Why does the Transit have 2 batteries
- Thread starter acvox24
- Start date
They're for different uses, although you can get a starter agm...agm is definitely better, no maintenance leakage or off gassing but more expensive... there's some recent threads that cover it in detail I'll post when I find it...btw how's your mileage? I like the Ford but not enough to pay that much...im cheap..
The BAGM-48H6-760 battery is kind of a smallish battery. It's Group 48 (sometimes referred to as H6, or in this case, both), and has 760 CCA. It also has a RC (Reserve Capacity) of 120 minutes, and an Amp Hour capacity of 70 Ah. These new vans have a lot of electronics, what with everything having sensors and a computer to control everything, so they need more capacity more than they need CCA, really. 760 CCA is probably more than enough to start the engine, but doubling up with two batteries gives you plenty of amps even in extreme cold, and lots of capacity to keep the electronics going, some of which have rather high amp draws. Having two batteries, with them also being AGM, puts a lot let strain on the charging system, as well.
Yeah, they're 12 volt batteries, so wiring them in parallel (+ to + and - to -) doubles the capacity (amp hours), the CCA and Reserve Capacity of the batteries while maintaining the same voltage of one of the individual batteries. By doubling them up in parallel, you effective have one large battery with 1520 CCA, 240 minutes of RC, and 140 Ah capacity.
It's WAY better if you do, because AGM and regular wet cell batteries require different voltages with which to charge them up. They also require different charging regimens, as well. Basically, AGM batteries require higher voltages, but the charging amps can be all over the place, whereas wet cell batteries require lower voltages and more of a constant charging current. Trying to charge wet and AGM batteries with the same charging source (alternator) is virtually impossible, which means one battery or the other will be chronically undercharged or ovrecharged. In your case, the Transit will charge the vehicle's AGM batteries properly, but will overcharge a wet cell battery bank. Using AGMs for the battery bank ensures all of the batteries get the proper charge.
All things being equal, AGM is hands down better than wet cell. AGMs won't spill because there's no wet liquid sloshing around inside/ Instead of free-flowing battery acid, the acid is contained within a fiberglass matting material (Absorbed Glass Mat - AGM). They are more tolerant to heat and cold/ They have a very low internal resistance so they'll self-discharge at a much lower rate and will recharge much quicker, and they have a 2-3 times longer life than wet cell batteries.
Turtle, so are those deep cycle batteries. That more than my house battery(bear in mine all I use it for is to power my laptop , big video gamer got tired of running the geny all day just for games). Going to be adding an espar before winter. Reason I'm asking is should isolated one for the truck and run the other parallel with an added deep cycle AGM. I'd be using a switch(I'll include pic). Or leave the 2 for the truck.
No, not really. But they're close. They're more like a hybrid marine or truck battery than a true deep cycle battery. They are just deep-er cycle than traditional wet cycle batteries. They can handle low amp draws, like in the case of a marine (or truck) battery, the draw of running lights or a trolling motor. They aren't designed to deeply cycled, for high amp draws, or for long-term sustained draws of any kind.
AGM batteries are constructed differently than the traditional flooded battery, in that instead of free flowing electrolyte, there is a thin ultra-fine fiberglass mat sandwiched between the plates that are saturated with battery acid to about 95% of what they can hold. This mat is then packed in between the plates and slightly compressed, then welded/soldered in place. Because the plates and mats are packed fairly tight, they are almost immune to vibration (which is why they were developed and used initially for military aircraft). But just because a battery is AGM does NOT make it a deep cycle battery. Several companies, such as Optima, have adopted AGM for starting batteries and other non-deep cycle applications. That's what you have (not an Optima, but the same technology). Those batteries still have the advantages of AGM (non-spillable, low internal resistance, rapid recahrge, etc.), but are not deep cycle. It is primarily plate thickness (and plate height) that makes a battery deep cycle, not whether it is flooded, gelled, or AGM.
Leave the 2 for the truck. Don't mess with the truck's charging system. Use the truck's starting batteries to start the truck and to handle all of the truck's electrical needs, and use a separate house battery (or battery bank) to handle your own needs inside the truck.
