010.

[Jim Blackwood]

Thanks. Apparently there are several.
Currently I am using this as a baseline for comparison:

https://www.ebay.com/itm/303477514107?chn=ps&mkevt=1&mkcid=28

Microprocessor based, 12v/24v and 35A continuous charge rating. Plus the large cabinet would seem to indicate good power dissipation. There should be a decent possibility of removing it from the case for a custom install. I've been inside an old manual one changing the rectifier over to the diode pack out of a big GM alternator. 

More than I'd like to pay but it seems to be good value for the money. I'm used to this type of charger, having one in 6/12v and the old manual one that I use when brute force is required. Neither really suitable for the bus though.

Jim

[buswarrior]

I don't want automatic watering, because i want to know what's going on.

Water use by batteries is a delicate balance between using them, and abusing them. Too much water consumption, and the batteries are being beaten by the charging equipment, or a cell is on the way...

Automatic filling leaves you ignorant and blind as to what condition your batteries are in, in an individual manner.

Happy coaching!
Buswarrior

[richard5933]

I don't want automatic watering, because i want to know what's going on.

Water use by batteries is a delicate balance between using them, and abusing them. Too much water consumption, and the batteries are being beaten by the charging equipment, or a cell is on the way...

Automatic filling leaves you ignorant and blind as to what condition your batteries are in, in an individual manner.

Happy coaching!
Buswarrior

The flip side is that for a battery bank which is difficult to access a watering system makes it possible (easy) to stay on top of things and not neglect adding water because it takes too long or is too difficult.

In an ideal world, your plan works great. Many of us have battery compartments which are made up of a few compromises.

[luvrbus]

Jim if you are going from post to stud cables invest in military grade adapters saves you a lot of grief later,I never knew why all military batteries are post then to stud cables but there has to be reason I guess 

[daveola]

I use an IOTA charger in parallel with my inverter, they are a decent price for a large amperage charge, and they have 24V options as well as the ability to buy modules to intelligently charge different types of batteries (I have a large AGM bank).

Having said all that, I'm going to trash my whole battery system and switch to lithium - I've had enough with silly lead acid and AGM batteries and their inability to discharge without getting damaged.  So I'll have an IOTA 24V charger and a Xantrex SW4024 up on ebay in the not too distant future. 

[windtrader]

Be bold, just make a single bank, simplify your charging, and with a combination of smart equipment, and your own vigilance, just save the money and hassle of 2 different banks to take care of?

That is what I will likely do when the current pair of group 31 start batteries are done and dead. The main house lithium bank has plenty to start the bus and is constantly topped each morning then charged as needed during the day.


One concern unresolved is using the house bank while the bus is running. It is no big deal to get the house to start the bus but not sure I like having the house and bus connected while running. Not worried about the drain but just the idea of connecting them together is a bit worrisome.


There might be a path to downsize or ditch the alternator if using the house bank only as it is charged via solar or generator if necessary.

[richard5933]

That is what I will likely do when the current pair of group 31 start batteries are done and dead. The main house lithium bank has plenty to start the bus and is constantly topped each morning then charged as needed during the day.


One concern unresolved is using the house bank while the bus is running. It is no big deal to get the house to start the bus but not sure I like having the house and bus connected while running. Not worried about the drain but just the idea of connecting them together is a bit worrisome.


There might be a path to downsize or ditch the alternator if using the house bank only as it is charged via solar or generator if necessary.

A safe way to do this is with a battery-to-battery charger. Sterling makes some nice ones which are true multi-stage smart chargers and which have settings for lithium. I'd think having a battery on the bus side to help smooth out the power would be helpful, even if it's just a single battery.

It would be nice if there was an engine mounted alternator which was setup to safety and properly charge lithium battery banks like you'd have, but I don't think I've seen one yet. With something like this it would be much easier to have a single lithium bank.

[luvrbus]

Some people spend a ton of money on a battery bank ? why,I stopped in Fallon Nv to help a guy in a GM 4104 that had just spent 12 grand on Battle Born Lifepo batteries. The bus was worth about 5K tops probably less with a blown 6-71.I cannot see people paying 10 bucks a amp hour for batteries plus the solar system