Balmar 90 and 7 series. What to expect?

[john61ct]

Originally Posted by Paul L

So would only a fool think that a specifically built, premium priced, 100 amp alternator marketed to the marine aftermarket would deliver 60 amps for more than 45 minutes?

I try to be precise in my communications.

I was stating that the peak, only temporary maximum amps output is the number used across the industry.

I was not making any statement about the validity of your claim against any particular vendor.

It is very much the case that the ability of small-frame alts to actually produce high amps is very limited by temperature conditions.

And IMO anyone looking to get high amps output from any alt to charge a deep-cycling bank, needs to realize it is not a simple straightforward topic area.

[MikeFergie]

I see no comments about Bosch alternators on the site [emoji848]
This manufacturer makes most of the alternators for all of the high end BMW’s, Mercedes and VW,s . 90amp ratings on most of their alternators up to 120 amps.
I recently bought one to fit to my Yanmar but need to get a taco wire out fitted as it did not come with one on my model that bought.

[Stu Jackson]

Originally Posted by john61ct

>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
It is very much the case that the ability of small-frame alts to actually produce high amps is very limited by temperature conditions.

And IMO anyone looking to get high amps output from any alt to charge a deep-cycling bank, needs to realize it is not a simple straightforward topic area.

It is, however, a system management issue. I have addressed this with an external regulator and use of the Small Engine Mode. Others use Belt (Amp) Manager or both.

And it is not limited to Balmar. Really.

Alternator heat, Regulator Controls, Small Engine Mode

Alternator heat, Regulator Controls, Small Engine Mode

Small Engine Mode - discussion with link to the picture of the toggle switch: Alternator heat, Regulator Controls, Small Engine Mode

Small Engine Mode - the picture of the toggle switch Alternator Output Management with External Regulators [Small Engine Mode]

[Pizzazz]

I have been following these discussions for a while and spent some time playing with my system, modifying my Hitachi alternator for external regulation with a Blamer, etc. Overall, I think it was a wasted effort. My current setup, I think is optimal in terms of cost and efficiency:

- Cheap, $70 alternator, 14.7V, 80A. It provides rated output for about an hour then drops. No big deal. If you really want to run the alternator for hours (rare use case), it is best to provide external cooling via a 3" blower ($25). The key issue is that alternators are about 40% efficient, so an 80A alternator generates close to 2kW of heat at 15V. You need to remove this heat somehow not make the alternator bigger. By the way, using large alternators, optimized for say, 120A or 165A, means that their efficiency will drop further below 40% when you only need 50 or 60A.

- Field wire connected to the engine lights switch. This way you can always kill the alternator output at start up or if you are doing extensive motoring and are fully charged.

- Spare alternator and belts. At $70 these are consumable items, similar to belts. By the way, definitely use a cobbed belt - more efficient.

- if you change your battery chemistry, change the alternator as well. The cost is small relative to the cost of the bank.

This is it, the rest is just common sense. Keep your batteries in a cool, well ventilated space. Use golf cart batteries, best value for money, can take the 14.7V.

If you really want high current capability, you need to use a generator - much more efficient as it uses higher voltages, less current, less heat. May be the cheapest option is to buy a small gas generator ($300-400, no need for a Honda) and attach the generating unit (a 120V alternator without the rectifying diodes) to the boat diesel engine (adjust the rpms with pulley selection), then feed through your charger.

All these talk about custom alternators, configuring the Balmer units with small magnets (what a royal pain) is just going in the wrong direction. The fundamental issue with alternators is the low 12V voltage - they are OK for small current generation but become increasingly inadequate for currents over 100A. Even moving such large currents across the boat for hours on end is wasteful, no matter how big your cables are. It is OK for an inverter that feeds a microwave for a few minutes but not for hours on end.

I hope that helps.

SV Pizzazz

[kenbo]

^^^^^

[john61ct]

It is perfectly appropriate - for **some** use cases - to spend a boat buck or two on an alt setup that will reliably contribute a day or two's worth of House energy consumption in a couple hours of motoring.

Especially if doing so eliminates the need for a separate generator.

All depends on the context, other factors involved, owner's preferences etc, no one design decision applies to everyone.

If it makes sense for someone to do so, then the "how to" discussion does become relevant.

I don't think "efficiency" is in that sense very relevant, more of a theoretical exercise.

Sizing your alt so your maximum need is say half of its maximum potential is actually very sensible.

[Jerry Woodward]

Originally Posted by Pizzazz

- Cheap, $70 alternator, 14.7V, 80A. It provides rated output for about an hour then drops. No big deal. If you really want to run the alternator for hours (rare use case), it is best to provide external cooling via a 3" blower ($25). The key issue is that alternators are about 40% efficient, so an 80A alternator generates close to 2kW of heat at 15V. You need to remove this heat somehow not make the alternator bigger. By the way, using large alternators, optimized for say, 120A or 165A, means that their efficiency will drop further below 40% when you only need 50 or 60A.


SV Pizzazz

So you are saying that this 10SI alternator can deliver 80A at 14.7V for an hour without overheating? Sounds too good to be true. Do you have any data on the temp at which it begins to down grade the voltage?

[john61ct]

It is too good to be true, very high rpm to start with to get to rated max output.

The heat/output drop off depends on lots of variables.

Relocating the diodes, converting to a better external VR, and yes active cooling all help.

But if you need 80A continuous, go large-frame, all there is to it.

[akopac]

Hi Folks
I have a similar need to get a backup alternator for a Perkins 4.108 W/Ample Power Next Step 3 regulator, and electric tachometer Tap. I know I'll have to do some wiring/tinkering. I'm good at it. Which version of the Delco Alternator do I get?
10SI 105A 1 wire
10SI 105A 3 wire
10DN

Thanks

Andy

[kenbo]

The 10si 3wire I'd the best of the 3 posted. But if you can source a 12si that would be a better choice. Design for better cooling.

[wsmurdoch]

Do you want to continue to use your external regulator?

What kind of foot does your current alternator have? (How is it attached to the engine?)

[akopac]

It will take a single 1" or 2" foot. I have the adapter.

[wsmurdoch]

If you want to continue to use your Ample Power regulator, if you want to avoid the hassle of converting a new alternator to external regulation, and if you want a simple bolt in / plug in spare, then the DN10 might be your easiest option. My Ample Power alternator was a DN10 style alternator. Does your existing alternator look like the DN10 in the pictures at https://www.qualitypowerauto.com/ite...-regulator.htm especially the electrical connections on the rear? Do your spade connections look like these -- parallel to each other?

[akopac]

The current one is a Balmar 91-150-D. Sytem works awesome. Just need a good backup for a rainy day.

[wsmurdoch]

If it is this one https://sbo.sailboatowners.com/downl...n_45902785.pdf with a 2" foot, it looks like a 10DN case. In which case... I'd drop by an alternator shop with the Balmar in hand and ask them for a rebuilt replacement with the same size pulley and with the same clocked case. I doubt that it would run $50. It'd be a bolt in and plug in lower spec replacement that would get you home. You'd probably end up with a 1972 Cadillac Fleetwood alternator. It'd look like this https://shop.advanceautoparts.com/p/...999%7CL3*15587

More money would get you better https://www.qualitypowerauto.com/ite...-regulator.htm