Your current house battery, the Duracell SLI31MDC is a hybrid "deep cycle" battery that is essentially a standard Group 31 truck battery or a marine battery with 105 Ah of capacity (at the 20 hour rate). The label showing the 225 minute RC capacity at 23A is a marketing gotcha that, frankly, should be outlawed, as the most common method of publishing RC is at a 25 amp draw, which in this case would produce a RC of 185 minutes. It's not a bad battery by any stretch, it's just that it's a dual purpose battery designed for starting and for low amp draws, like for running lights, a trolling motor, or a sump pump.
One immutable truth about batteries and capacity is, the more lead you have (and thus the more the battery weighs) the more capacity you're gonna have. Your battery is a 59 pound battery. And like most batteries in the 60 pound range, you're gonna get about 105 Ah out of them. The RC (and the Ah to a degree) depends on the amount of lead and the lead plate construction. Thicker and taller lead plates means more RC. That's why the RV crowd likes the Trojan T-105 golf cart batteries, which are 6 volt batteries, wired in series, to get 12 volts. Each of the 6 volt batteries weighs 62 pounds. Put two together and that's a lot of lead. (I have four 6-volt batteries, each weighing 83 pounds, for 610 Ah of capacity).
You don't need a really high dollar battery for the house battery, but you should swap that flooded battery out for an AGM so it'll be charged properly.
The Espar heater uses far less electricity than many people realize. The D2 draws 8.3 amps at startup, but that's only for a few short minutes. At Boost, which it can run at 10 or 20 minutes to get a cold truck all warmed up inside, draws only 2.8 amps. Once things reach the desired thermostat temperate range, it'll bounce between Low/Med/High which draws 0.7/1.0/1.9 amps. If the van is insulated, over the course of 8 hours the Espar will draw probably 1.1 amps per hour, for a total of like 9 amps, maybe 10. That's it. I have the D4 and it spends most of its time either on Low (0.6) and Med (1.1) so it averages an amp or less per hour.
That's not to say you should be running your Espar off the cranking batteries, even though you totally could. The colder it gets outside the fewer amps (and CCA) the cranking battery will have, and the lower the temperate the more amps are required from the battery for a given task, so those 9 or 10 amps from a cold battery under the hood could really be between 20-30 amps, and you really don't want to draw out more amps from a battery that's already down on amps because of the cold. Much better to run the Espar off a house battery and leave the truck alone.
The laptop (2.34 amp draw, 9.23 amp @ 19.5V output, boy that's a healthy laptop!) will draw more than you'd think, but probably not as much as the label might indicate. The input, or what it draws from the inverter or the household power plug, is 2.34 amps, but that's based on a wide range of 100-240 volts. But, let's go with 120 volts. And amps (2.34) times volts (120) equals Watts (280). So, your laptop, while charging, draws 280 Watts. 280 Watts divided by 12 volts from the battery gives you 23.4 amps from the battery.
That's a lot. But it probably won't be that much. That will only happen if the battery is charging and you're using the laptop and the laptop is doing everything it knows how to do, all at once (like, max screen brightness, while playing a video game while watching a DVD while defragging the hard drive and downloading gigs of movies via WiFi). The laptop will draw only the power it needs at any given time, so once the battery is charged, while you're using the laptop it'll draw more along the lines of 5-6 amps.
5 amps is, incidentally, the rate of draw that a 100 Ah battery uses to obtain it's 20 hour rate. The AH rate of a battery is whatever draw is required to run the battery dead in 20 hours. So in the case of a 100 Ah battery, it's 5 amps. Since you don't want to draw the house battery down more than 50% (to prolong the lifespan, even with an AGM battery), that tells you the laptop can be run for 10 hours before the battery is 50% down (assuming nothing else is running off the battery). But of course, the inverter is going to scarf 1 to 1.5 amps whenever it's on, so you lose some there. But you get the idea.
If you're on the laptop and the Espar, figure about 7 amps per hour. If you use an under-cabinet kitchen LED light for lighting in there, add another half an amp or so.
You may want to get two batteries for the house bank, depending on just how much you use the laptop, or you might want to get a couple of 6-volt batteries instead of a pair of 12-volt batteries. The Trojan T105-AGM (Group Size: GC2) is a 6-volt battery that will give you 217 Ah, 440 RC, and weigh 68 pounds each. SunXtender AGM batteries are identical to and made by Condord Lifeline (the inventor of AGM batteries) with a slightly different warranty. If I were to get an AGM battery right now I'd get either a SunXtender or a Trojan. Fullriver (made in China) are good batteries, but they have a slightly different AGM chemistry than the Ford battery, so I'd have to do a lot more research on that one with regard to mixing those battery types and charging before I'd recommend it. Odyssey makes a really good AGM deep cycle battery, as does Deka. Duracell brand is good, just be careful as to which kind of AGM you get (general purpose, which is a hybrid, but still OK for your use), Deep Cycle (true deep cycle), or High Rate UPS AGM (for emergency, critical power, not suitable for everyday use). Crown Battery (Freemont, OH) makes a good AGM battery. A marine AGM (hybrid) found at Cabela's or some place is fine, but if it were me I'd just get a true deep cycle battery.
I worked for a military contractor for a while.
Initially the M1A2 Abrams tank had 6 flooded lead acid batteries ($75 each). Later versions of the tank had ten AGM batteries ($250 each). We had to get chargers that were constant voltage, around 15.2 volts or so, to full charge them. Then their internal resistance was measured and the closest batteries were paired in series. Three series pairs connected in parallel on one side, two pair on the other.
On one tank we broke the alternator driveshaft in the transmission. Apparently a 650 amp oil cooled alternator will max out with ten dead batteries. Oopsie.
Initially the M1A2 Abrams tank had 6 flooded lead acid batteries ($75 each). Later versions of the tank had ten AGM batteries ($250 each). We had to get chargers that were constant voltage, around 15.2 volts or so, to full charge them. Then their internal resistance was measured and the closest batteries were paired in series. Three series pairs connected in parallel on one side, two pair on the other.
On one tank we broke the alternator driveshaft in the transmission. Apparently a 650 amp oil cooled alternator will max out with ten dead batteries. Oopsie.
Turtle your laptop figures are right on. The laptop can live off its own battery for about 2 hours(it's a 8 cell battery which I guess is unheard of in laptops), but it will kill my house battery in like 4 hours. If I just always leave it charged I get a good 9 hours before I'm at 50%. Thanks a lot for info I know you end up answering a lot of battery questions. I have read a lot about them, but much of it still goes over my head. I appreciate your time.
FYI. The gas Transits only come with one lead acid battery. It's an available option to order the 2 agm batteries. I only have the one battery, I can use my battery separator switch to use the house batteries as backup start batteries if it ever became necessary. It hasn't been needed yet.
The diesel comes standard with 2 batteries. Both gas version come standard with 1 battery. Ordering the 230 amp alternator option gets you 2 batteries. Ordering the upfitter switch set requires getting the 230 amp alternator and of course the second battery. Ford offers the twin battery option to meet the needs of trade persons to handle various small electronics.
Acvox, here is a link to the Body and Equipment Mounting Manual. It has everything you will ever want to know about your Transit and then some. Before drilling any holes or doing any direct wiring you should read it. https://www.fleet.ford.com/truckbbas/topics/2015/2015_Transit_BEMM_v1-0.pdf
Acvox, here is a link to the Body and Equipment Mounting Manual. It has everything you will ever want to know about your Transit and then some. Before drilling any holes or doing any direct wiring you should read it. https://www.fleet.ford.com/truckbbas/topics/2015/2015_Transit_BEMM_v1-0.pdf
Moot, your close but I did order and get the 230 amp alternator and only got the one wet cell battery under the drivers seat. Stuff like the user defined switches or the 110 inverter triggered the battery change. I'm sure other options required the dual batteries also, but not the 230 alt.
And looking at the above window sticker, wouldn't it have been cheaper cost to just order the interior upgrade package instead of all the options separately?
I thought I ordered the extra switch package but didn't get it. I did end up with the 230 amp alternator and dual AGM batteries. I believe my brother-in-law (Ford sales) and I had a failure to communicate.